==================================================================
BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0 net/rose/rose_timer.c:183
Read of size 2 at addr ffff88807f6ddc2a by task syz-executor/15553

CPU: 0 UID: 0 PID: 15553 Comm: syz-executor Not tainted 6.15.0-rc7-syzkaller-00082-g5cdb2c77c4c3 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xb4/0x290 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 rose_timer_expiry+0x471/0x4b0 net/rose/rose_timer.c:183
 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1789
 expire_timers kernel/time/timer.c:1840 [inline]
 __run_timers kernel/time/timer.c:2414 [inline]
 __run_timer_base+0x61a/0x860 kernel/time/timer.c:2426
 run_timer_base kernel/time/timer.c:2435 [inline]
 run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2445
 handle_softirqs+0x286/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
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+0x5a/0xb0 kernel/rcu/tree.c:736
Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 4c d3 7a 00 48 c7 c3 58 0b 77 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 34 8b 03 65 ff 0d 69 c6 ce 10 74 11 83 e0 04 c1 e8 02 5b
RSP: 0018:ffffc90004be6f00 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffff8880b8832b58 RCX: b337bf0e54a01200
RDX: 0000000000000000 RSI: ffffffff8bc1f3a0 RDI: ffffffff8bc1f360
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff81ab5cdd R12: ffff888057f69e00
R13: ffff8880292396c0 R14: ffffffff8d970c20 R15: dffffc0000000000
 rcu_read_unlock include/linux/rcupdate.h:869 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
 is_module_text_address+0x147/0x1e0 kernel/module/main.c:3745
 kernel_text_address+0x94/0xe0 kernel/extable.c:119
 __kernel_text_address+0xd/0x40 kernel/extable.c:79
 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369
 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4147 [inline]
 slab_alloc_node mm/slub.c:4196 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4203
 ptlock_alloc+0x20/0x70 mm/memory.c:7354
 ptlock_init include/linux/mm.h:3074 [inline]
 pagetable_pte_ctor include/linux/mm.h:3122 [inline]
 __pte_alloc_one_noprof include/asm-generic/pgalloc.h:73 [inline]
 pte_alloc_one+0x6d/0x160 arch/x86/mm/pgtable.c:17
 __pte_alloc+0x25/0x160 mm/memory.c:430
 copy_pte_range mm/memory.c:1100 [inline]
 copy_pmd_range+0x6903/0x7000 mm/memory.c:1255
 copy_pud_range mm/memory.c:1292 [inline]
 copy_p4d_range mm/memory.c:1316 [inline]
 copy_page_range+0x95c/0xd40 mm/memory.c:1410
 dup_mmap kernel/fork.c:727 [inline]
 dup_mm kernel/fork.c:1735 [inline]
 copy_mm+0x126a/0x2160 kernel/fork.c:1787
 copy_process+0x16d3/0x3b80 kernel/fork.c:2430
 kernel_clone+0x21e/0x870 kernel/fork.c:2845
 __do_sys_clone kernel/fork.c:2988 [inline]
 __se_sys_clone kernel/fork.c:2972 [inline]
 __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2972
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe2d2f851d3
Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffc0751cb38 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe2d2f851d3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055555b3967d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000005da8c R15: 00007ffc0751ccd0
 </TASK>

Allocated by task 15553:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155
 ip6_route_info_create+0x4b3/0x1360 net/ipv6/route.c:3802
 ip6_route_add+0x28/0x160 net/ipv6/route.c:3896
 addrconf_prefix_route net/ipv6/addrconf.c:2487 [inline]
 inet6_addr_add+0x6b2/0xc00 net/ipv6/addrconf.c:3052
 inet6_rtm_newaddr+0x93d/0xd20 net/ipv6/addrconf.c:5063
 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6955
 netlink_rcv_skb+0x219/0x490 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x75b/0x8d0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:727
 __sys_sendto+0x3bd/0x520 net/socket.c:2180
 __do_sys_sendto net/socket.c:2187 [inline]
 __se_sys_sendto net/socket.c:2183 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2183
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 23:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2380 [inline]
 slab_free mm/slub.c:4642 [inline]
 kfree+0x193/0x440 mm/slub.c:4841
 rcu_do_batch kernel/rcu/tree.c:2568 [inline]
 rcu_core+0xca8/0x1710 kernel/rcu/tree.c:2824
 handle_softirqs+0x286/0x870 kernel/softirq.c:579
 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:164
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:548
 __call_rcu_common kernel/rcu/tree.c:3082 [inline]
 call_rcu+0x142/0x990 kernel/rcu/tree.c:3202
