bond0 (unregistering): Released all slaves
------------[ cut here ]------------
WARNING: CPU: 1 PID: 6905 at net/xfrm/xfrm_state.c:2336 xfrm_state_fini+0x1f1/0x260 net/xfrm/xfrm_state.c:2336
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 6905 Comm: kworker/u4:5 Not tainted 4.14.141 #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:17 [inline]
 dump_stack+0x138/0x197 lib/dump_stack.c:53
 panic+0x1f2/0x426 kernel/panic.c:182
 __warn.cold+0x2f/0x36 kernel/panic.c:546
 report_bug+0x216/0x254 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x1bb/0x310 arch/x86/kernel/traps.c:295
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963
RIP: 0010:xfrm_state_fini+0x1f1/0x260 net/xfrm/xfrm_state.c:2336
RSP: 0018:ffff88805f53fbe0 EFLAGS: 00010297
RAX: ffff88805f530640 RBX: ffff888081bb0080 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff88805f530f10 RDI: 0000000000000001
RBP: ffff88805f53fbf8 R08: ffff88805f530640 R09: ffff88805f530f30
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888081bb1cc0
R13: ffff88805f53fcf0 R14: ffffffff880b7c38 R15: dffffc0000000000
 xfrm_net_exit+0x25/0x70 net/xfrm/xfrm_policy.c:2857
 ops_exit_list.isra.0+0xaa/0x150 net/core/net_namespace.c:142
 cleanup_net+0x3ba/0x880 net/core/net_namespace.c:484
 process_one_work+0x863/0x1600 kernel/workqueue.c:2114
 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248
 kthread+0x319/0x430 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Kernel Offset: disabled
Rebooting in 86400 seconds..