------------[ cut here ]------------
ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x90 kernel/workqueue.c:4943
WARNING: CPU: 1 PID: 9834 at lib/debugobjects.c:325 debug_print_object+0x160/0x250 lib/debugobjects.c:325
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 9834 Comm: kworker/u4:6 Not tainted 4.19.128-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2fe lib/dump_stack.c:118
 panic+0x26a/0x50e kernel/panic.c:186
 __warn.cold+0x20/0x46 kernel/panic.c:541
 report_bug+0x262/0x2a0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x1d7/0x310 arch/x86/kernel/traps.c:296
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038
RIP: 0010:debug_print_object+0x160/0x250 lib/debugobjects.c:325
Code: dd 60 f5 aa 87 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 bf 00 00 00 48 8b 14 dd 60 f5 aa 87 48 c7 c7 e0 ea aa 87 e8 4b 25 e6 fd <0f> 0b 83 05 83 06 37 06 01 48 83 c4 20 5b 5d 41 5c 41 5d c3 48 89
RSP: 0018:ffff88805674f8e8 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81535121 RDI: ffffed100ace9f0f
RBP: 0000000000000001 R08: ffff888086592000 R09: ffffed1015ce3eef
R10: ffffed1015ce3eee R11: ffff8880ae71f777 R12: ffffffff88ba0460
R13: ffffffff815888c0 R14: ffffffff8b859b48 R15: ffff888097b36320
 __debug_check_no_obj_freed lib/debugobjects.c:785 [inline]
 debug_check_no_obj_freed+0x28e/0x3e1 lib/debugobjects.c:817
 kfree+0xbb/0x220 mm/slab.c:3821
 kvfree+0x59/0x60 mm/util.c:452
 device_release+0x76/0x210 drivers/base/core.c:1061
 kobject_cleanup lib/kobject.c:662 [inline]
 kobject_release lib/kobject.c:691 [inline]
 kref_put include/linux/kref.h:70 [inline]
 kobject_put+0x17c/0x270 lib/kobject.c:708
 netdev_run_todo+0x4f1/0x740 net/core/dev.c:8996
 default_device_exit_batch+0x309/0x3c0 net/core/dev.c:9781
 ops_exit_list.isra.0+0xef/0x140 net/core/net_namespace.c:156
 cleanup_net+0x3bf/0x850 net/core/net_namespace.c:553
 process_one_work+0x892/0x1580 kernel/workqueue.c:2155
 worker_thread+0x96/0xe20 kernel/workqueue.c:2298
 kthread+0x30b/0x410 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

======================================================