------------[ 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: 1 PID: 7 at lib/debugobjects.c:328 debug_print_object+0x168/0x210 lib/debugobjects.c:325
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 5.1.0-rc2+ #1
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+0x113/0x167 lib/dump_stack.c:113
 panic+0x212/0x40b kernel/panic.c:214
 __warn.cold.8+0x1b/0x38 kernel/panic.c:571
 report_bug+0x1a4/0x200 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap+0x11b/0x200 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:973
RIP: 0010:debug_print_object+0x168/0x210 lib/debugobjects.c:325
Code: 1f 87 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 92 00 00 00 48 8b 14 dd 00 a0 1f 87 4c 89 fe 48 c7 c7 a0 95 1f 87 e8 1b 49 41 fe <0f> 0b 83 05 e3 5b d8 05 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffff8880aa367840 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000004 RSI: 0000000000000008 RDI: ffffffff89cc69e0
RBP: ffff8880aa367880 R08: ffffed1015d63ef1 R09: ffffed1015d63ef0
R10: ffffed1015d63ef0 R11: ffff8880aeb1f787 R12: 0000000000000001
R13: ffffffff881a8500 R14: ffffffff8157dbd0 R15: ffffffff871f9c20
 __debug_check_no_obj_freed lib/debugobjects.c:785 [inline]
 debug_check_no_obj_freed+0x264/0x472 lib/debugobjects.c:817
 kfree+0xbd/0x220 mm/slab.c:3820
 kvfree+0x2c/0x30 mm/util.c:459
 netdev_freemem+0x47/0x60 net/core/dev.c:9083
 netdev_release+0x6c/0x90 net/core/net-sysfs.c:1637
 device_release+0x71/0x1d0 drivers/base/core.c:1064
 kobject_cleanup lib/kobject.c:662 [inline]
 kobject_release lib/kobject.c:691 [inline]
 kref_put include/linux/kref.h:67 [inline]
 kobject_put.cold.9+0x229/0x27c lib/kobject.c:708
 netdev_run_todo+0x4c1/0x6a0 net/core/dev.c:8988
 rtnl_unlock+0x9/0x10 net/core/rtnetlink.c:116
 default_device_exit_batch+0x2e9/0x3d0 net/core/dev.c:9769
 ops_exit_list.isra.5+0xd3/0x120 net/core/net_namespace.c:156
 cleanup_net+0x363/0x840 net/core/net_namespace.c:551
 process_one_work+0x830/0x16a0 kernel/workqueue.c:2269
 worker_thread+0x85/0xb60 kernel/workqueue.c:2415
 kthread+0x324/0x3e0 kernel/kthread.c:253
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

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