------------[ cut here ]------------
WARNING: CPU: 0 PID: 2433 at net/xfrm/xfrm_state.c:2197 xfrm_state_fini+0x2a0/0x340 net/xfrm/xfrm_state.c:2197
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 2433 Comm: kworker/u4:5 Not tainted 4.9.141+ #1
Workqueue: netns cleanup_net
 ffff8801c7d4f940 ffffffff81b42e79 ffffffff82a38ce0 00000000ffffffff
 ffffffff82cb9500 0000000000000000 0000000000000009 ffff8801c7d4fa00
 ffffffff813f7125 0000000041b58ab3 ffffffff82e2b62b ffffffff813f6f66
Call Trace:
 [<ffffffff81b42e79>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b42e79>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff813f7125>] panic+0x1bf/0x39f kernel/panic.c:179
 [<ffffffff813f7362>] __warn.cold.8+0x2f/0x2f kernel/panic.c:542
 [<ffffffff810dc02c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
 [<ffffffff82658880>] xfrm_state_fini+0x2a0/0x340 net/xfrm/xfrm_state.c:2197
 [<ffffffff82639cad>] xfrm_net_exit+0x2d/0x30 net/xfrm/xfrm_policy.c:3119
 [<ffffffff822e3d70>] ops_exit_list.isra.0+0xb0/0x160 net/core/net_namespace.c:136
 [<ffffffff822e6ad2>] cleanup_net+0x3f2/0x8b0 net/core/net_namespace.c:473
 [<ffffffff81131001>] process_one_work+0x831/0x15f0 kernel/workqueue.c:2092
 [<ffffffff81131e96>] worker_thread+0xd6/0x1140 kernel/workqueue.c:2226
 [<ffffffff81142c3d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff82817a5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Kernel Offset: disabled
Rebooting in 86400 seconds..