------------[ cut here ]------------
WARNING: CPU: 1 PID: 16288 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: 16288 Comm: syz-executor4 Not tainted 4.9.124-g6a1b592 #30
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801db307cc0 ffffffff81eb95e9 ffffffff83c48ac0 00000000ffffffff
 0000000000000000 0000000000000001 00000000000000a7 ffff8801db307d80
 ffffffff81423eb5 0000000041b58ab3 ffffffff843bb8e8 ffffffff81423cf6
Call Trace:
 <IRQ> [  235.605715]  [<ffffffff81eb95e9>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ> [  235.605715]  [<ffffffff81eb95e9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81423eb5>] panic+0x1bf/0x3bc kernel/panic.c:179
 [<ffffffff814241a1>] __warn.cold.9+0xc1/0x17f kernel/panic.c:542
 [<ffffffff811383bc>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
 [<ffffffff8342c878>] inet_sock_destruct+0x598/0x760 net/ipv4/af_inet.c:167
 [<ffffffff836c5839>] l2tp_tunnel_destruct+0x339/0x590 net/l2tp/l2tp_core.c:1329
 [<ffffffff830281f5>] __sk_destruct+0x55/0x590 net/core/sock.c:1428
 [<ffffffff812899ee>] __rcu_reclaim kernel/rcu/rcu.h:118 [inline]
 [<ffffffff812899ee>] rcu_do_batch kernel/rcu/tree.c:2789 [inline]
 [<ffffffff812899ee>] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline]
 [<ffffffff812899ee>] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline]
 [<ffffffff812899ee>] rcu_process_callbacks+0x8ae/0x12b0 kernel/rcu/tree.c:3037
 [<ffffffff83a085c0>] __do_softirq+0x210/0x940 kernel/softirq.c:288
 [<ffffffff8114d554>] invoke_softirq kernel/softirq.c:368 [inline]
 [<ffffffff8114d554>] irq_exit+0x114/0x150 kernel/softirq.c:409
 [<ffffffff83a071a1>] exiting_irq arch/x86/include/asm/apic.h:669 [inline]
 [<ffffffff83a071a1>] smp_apic_timer_interrupt+0x81/0xa0 arch/x86/kernel/apic/apic.c:962
 [<ffffffff83a03330>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:648
 <EOI> [  235.728070]  [<ffffffff8123d7e5>] ? arch_local_irq_restore arch/x86/include/asm/paravirt.h:768 [inline]
 <EOI> [  235.728070]  [<ffffffff8123d7e5>] ? lock_release+0x6a5/0xb80 kernel/locking/lockdep.c:3778
 [<ffffffff815c5aa8>] rcu_lock_release include/linux/rcupdate.h:498 [inline]
 [<ffffffff815c5aa8>] rcu_read_unlock include/linux/rcupdate.h:931 [inline]
 [<ffffffff815c5aa8>] dput.part.29+0x168/0x7b0 fs/dcache.c:797
 [<ffffffff815c610f>] dput+0x1f/0x30 fs/dcache.c:789
 [<ffffffff81595a61>] path_put+0x31/0x70 fs/namei.c:516
 [<ffffffff81621202>] free_fs_struct+0x22/0x60 fs/fs_struct.c:90
 [<ffffffff81622029>] exit_fs+0xe9/0x120 fs/fs_struct.c:108
 [<ffffffff8114314b>] do_exit+0x9bb/0x27b0 kernel/exit.c:829
 [<ffffffff81149251>] do_group_exit+0x111/0x340 kernel/exit.c:937
 [<ffffffff8116c0cf>] get_signal+0x4cf/0x1450 kernel/signal.c:2321
 [<ffffffff81052637>] do_signal+0x87/0x19f0 arch/x86/kernel/signal.c:807
 [<ffffffff81005581>] exit_to_usermode_loop+0xe1/0x120 arch/x86/entry/common.c:157
 [<ffffffff810064d4>] prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline]
 [<ffffffff810064d4>] syscall_return_slowpath arch/x86/entry/common.c:260 [inline]
 [<ffffffff810064d4>] do_syscall_64+0x364/0x490 arch/x86/entry/common.c:287
 [<ffffffff83a019d3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..