 call_rcu_hurry include/linux/rcupdate.h:115 [inline]
 fib6_info_release include/net/ip6_fib.h:343 [inline]
 ip6_route_info_create+0xab1/0x1360 net/ipv6/route.c:3882
 ip6_route_add+0x28/0x160 net/ipv6/route.c:3896
 addrconf_prefix_route net/ipv6/addrconf.c:2487 [inline]
 inet6_addr_add+0x6b2/0xc00 net/ipv6/addrconf.c:3052
 inet6_rtm_newaddr+0x93d/0xd20 net/ipv6/addrconf.c:5063
 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6955
 netlink_rcv_skb+0x219/0x490 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x75b/0x8d0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:727
 __sys_sendto+0x3bd/0x520 net/socket.c:2180
 __do_sys_sendto net/socket.c:2187 [inline]
 __se_sys_sendto net/socket.c:2183 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2183
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807f6ddc00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff88807f6ddc00, ffff88807f6dde00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807f6dd400 pfn:0x7f6dc
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 ffff88801a041c80 ffffea0000ccae10 ffffea0001fb9b10
raw: ffff88807f6dd400 000000000010000f 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801a041c80 ffffea0000ccae10 ffffea0001fb9b10
head: ffff88807f6dd400 000000000010000f 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0001fdb701 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 12, tgid 12 (kworker/u8:0), ts 93387443566, free_ts 93321711948
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1714
 prep_new_page mm/page_alloc.c:1722 [inline]
 get_page_from_freelist+0x21ce/0x22b0 mm/page_alloc.c:3684
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4966
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2450 [inline]
 allocate_slab+0x8a/0x3b0 mm/slub.c:2618
 new_slab mm/slub.c:2672 [inline]
 ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858
 __slab_alloc mm/slub.c:3948 [inline]
 __slab_alloc_node mm/slub.c:4023 [inline]
 slab_alloc_node mm/slub.c:4184 [inline]
 __kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4353
 kmalloc_noprof include/linux/slab.h:905 [inline]
 batadv_forw_packet_alloc+0x1e9/0x390 net/batman-adv/send.c:519
 batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:571 [inline]
 batadv_iv_ogm_queue_add+0x85f/0xd30 net/batman-adv/bat_iv_ogm.c:678
 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:841 [inline]
 batadv_iv_ogm_schedule+0x81c/0xea0 net/batman-adv/bat_iv_ogm.c:876
 batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1720
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page last free pid 5827 tgid 5827 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1258 [inline]
 __free_frozen_pages+0xb0e/0xcd0 mm/page_alloc.c:2721
 __slab_free+0x326/0x400 mm/slub.c:4553
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4147 [inline]
 slab_alloc_node mm/slub.c:4196 [inline]
 kmem_cache_alloc_node_noprof+0x1bb/0x3c0 mm/slub.c:4248
 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:658
 netlink_sendmsg+0x5c6/0xb30 net/netlink/af_netlink.c:1858
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:727
 __sys_sendto+0x3bd/0x520 net/socket.c:2180
 __do_sys_sendto net/socket.c:2187 [inline]
 __se_sys_sendto net/socket.c:2183 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2183
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88807f6ddb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807f6ddb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88807f6ddc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88807f6ddc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807f6ddd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	f0 48 c1 e8 03       	lock shr $0x3,%rax
   5:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1)
   a:	74 08                	je     0x14
   c:	4c 89 f7             	mov    %r14,%rdi
   f:	e8 4c d3 7a 00       	call   0x7ad360
  14:	48 c7 c3 58 0b 77 92 	mov    $0xffffffff92770b58,%rbx
  1b:	49 03 1e             	add    (%r14),%rbx
  1e:	48 89 d8             	mov    %rbx,%rax
  21:	48 c1 e8 03          	shr    $0x3,%rax
  25:	42 0f b6 04 38       	movzbl (%rax,%r15,1),%eax
* 2a:	84 c0                	test   %al,%al <-- trapping instruction
  2c:	75 34                	jne    0x62
  2e:	8b 03                	mov    (%rbx),%eax
  30:	65 ff 0d 69 c6 ce 10 	decl   %gs:0x10cec669(%rip)        # 0x10cec6a0
  37:	74 11                	je     0x4a
  39:	83 e0 04             	and    $0x4,%eax
  3c:	c1 e8 02             	shr    $0x2,%eax
  3f:	5b                   	pop    %rbx