------------[ cut here ]------------ WARNING: CPU: 1 PID: 17 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: 17 Comm: ksoftirqd/1 Not tainted 4.9.123-g8dd3fc2 #31 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801d9abfa48 ffffffff81eb9689 ffffffff83c48ac0 00000000ffffffff 0000000000000000 0000000000000001 00000000000000a7 ffff8801d9abfb08 ffffffff81423f75 0000000041b58ab3 ffffffff843bb878 ffffffff81423db6 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] panic+0x1bf/0x3bc kernel/panic.c:179 [] __warn.cold.9+0xc1/0x17f kernel/panic.c:542 [] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585 [] inet_sock_destruct+0x598/0x760 net/ipv4/af_inet.c:167 [] l2tp_tunnel_destruct+0x339/0x590 net/l2tp/l2tp_core.c:1329 [] __sk_destruct+0x55/0x590 net/core/sock.c:1428 [] __rcu_reclaim kernel/rcu/rcu.h:118 [inline] [] rcu_do_batch kernel/rcu/tree.c:2789 [inline] [] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline] [] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline] [] rcu_process_callbacks+0x8ae/0x12b0 kernel/rcu/tree.c:3037 [] __do_softirq+0x210/0x940 kernel/softirq.c:288 [] run_ksoftirqd+0x30/0x60 kernel/softirq.c:680 [] smpboot_thread_fn+0x5c9/0x900 kernel/smpboot.c:163 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..