------------[ cut here ]------------
WARNING: CPU: 1 PID: 7779 at net/xfrm/xfrm_policy.c:2982 xfrm_policy_fini+0x266/0x2f0 net/xfrm/xfrm_policy.c:2982()
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 7779 Comm: kworker/u4:12 Not tainted 4.4.159+ #108
Workqueue: netns cleanup_net
 0000000000000000 556841726e1203f7 ffff8801c0aaf930 ffffffff81a994bd
 ffffffff828354e0 ffff8800b7f017c0 ffffffff82a90f80 0000000000000009
 0000000000000ba6 ffff8801c0aaf9f0 ffffffff813a1034 0000000041b58ab3
Call Trace:
 [<ffffffff81a994bd>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81a994bd>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff813a1034>] panic+0x19e/0x359 kernel/panic.c:112
 [<ffffffff813a1224>] warn_slowpath_common.cold.6+0x20/0x20 kernel/panic.c:455
 [<ffffffff810d4389>] warn_slowpath_null+0x29/0x30 kernel/panic.c:492
 [<ffffffff82537a86>] xfrm_policy_fini+0x266/0x2f0 net/xfrm/xfrm_policy.c:2982
 [<ffffffff82537b35>] xfrm_net_exit+0x25/0x30 net/xfrm/xfrm_policy.c:3043
 [<ffffffff82202930>] ops_exit_list.isra.0+0xb0/0x160 net/core/net_namespace.c:134
 [<ffffffff82205782>] cleanup_net+0x3f2/0x880 net/core/net_namespace.c:452
 [<ffffffff81122cb4>] process_one_work+0x824/0x1670 kernel/workqueue.c:2064
 [<ffffffff81123bd9>] worker_thread+0xd9/0x1060 kernel/workqueue.c:2196
 [<ffffffff81134038>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff82706085>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:510
Kernel Offset: disabled
Rebooting in 86400 seconds..