==================================================================
BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x46a/0x4b0 net/rose/rose_timer.c:183
Read of size 2 at addr ffff88802f33b82a by task cmp/11268

CPU: 0 PID: 11268 Comm: cmp Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xac/0x220 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 rose_timer_expiry+0x46a/0x4b0 net/rose/rose_timer.c:183
 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x52d/0x7d0 kernel/time/timer.c:2022
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:vma_prev include/linux/mm.h:-1 [inline]
RIP: 0010:do_mprotect_pkey+0x4a7/0xc30 mm/mprotect.c:756
Code: 8f 18 b9 ff bb f4 ff ff ff 48 8b 44 24 28 48 89 44 24 50 4c 8b 74 24 48 48 8d bc 24 40 01 00 00 31 f6 e8 5c dd 8d 08 49 89 c7 <48> 8b 44 24 60 42 80 3c 20 00 74 08 4c 89 f7 e8 55 5e 10 00 4d 8b
RSP: 0018:ffffc9000ec6fd00 EFLAGS: 00000282
RAX: ffff888077c52300 RBX: 00000000fffffff4 RCX: ffff88805a7e5a00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000ec6fee8 R08: ffff88805a7e5a00 R09: 0000000000000003
R10: 0000000000000002 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff888077c52600 R15: ffff888077c52300
 __do_sys_mprotect mm/mprotect.c:840 [inline]
 __se_sys_mprotect mm/mprotect.c:837 [inline]
 __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:837
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9df44a22c7
Code: 89 3d fd 3f 01 00 eb 90 0f 1f 00 f7 d8 89 05 f0 3f 01 00 48 c7 c0 ff ff ff ff eb 91 0f 1f 80 00 00 00 00 b8 0a 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8d 0d c9 3f 01 00 f7 d8 89 01 48 83
RSP: 002b:00007fff3ddb97e8 EFLAGS: 00000206 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 00007f9df447f050 RCX: 00007f9df44a22c7
RDX: 0000000000000001 RSI: 0000000000001000 RDI: 00007f9df41c9000
RBP: 00007fff3ddb9ab0 R08: 0000000000000000 R09: 00007f9df421b870
R10: 00007f9df447f050 R11: 0000000000000206 R12: 0000000000000010
R13: 000001695dcc2a10 R14: 0000000000000000 R15: 00007f9df44b6310
 </TASK>

Allocated by task 573:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
 kmalloc include/linux/slab.h:600 [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:561 [inline]
 batadv_iv_ogm_queue_add+0x77b/0xcf0 net/batman-adv/bat_iv_ogm.c:669
 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:848 [inline]
 batadv_iv_ogm_schedule+0xab3/0xe90 net/batman-adv/bat_iv_ogm.c:867
 batadv_iv_send_outstanding_bat_ogm_packet+0x731/0x840 net/batman-adv/bat_iv_ogm.c:1711
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

Freed by task 7814:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1806 [inline]
 slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1832
 slab_free mm/slub.c:3816 [inline]
 __kmem_cache_free+0xba/0x1f0 mm/slub.c:3829
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
 insert_work+0x3d/0x310 kernel/workqueue.c:1651
 __queue_work+0xd2c/0x1020 kernel/workqueue.c:1804
 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1746 [inline]
 __run_timers+0x558/0x7d0 kernel/time/timer.c:2022
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687

Second to last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
 kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3452
 mld_clear_delrec+0x193/0x5d0 net/ipv6/mcast.c:824
 ipv6_mc_destroy_dev+0x45/0x590 net/ipv6/mcast.c:2795
 addrconf_ifdown+0x139f/0x1880 net/ipv6/addrconf.c:3969
 addrconf_notify+0x6c6/0x1010 net/ipv6/addrconf.c:-1
 notifier_call_chain+0x197/0x390 kernel/notifier.c:93
 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
 call_netdevice_notifiers net/core/dev.c:2078 [inline]
 unregister_netdevice_many_notify+0xf36/0x1810 net/core/dev.c:11074
 unregister_netdevice_many net/core/dev.c:11130 [inline]
 default_device_exit_batch+0x9cb/0xa60 net/core/dev.c:11608
 ops_exit_list net/core/net_namespace.c:178 [inline]
 cleanup_net+0x77f/0xb90 net/core/net_namespace.c:652
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

The buggy address belongs to the object at ffff88802f33b800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff88802f33b800, ffff88802f33ba00)

The buggy address belongs to the physical page:
page:ffffea0000bcce00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2f338
head:ffffea0000bcce00 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017841c80 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
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 3862, tgid 3862 (kworker/u4:1), ts 13467300697, free_ts 0
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 alloc_slab_page+0x5d/0x170 mm/slub.c:1876
 allocate_slab mm/slub.c:2023 [inline]
 new_slab+0x87/0x2e0 mm/slub.c:2076
 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
 __slab_alloc mm/slub.c:3329 [inline]
 __slab_alloc_node mm/slub.c:3382 [inline]
 slab_alloc_node mm/slub.c:3475 [inline]
 __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524
 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 alloc_bprm+0x56/0x9c0 fs/exec.c:1538
 kernel_execve+0x98/0x9c0 fs/exec.c:2023
 call_usermodehelper_exec_async+0x20b/0x350 kernel/umh.c:110
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802f33b700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802f33b780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802f33b800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88802f33b880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802f33b900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess), 4 bytes skipped:
   0:	bb f4 ff ff ff       	mov    $0xfffffff4,%ebx
   5:	48 8b 44 24 28       	mov    0x28(%rsp),%rax
   a:	48 89 44 24 50       	mov    %rax,0x50(%rsp)
   f:	4c 8b 74 24 48       	mov    0x48(%rsp),%r14
  14:	48 8d bc 24 40 01 00 	lea    0x140(%rsp),%rdi
  1b:	00
  1c:	31 f6                	xor    %esi,%esi
  1e:	e8 5c dd 8d 08       	call   0x88ddd7f
  23:	49 89 c7             	mov    %rax,%r15
* 26:	48 8b 44 24 60       	mov    0x60(%rsp),%rax <-- trapping instruction
  2b:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1)
  30:	74 08                	je     0x3a
  32:	4c 89 f7             	mov    %r14,%rdi
  35:	e8 55 5e 10 00       	call   0x105e8f
  3a:	4d                   	rex.WRB
  3b:	8b                   	.byte 0x8b