IPVS: Creating netns size=2536 id=7
IPVS: Creating netns size=2536 id=8
------------[ cut here ]------------
WARNING: CPU: 1 PID: 17 at net/ipv4/af_inet.c:167 inet_sock_destruct+0x5f6/0x7b0 net/ipv4/af_inet.c:167
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 17 Comm: ksoftirqd/1 Not tainted 4.9.77-ge12a9c4 #27
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d9827a40 ffffffff81d941c9 ffffffff83a47bc0 ffff8801d9827b18
 ffffffff83f2f000 ffffffff832ebc36 0000000000000009 ffff8801d9827b08
 ffffffff8142f3c1 0000000041b58ab3 ffffffff8418ab70 ffffffff8142f205
Call Trace:
 [<ffffffff81d941c9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d941c9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8142f3c1>] panic+0x1bc/0x3a8 kernel/panic.c:179
 [<ffffffff81131144>] __warn+0x1c4/0x1e0 kernel/panic.c:542
 [<ffffffff811313ac>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
 [<ffffffff832ebc36>] inet_sock_destruct+0x5f6/0x7b0 net/ipv4/af_inet.c:167
 [<ffffffff835849d2>] l2tp_tunnel_destruct+0x352/0x5a0 net/l2tp/l2tp_core.c:1329
 [<ffffffff82ee5033>] __sk_destruct+0x53/0x570 net/core/sock.c:1428
 [<ffffffff812930f8>] __rcu_reclaim kernel/rcu/rcu.h:118 [inline]
 [<ffffffff812930f8>] rcu_do_batch kernel/rcu/tree.c:2789 [inline]
 [<ffffffff812930f8>] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline]
 [<ffffffff812930f8>] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline]
 [<ffffffff812930f8>] rcu_process_callbacks+0x898/0x1300 kernel/rcu/tree.c:3037
 [<ffffffff838b9846>] __do_softirq+0x206/0x951 kernel/softirq.c:284
 [<ffffffff8114693e>] run_ksoftirqd+0x2e/0x60 kernel/softirq.c:676
 [<ffffffff811a5af1>] smpboot_thread_fn+0x5c1/0x8f0 kernel/smpboot.c:163
 [<ffffffff8119a6fd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b2f69>] ret_from_fork+0x59/0x70 arch/x86/entry/entry_64.S:466
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..