------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 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: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.95-gee0bcd6 #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801db207cc0 ffffffff81eb0f89 ffffffff83a484a0 00000000ffffffff
 0000000000000000 0000000000000000 00000000000000a7 ffff8801db207d80
 ffffffff8141f945 0000000041b58ab3 ffffffff841b7cf8 ffffffff8141f786
Call Trace:
 <IRQ> [   26.877637]  [<ffffffff81eb0f89>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ> [   26.877637]  [<ffffffff81eb0f89>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8141f945>] panic+0x1bf/0x3bc kernel/panic.c:179
 [<ffffffff8141fc31>] __warn.cold.9+0xc1/0x17f kernel/panic.c:542
 [<ffffffff8113461c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
 [<ffffffff8341dc28>] inet_sock_destruct+0x598/0x760 net/ipv4/af_inet.c:167
 [<ffffffff836b6439>] l2tp_tunnel_destruct+0x339/0x590 net/l2tp/l2tp_core.c:1329
 [<ffffffff8301b095>] __sk_destruct+0x55/0x590 net/core/sock.c:1428
 [<ffffffff8128575e>] __rcu_reclaim kernel/rcu/rcu.h:118 [inline]
 [<ffffffff8128575e>] rcu_do_batch kernel/rcu/tree.c:2789 [inline]
 [<ffffffff8128575e>] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline]
 [<ffffffff8128575e>] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline]
 [<ffffffff8128575e>] rcu_process_callbacks+0x8ae/0x12b0 kernel/rcu/tree.c:3037
 [<ffffffff839f8efb>] __do_softirq+0x20b/0x937 kernel/softirq.c:284
 [<ffffffff81149037>] invoke_softirq kernel/softirq.c:364 [inline]
 [<ffffffff81149037>] irq_exit+0x147/0x190 kernel/softirq.c:405
 [<ffffffff839f7ae1>] exiting_irq arch/x86/include/asm/apic.h:659 [inline]
 [<ffffffff839f7ae1>] smp_apic_timer_interrupt+0x81/0xa0 arch/x86/kernel/apic/apic.c:960
 [<ffffffff839f3c70>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:648
 <EOI> [   27.005962]  [<ffffffff839f0f16>] ? native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:53
 [<ffffffff839f0555>] arch_safe_halt arch/x86/include/asm/paravirt.h:104 [inline]
 [<ffffffff839f0555>] default_idle+0x55/0x360 arch/x86/kernel/process.c:295
 [<ffffffff81069fa0>] arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:286
 [<ffffffff839f1375>] default_idle_call+0x45/0x60 kernel/sched/idle.c:97
 [<ffffffff81220e35>] cpuidle_idle_call kernel/sched/idle.c:155 [inline]
 [<ffffffff81220e35>] cpu_idle_loop kernel/sched/idle.c:248 [inline]
 [<ffffffff81220e35>] cpu_startup_entry+0x2b5/0x380 kernel/sched/idle.c:303
 [<ffffffff839de1dc>] rest_init+0x183/0x189 init/main.c:409
 [<ffffffff84a96943>] start_kernel+0x67e/0x6b2 init/main.c:664
 [<ffffffff84a9529a>] x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:196
 [<ffffffff84a953db>] x86_64_start_kernel+0x13f/0x162 arch/x86/kernel/head64.c:177
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..