IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
------------[ cut here ]------------
WARNING: CPU: 1 PID: 2359 at net/ipv4/af_inet.c:167 inet_sock_destruct+0x598/0x760 net/ipv4/af_inet.c:167
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 2359 Comm: udevd Not tainted 4.9.117-g8b21e85 #23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801db307cc0 ffffffff81eb4be9 ffffffff83c48980 00000000ffffffff
 0000000000000000 0000000000000001 00000000000000a7 ffff8801db307d80
 ffffffff81421c85 0000000041b58ab3 ffffffff843bc020 ffffffff81421ac6
Call Trace:
 <IRQ> [   34.967211]  [<ffffffff81eb4be9>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ> [   34.967211]  [<ffffffff81eb4be9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81421c85>] panic+0x1bf/0x3bc kernel/panic.c:179
 [<ffffffff81421f71>] __warn.cold.9+0xc1/0x17f kernel/panic.c:542
 [<ffffffff8113683c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
 [<ffffffff83427628>] inet_sock_destruct+0x598/0x760 net/ipv4/af_inet.c:167
 [<ffffffff836c0a19>] l2tp_tunnel_destruct+0x339/0x590 net/l2tp/l2tp_core.c:1329
 [<ffffffff83023095>] __sk_destruct+0x55/0x590 net/core/sock.c:1428
 [<ffffffff8128780e>] __rcu_reclaim kernel/rcu/rcu.h:118 [inline]
 [<ffffffff8128780e>] rcu_do_batch kernel/rcu/tree.c:2789 [inline]
 [<ffffffff8128780e>] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline]
 [<ffffffff8128780e>] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline]
 [<ffffffff8128780e>] rcu_process_callbacks+0x8ae/0x12b0 kernel/rcu/tree.c:3037
 [<ffffffff83a037fb>] __do_softirq+0x20b/0x937 kernel/softirq.c:284
 [<ffffffff8114b277>] invoke_softirq kernel/softirq.c:364 [inline]
 [<ffffffff8114b277>] irq_exit+0x147/0x190 kernel/softirq.c:405
 [<ffffffff83a023e1>] exiting_irq arch/x86/include/asm/apic.h:659 [inline]
 [<ffffffff83a023e1>] smp_apic_timer_interrupt+0x81/0xa0 arch/x86/kernel/apic/apic.c:960
 [<ffffffff839fe570>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:648
 <EOI> [   35.095416]  [<ffffffff839fc30f>] ? arch_local_irq_restore arch/x86/include/asm/paravirt.h:768 [inline]
 <EOI> [   35.095416]  [<ffffffff839fc30f>] ? __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:162 [inline]
 <EOI> [   35.095416]  [<ffffffff839fc30f>] ? _raw_spin_unlock_irqrestore+0x5f/0x70 kernel/locking/spinlock.c:191
 [<ffffffff8122089b>] spin_unlock_irqrestore include/linux/spinlock.h:362 [inline]
 [<ffffffff8122089b>] __wake_up_sync_key+0x4b/0x60 kernel/sched/wait.c:146
 [<ffffffff83028e40>] sock_def_readable+0x100/0x400 net/core/sock.c:2374
 [<ffffffff83548fd2>] unix_dgram_sendmsg+0xb82/0x10e0 net/unix/af_unix.c:1823
 [<ffffffff83018fcc>] sock_sendmsg_nosec net/socket.c:635 [inline]
 [<ffffffff83018fcc>] sock_sendmsg+0xcc/0x110 net/socket.c:645
 [<ffffffff83019cbc>] SYSC_sendto+0x21c/0x370 net/socket.c:1670
 [<ffffffff8301c2d0>] SyS_sendto+0x40/0x50 net/socket.c:1638
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839fcc13>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..