------------[ cut here ]------------
ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x90 /./arch/x86/include/asm/paravirt.h:768
WARNING: CPU: 1 PID: 474 at lib/debugobjects.c:484 debug_print_object /lib/debugobjects.c:481 [inline]
WARNING: CPU: 1 PID: 474 at lib/debugobjects.c:484 __debug_check_no_obj_freed /lib/debugobjects.c:963 [inline]
WARNING: CPU: 1 PID: 474 at lib/debugobjects.c:484 debug_check_no_obj_freed+0x464/0x5b0 /lib/debugobjects.c:994
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 474 Comm: kworker/u4:6 Not tainted 5.2.0+ #37
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+0x1d8/0x2f8 /lib/dump_stack.c:113
 panic+0x29b/0x7d9 /kernel/panic.c:219
 __warn+0x22f/0x230 /kernel/panic.c:576
 report_bug+0x190/0x290 /lib/bug.c:186
 fixup_bug /arch/x86/kernel/traps.c:179 [inline]
 do_error_trap+0xd7/0x440 /arch/x86/kernel/traps.c:272
 do_invalid_op+0x36/0x40 /arch/x86/kernel/traps.c:291
 invalid_op+0x23/0x30 /arch/x86/entry/entry_64.S:1026
RIP: 0010:debug_print_object /lib/debugobjects.c:481 [inline]
RIP: 0010:__debug_check_no_obj_freed /lib/debugobjects.c:963 [inline]
RIP: 0010:debug_check_no_obj_freed+0x464/0x5b0 /lib/debugobjects.c:994
Code: 08 48 89 df e8 6d 95 4b fe 4c 8b 03 48 c7 c7 0e 19 88 88 48 c7 c6 8d 9c a0 88 4c 89 e2 44 89 f9 4d 89 e9 31 c0 e8 8c ff e2 fd <0f> 0b 4c 8b 6d a8 ff 05 24 76 98 05 49 83 c5 30 4c 89 e8 48 c1 e8
RSP: 0018:ffff8880a85df708 EFLAGS: 00010046
RAX: fe5b51a0453af800 RBX: ffffffff88cd9980 RCX: ffff8880a85d2640
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff8880a85df7a0 R08: ffffffff818110c9 R09: ffffed1015d640c2
R10: ffffed1015d640c2 R11: 0000000000000000 R12: ffffffff8893b3ff
R13: ffffffff814eeb90 R14: dffffc0000000000 R15: 0000000000000000
 kfree+0x107/0x200 /mm/slab.c:3755
 kvfree+0x47/0x50 /mm/util.c:488
 netdev_freemem+0x3e/0x60 /net/core/dev.c:9088
 netdev_release+0x79/0xa0 /net/core/net-sysfs.c:1635
 device_release+0x74/0x1a0 /drivers/base/core.c:1060
 kobject_cleanup+0x2f7/0x4c0 /lib/kobject.c:693
 kobject_release /lib/kobject.c:722 [inline]
 kref_put /./include/linux/kref.h:65 [inline]
 kobject_put+0xad/0xe0 /lib/kobject.c:739
 netdev_run_todo+0xc6f/0xe20 /net/core/dev.c:8993
 rtnl_unlock+0xe/0x10 /net/core/rtnetlink.c:112
 default_device_exit_batch+0x719/0x790 /net/core/dev.c:9774
 ops_exit_list /net/core/net_namespace.c:175 [inline]
 cleanup_net+0x77c/0xb30 /net/core/net_namespace.c:594
 process_one_work+0x83b/0x1150 /kernel/workqueue.c:2269
 worker_thread+0xc01/0x1630 /kernel/workqueue.c:2415
 kthread+0x332/0x350 /kernel/kthread.c:255
 ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..