process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
------------[ cut here ]------------
WARNING: lib/ref_tracker.c:323 at ref_tracker_free+0x61a/0x830 lib/ref_tracker.c:323, CPU#2: kworker/u32:7/1140
Modules linked in:
CPU: 2 UID: 0 PID: 1140 Comm: kworker/u32:7 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: events_unbound linkwatch_event
RIP: 0010:ref_tracker_free+0x61a/0x830 lib/ref_tracker.c:323
Code: 00 44 8b 73 18 31 ff 44 89 f6 e8 c1 d4 df fc 45 85 f6 0f 85 a6 00 00 00 e8 13 da df fc 48 8b 34 24 48 89 ef e8 d7 3a 99 06 90 <0f> 0b 90 bb ea ff ff ff e9 50 fd ff ff e8 f4 d9 df fc 4c 8d 6d 44
RSP: 0000:ffffc90004faf828 EFLAGS: 00010202
RAX: 0000000000000201 RBX: ffff888043c193c0 RCX: 0000000000000000
RDX: 0000000000000202 RSI: ffffffff8dac831b RDI: 0000000000000001
RBP: ffff888043a28618 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff9088b3d7 R11: ffff888027a0aff0 R12: 1ffff920009f5f07
R13: ffffc90004faf858 R14: 00000000078204a6 R15: ffff888043c193d8
FS:  0000000000000000(0000) GS:ffff888097902000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000c35e3fc CR3: 0000000073c88000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 netdev_tracker_free include/linux/netdevice.h:4420 [inline]
 netdev_put include/linux/netdevice.h:4437 [inline]
 netdev_put include/linux/netdevice.h:4433 [inline]
 netdev_watchdog_down net/sched/sch_generic.c:575 [inline]
 dev_deactivate_many+0x28d/0xc40 net/sched/sch_generic.c:1366
 dev_deactivate+0xf8/0x1c0 net/sched/sch_generic.c:1397
 linkwatch_do_dev+0x11e/0x160 net/core/link_watch.c:184
 __linkwatch_run_queue+0x2a7/0x8a0 net/core/link_watch.c:244
 linkwatch_event+0x8f/0xc0 net/core/link_watch.c:304
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>