BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 1d9a0d067 P4D 1d9a0d067 PUD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 9 Comm: kworker/u4:1 Not tainted 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_unbound linkwatch_event
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09d50 EFLAGS: 00010202
RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881f5dc0fc0
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e1fb31c0
RBP: ffff8881f6e09d90 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc13a4 R11: 1ffff1103edc13a4 R12: 00000000ffffb378
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e1fb31c0
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001e2c5e000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 call_timer_fn+0x3c/0x380 kernel/time/timer.c:1448
 expire_timers kernel/time/timer.c:1493 [inline]
 __run_timers+0x81d/0xb60 kernel/time/timer.c:1817
 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x236/0x660 kernel/softirq.c:292
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1086
 </IRQ>
 do_softirq+0xf9/0x140 kernel/softirq.c:337
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:189
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline]
 _raw_spin_unlock_bh+0x51/0x60 kernel/locking/spinlock.c:207
 spin_unlock_bh include/linux/spinlock.h:383 [inline]
 br_port_carrier_check+0x5b1/0x740 net/bridge/br_if.c:89
 br_device_event+0x3cb/0x790 net/bridge/br.c:89
 notifier_call_chain kernel/notifier.c:98 [inline]
 __raw_notifier_call_chain kernel/notifier.c:399 [inline]
 raw_notifier_call_chain+0xa0/0x120 kernel/notifier.c:406
 call_netdevice_notifiers_info net/core/dev.c:1670 [inline]
 netdev_state_change+0x102/0x1a0 net/core/dev.c:1273
 linkwatch_do_dev+0x102/0x140 net/core/link_watch.c:159
 __linkwatch_run_queue+0x412/0x7e0 net/core/link_watch.c:205
 linkwatch_event+0x4c/0x60 net/core/link_watch.c:244
 process_one_work+0x73b/0xcc0 kernel/workqueue.c:2290
 worker_thread+0xa5c/0x13b0 kernel/workqueue.c:2436
 kthread+0x31e/0x3a0 kernel/kthread.c:288
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354
Modules linked in:
CR2: 0000000000000000
---[ end trace dabb675d9854bd45 ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09d50 EFLAGS: 00010202
RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881f5dc0fc0
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e1fb31c0
RBP: ffff8881f6e09d90 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc13a4 R11: 1ffff1103edc13a4 R12: 00000000ffffb378
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e1fb31c0
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001e2c5e000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600