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#0: kworker/u32:4/83
Modules linked in:
CPU: 0 UID: 0 PID: 83 Comm: kworker/u32:4 Not tainted syzkaller #0 PREEMPT(full) 
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 62 e6 fc 45 85 f6 0f 85 a6 00 00 00 e8 03 68 e6 fc 48 8b 34 24 48 89 ef e8 17 a9 87 06 90 <0f> 0b 90 bb ea ff ff ff e9 50 fd ff ff e8 e4 67 e6 fc 4c 8d 6d 44
RSP: 0018:ffffc9000107f828 EFLAGS: 00010202
RAX: 0000000000000201 RBX: ffff888072109a00 RCX: 0000000000000000
RDX: 0000000000000202 RSI: ffffffff8d89f477 RDI: 0000000000000001
RBP: ffff888027b58618 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff9065eed7 R11: 00000000966b2a1d R12: 1ffff9200020ff07
R13: ffffc9000107f858 R14: 00000000052403c3 R15: ffff888072109a18
FS:  0000000000000000(0000) GS:ffff8880979a5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff7b959ef4 CR3: 0000000063378000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 netdev_tracker_free include/linux/netdevice.h:4395 [inline]
 netdev_put include/linux/netdevice.h:4412 [inline]
 netdev_put include/linux/netdevice.h:4408 [inline]
 netdev_watchdog_down net/sched/sch_generic.c:575 [inline]
 dev_deactivate_many+0x28d/0xd50 net/sched/sch_generic.c:1373
 dev_deactivate+0xf8/0x1c0 net/sched/sch_generic.c:1404
 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:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 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>