------------[ cut here ]------------ ODEBUG: free active (active state 0) object: ffff88804e408890 object type: timer_list hint: rose_t0timer_expiry+0x0/0x560 net/rose/rose_link.c:-1 WARNING: lib/debugobjects.c:615 at debug_print_object lib/debugobjects.c:612 [inline], CPU#0: syz.4.15364/23868 WARNING: lib/debugobjects.c:615 at __debug_check_no_obj_freed lib/debugobjects.c:1099 [inline], CPU#0: syz.4.15364/23868 WARNING: lib/debugobjects.c:615 at debug_check_no_obj_freed+0x405/0x550 lib/debugobjects.c:1129, CPU#0: syz.4.15364/23868 Modules linked in: CPU: 0 UID: 0 PID: 23868 Comm: syz.4.15364 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:debug_print_object lib/debugobjects.c:612 [inline] RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1099 [inline] RIP: 0010:debug_check_no_obj_freed+0x44a/0x550 lib/debugobjects.c:1129 Code: 89 44 24 20 e8 17 70 77 fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 c0 af 27 8c 48 c7 c2 40 b5 27 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: ffffffff8a95dab0 RBX: ffffffff9a4d2030 RCX: 0000000000000000 RDX: ffffffff8c27b540 RSI: ffffffff8c27afc0 RDI: ffffffff901bf080 RBP: ffffffff8bcf3c40 R08: ffff88804e408890 R09: ffffffff8bcf4f60 R10: dffffc0000000000 R11: ffffffff81b1d860 R12: ffff88804e408a00 R13: ffffffff901bf080 R14: ffff88804e408000 R15: ffff88804e408890 FS: 00007fd329bd56c0(0000) GS:ffff888125468000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000000c038 CR3: 000000009aeec000 CR4: 00000000003526f0 Call Trace: slab_free_hook mm/slub.c:2618 [inline] slab_free mm/slub.c:6124 [inline] kfree+0x13a/0x630 mm/slub.c:6442 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 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x6c/0xb0 kernel/rcu/tree.c:752 Code: 85 00 48 c7 c3 58 b9 1c 93 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d 59 da 70 11 74 11 83 e0 04 e8 02 5b 41 5e 41 5f c3 cc cc cc cc cc e8 41 08 89 ff eb e8 48 RSP: 0018:ffffc90003ecf388 EFLAGS: 00000202 RAX: 0000000000000004 RBX: ffff8880b8633958 RCX: 0000000080000002 RDX: ffff88804c429e40 RSI: ffffffff8c27a960 RDI: ffffffff8c27a920 RBP: 0000000000000001 R08: ffff88804c429e40 R09: 0000000000000002 R10: 000000000000000a R11: 0000000000000000 R12: ffff88807cc7ba58 R13: ffff88804b940000 R14: ffffffff8e1b0790 R15: dffffc0000000000 rcu_read_lock_held_common kernel/rcu/update.c:109 [inline] rcu_read_lock_held+0x15/0x50 kernel/rcu/update.c:349 __rcuref_put include/linux/rcuref.h:103 [inline] rcuref_put+0x2f/0x170 include/linux/rcuref.h:173 dst_release+0x24/0x1b0 net/core/dst.c:168 refdst_drop include/net/dst.h:272 [inline] skb_dst_drop include/net/dst.h:284 [inline] ip_mc_finish_output+0x158/0x2d0 net/ipv4/ip_output.c:360 NF_HOOK include/linux/netfilter.h:318 [inline] ip_mc_output+0x25c/0x590 net/ipv4/ip_output.c:401 ip_local_out net/ipv4/ip_output.c:131 [inline] ip_send_skb+0x74/0x100 net/ipv4/ip_output.c:1508 udp_send_skb+0xb04/0x1510 net/ipv4/udp.c:1195 udp_sendmsg+0x1a35/0x22f0 net/ipv4/udp.c:1485 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0x894/0xad0 net/socket.c:2591 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2645 __sys_sendmmsg+0x27c/0x4e0 net/socket.c:2734 __do_sys_sendmmsg net/socket.c:2761 [inline] __se_sys_sendmmsg net/socket.c:2758 [inline] __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2758 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd32b99c799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd329bd5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007fd32bc16090 RCX: 00007fd32b99c799 RDX: 000000000800001d RSI: 0000200000007fc0 RDI: 0000000000000004 RBP: 00007fd32ba32bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd32bc16128 R14: 00007fd32bc16090 R15: 00007ffc56fdcd48 ---------------- Code disassembly (best guess): 0: 89 44 24 20 mov %eax,0x20(%rsp) 4: e8 17 70 77 fd call 0xfd777020 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 c0 af 27 8c mov $0xffffffff8c27afc0,%rsi 1c: 48 c7 c2 40 b5 27 8c mov $0xffffffff8c27b540,%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