------------[ cut here ]------------
ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x10 kernel/workqueue.c:1595
WARNING: CPU: 0 PID: 10638 at lib/debugobjects.c:488 debug_print_object+0x71/0xc0 lib/debugobjects.c:485
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 10638 Comm: kworker/u4:8 Not tainted 5.9.0-rc2-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+0x78/0xa0 lib/dump_stack.c:118
 panic+0x13c/0x30f kernel/panic.c:231
 __warn.cold.13+0x20/0x20 kernel/panic.c:600
 report_bug+0xc0/0xf0 lib/bug.c:198
 handle_bug+0x3f/0x70 arch/x86/kernel/traps.c:234
 exc_invalid_op+0x13/0x60 arch/x86/kernel/traps.c:254
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536
RIP: 0010:debug_print_object+0x71/0xc0 lib/debugobjects.c:485
Code: 8b 5b 10 89 15 94 5e d1 04 4c 8b 45 00 48 83 fb 05 77 31 48 8b 14 dd 20 df ba 83 4c 89 e6 48 c7 c7 e0 20 53 84 e8 ba 10 40 ff <0f> 0b 83 05 52 57 37 03 01 48 83 c4 18 5b 5d 41 5c c3 83 05 42 57
RSP: 0018:ffffc90003213bd0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000001
RDX: 0000000080000001 RSI: ffffffff846bc3e6 RDI: 00000000ffffffff
RBP: ffffffff84b129e0 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: ffff88812e41bae8 R12: ffffffff84505d85
R13: ffff888134fab488 R14: 0000000000000005 R15: ffffffff84b129e0
 __debug_check_no_obj_freed lib/debugobjects.c:967 [inline]
 debug_check_no_obj_freed+0x1bb/0x1dd lib/debugobjects.c:998
 slab_free_hook mm/slub.c:1540 [inline]
 slab_free_freelist_hook+0xae/0x130 mm/slub.c:1581
 slab_free mm/slub.c:3142 [inline]
 kfree+0xd8/0x320 mm/slub.c:4123
 device_release+0x1f/0x70 drivers/base/core.c:1800
 kobject_cleanup lib/kobject.c:704 [inline]
 kobject_release lib/kobject.c:735 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x7c/0x1c0 lib/kobject.c:752
 netdev_run_todo+0x1d9/0x290 net/core/dev.c:10112
 default_device_exit_batch+0x150/0x170 net/core/dev.c:10912
 cleanup_net+0x273/0x3d0 net/core/net_namespace.c:603
 process_one_work+0x26a/0x5f0 kernel/workqueue.c:2269
 worker_thread+0x38/0x380 kernel/workqueue.c:2415
 kthread+0x147/0x170 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Kernel Offset: disabled
Rebooting in 86400 seconds..