kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
------------[ cut here ]------------
WARNING: CPU: 3 PID: 13 at lib/ref_tracker.c:323 ref_tracker_free+0x61a/0x830 lib/ref_tracker.c:323
Modules linked in:
CPU: 3 UID: 0 PID: 13 Comm: kworker/u32:1 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 31 3c a6 fc 45 85 f6 0f 85 a6 00 00 00 e8 e3 40 a6 fc 48 8b 34 24 48 89 ef e8 e7 99 7f 06 90 <0f> 0b 90 bb ea ff ff ff e9 50 fd ff ff e8 c4 40 a6 fc 4c 8d 6d 44
RSP: 0018:ffffc900001f78a8 EFLAGS: 00010202
RAX: 0000000000000201 RBX: ffff88804b9d6000 RCX: 0000000000000000
RDX: 0000000000000202 RSI: ffffffff8de4f612 RDI: 0000000000000001
RBP: ffff8880237e8610 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90abac97 R11: 0000000000000000 R12: 1ffff9200003ef17
R13: ffffc900001f78d8 R14: 00000000048803fb R15: ffff88804b9d6018
FS:  0000000000000000(0000) GS:ffff8880977ba000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f736e104 CR3: 00000000656b2000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 netdev_tracker_free include/linux/netdevice.h:4369 [inline]
 netdev_put include/linux/netdevice.h:4386 [inline]
 netdev_put include/linux/netdevice.h:4382 [inline]
 netdev_watchdog_down net/sched/sch_generic.c:572 [inline]
 dev_deactivate_many+0x28d/0xd50 net/sched/sch_generic.c:1370
 dev_deactivate+0xf8/0x1c0 net/sched/sch_generic.c:1401
 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+0x9cf/0x1b70 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>