------------[ 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:767
WARNING: CPU: 0 PID: 29521 at lib/debugobjects.c:328 debug_print_object lib/debugobjects.c:325 [inline]
WARNING: CPU: 0 PID: 29521 at lib/debugobjects.c:328 __debug_check_no_obj_freed lib/debugobjects.c:785 [inline]
WARNING: CPU: 0 PID: 29521 at lib/debugobjects.c:328 debug_check_no_obj_freed+0x5c0/0x740 lib/debugobjects.c:817
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 29521 Comm: kworker/u4:17 Not tainted 5.2.0-rc7+ #15
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+0x28a/0x7c9 kernel/panic.c:219
 __warn+0x216/0x220 kernel/panic.c:576
 report_bug+0x190/0x290 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap+0xd7/0x450 arch/x86/kernel/traps.c:272
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:986
RIP: 0010:debug_print_object lib/debugobjects.c:325 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:785 [inline]
RIP: 0010:debug_check_no_obj_freed+0x5c0/0x740 lib/debugobjects.c:817
Code: 86 e7 4d fe 4c 89 fa 48 8b 4d b8 4c 8b 01 48 c7 c7 cc 57 66 88 48 c7 c6 9c 66 7e 88 44 89 e1 4c 8b 4d b0 31 c0 e8 a0 91 e6 fd <0f> 0b 48 8b 4d d0 48 8b 55 c8 ff 05 58 40 7c 05 48 b8 00 00 00 00
RSP: 0018:ffff888063cef700 EFLAGS: 00010046
RAX: 29bcf396ebc3f900 RBX: 1ffff11011cee98a RCX: ffff8880a82bc040
RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000
RBP: ffff888063cef7a0 R08: ffffffff815e8504 R09: ffffed1015d440c2
R10: ffffed1015d440c2 R11: 1ffff11015d440c1 R12: 0000000000000000
R13: 1ffff11011cee98c R14: ffff88808b882be0 R15: dffffc0000000000
 kfree+0xa0/0x120 mm/slab.c:3754
 kvfree+0x47/0x50 mm/util.c:460
 netdev_freemem+0x3e/0x60 net/core/dev.c:9098
 netdev_release+0x7e/0xb0 net/core/net-sysfs.c:1635
 device_release+0x74/0x1a0 drivers/base/core.c:1060
 kobject_cleanup+0x2f7/0x4c0 lib/kobject.c:691
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0xad/0xe0 lib/kobject.c:737
 netdev_run_todo+0xc6f/0xe00 net/core/dev.c:9003
 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:112
 default_device_exit_batch+0x71c/0x790 net/core/dev.c:9784
 ops_exit_list net/core/net_namespace.c:157 [inline]
 cleanup_net+0x64f/0x9f0 net/core/net_namespace.c:553
 process_one_work+0x814/0x1130 kernel/workqueue.c:2269
 worker_thread+0xc01/0x1640 kernel/workqueue.c:2415
 kthread+0x325/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

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