BUG: kernel NULL pointer dereference, address: 0000000000000648
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 8000000066d49067 P4D 8000000066d49067 PUD 0
Oops: Oops: 0002 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 16742 Comm: syz.1.4075 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:llc_ui_setsockopt+0x4e1/0x5f0 net/llc/af_llc.c:-1
Code: a1 f8 eb 4b e8 a0 bc 3d f8 4c 6b f3 64 49 8d 9f a0 06 00 00 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 3f 29 a1 f8 <4c> 89 33 eb 23 e8 75 bc 3d f8 4d 8d b7 0d 07 00 00 4c 89 f0 48 c1
RSP: 0000:ffffc90000007b98 EFLAGS: 00010246
RAX: 00000000000000c9 RBX: 0000000000000648 RCX: ffff88807e411e00
RDX: 0000000000000100 RSI: ffffffff8be33660 RDI: ffff8880555b0410
RBP: ffffc90000007c90 R08: ffffffff8fa38337 R09: 1ffffffff1f47066
R10: dffffc0000000000 R11: ffffffff8981edb0 R12: 1ffff92000000f78
R13: ffff8880555b0410 R14: 0000000000000001 R15: 0000000000000000
FS: 00005555921d2500(0000) GS:ffff888125c1a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000648 CR3: 00000000322ba000 CR4: 00000000003526f0
Call Trace:
expire_timers kernel/time/timer.c:1798 [inline]
__run_timers kernel/time/timer.c:2372 [inline]
__run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
run_timer_base kernel/time/timer.c:2393 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
handle_softirqs+0x283/0x870 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:1050 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5225
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 7f 46 eb 09 e8 2a 3e 36 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0000:ffffc9000f3a7558 EFLAGS: 00000282
RAX: fd708f2cf407ab00 RBX: 0000000000000000 RCX: fd708f2cf407ab00
RDX: 0000000000000000 RSI: ffffffff8be33660 RDI: ffffffff81911696
RBP: ffffc9000f3a75b0 R08: ffffffff8fa38337 R09: 1ffffffff1f47066
R10: dffffc0000000000 R11: fffffbfff1f47067 R12: ffff88807e411e00
R13: dffffc0000000000 R14: ffff888030763c00 R15: ffff8880b863ab58
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x17a0/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7145
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7169
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
skb_dequeue+0x10e/0x150 net/core/skbuff.c:3899
wireless_nlevent_flush net/wireless/wext-core.c:353 [inline]
wext_netdev_notifier_call+0x69/0x110 net/wireless/wext-core.c:371
notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
call_netdevice_notifiers net/core/dev.c:2281 [inline]
unregister_netdevice_many_notify+0x14d7/0x1ff0 net/core/dev.c:12215
unregister_netdevice_many net/core/dev.c:12278 [inline]
unregister_netdevice_queue+0x33c/0x380 net/core/dev.c:12122
unregister_netdevice include/linux/netdevice.h:3385 [inline]
__tun_detach+0xda4/0x1560 drivers/net/tun.c:621
tun_detach drivers/net/tun.c:637 [inline]
tun_chr_close+0x10a/0x1c0 drivers/net/tun.c:3433
__fput+0x44c/0xa70 fs/file_table.c:468
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7a0858ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe79f7b2c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 000000000004886c RCX: 00007f7a0858ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f7a087b7da0 R08: 0000000000000001 R09: 0000000a79f7b5bf
R10: 0000001b32c20000 R11: 0000000000000246 R12: 00007f7a087b5fac
R13: 00007f7a087b5fa0 R14: ffffffffffffffff R15: 00007ffe79f7b3e0
Modules linked in:
CR2: 0000000000000648
---[ end trace 0000000000000000 ]---
RIP: 0010:llc_ui_setsockopt+0x4e1/0x5f0 net/llc/af_llc.c:-1
Code: a1 f8 eb 4b e8 a0 bc 3d f8 4c 6b f3 64 49 8d 9f a0 06 00 00 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 3f 29 a1 f8 <4c> 89 33 eb 23 e8 75 bc 3d f8 4d 8d b7 0d 07 00 00 4c 89 f0 48 c1
RSP: 0000:ffffc90000007b98 EFLAGS: 00010246
RAX: 00000000000000c9 RBX: 0000000000000648 RCX: ffff88807e411e00
RDX: 0000000000000100 RSI: ffffffff8be33660 RDI: ffff8880555b0410
RBP: ffffc90000007c90 R08: ffffffff8fa38337 R09: 1ffffffff1f47066
R10: dffffc0000000000 R11: ffffffff8981edb0 R12: 1ffff92000000f78
R13: ffff8880555b0410 R14: 0000000000000001 R15: 0000000000000000
FS: 00005555921d2500(0000) GS:ffff888125c1a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000648 CR3: 00000000322ba000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: a1 f8 eb 4b e8 a0 bc movabs 0xf83dbca0e84bebf8,%eax
7: 3d f8
9: 4c 6b f3 64 imul $0x64,%rbx,%r14
d: 49 8d 9f a0 06 00 00 lea 0x6a0(%r15),%rbx
14: 48 89 d8 mov %rbx,%rax
17: 48 c1 e8 03 shr $0x3,%rax
1b: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
20: 74 08 je 0x2a
22: 48 89 df mov %rbx,%rdi
25: e8 3f 29 a1 f8 call 0xf8a12969
* 2a: 4c 89 33 mov %r14,(%rbx) <-- trapping instruction
2d: eb 23 jmp 0x52
2f: e8 75 bc 3d f8 call 0xf83dbca9
34: 4d 8d b7 0d 07 00 00 lea 0x70d(%r15),%r14
3b: 4c 89 f0 mov %r14,%rax
3e: 48 rex.W
3f: c1 .byte 0xc1