------------[ cut here ]------------
WARNING: CPU: 1 PID: 21308 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: 21308 Comm: syz-executor0 Not tainted 4.9.119-g92e8704 #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801db307cc0 ffffffff81eb4be9 ffffffff83c48980 00000000ffffffff
 0000000000000000 0000000000000001 00000000000000a7 ffff8801db307d80
 ffffffff81421c95 0000000041b58ab3 ffffffff843bc020 ffffffff81421ad6
Call Trace:
 <IRQ> [  332.883115]  [<ffffffff81eb4be9>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ> [  332.883115]  [<ffffffff81eb4be9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81421c95>] panic+0x1bf/0x3bc kernel/panic.c:179
 [<ffffffff81421f81>] __warn.cold.9+0xc1/0x17f kernel/panic.c:542
 [<ffffffff8113683c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
 [<ffffffff83427758>] inet_sock_destruct+0x598/0x760 net/ipv4/af_inet.c:167
 [<ffffffff836c0ac9>] l2tp_tunnel_destruct+0x339/0x590 net/l2tp/l2tp_core.c:1329
 [<ffffffff830230f5>] __sk_destruct+0x55/0x590 net/core/sock.c:1428
 [<ffffffff812877ce>] __rcu_reclaim kernel/rcu/rcu.h:118 [inline]
 [<ffffffff812877ce>] rcu_do_batch kernel/rcu/tree.c:2789 [inline]
 [<ffffffff812877ce>] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline]
 [<ffffffff812877ce>] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline]
 [<ffffffff812877ce>] rcu_process_callbacks+0x8ae/0x12b0 kernel/rcu/tree.c:3037
 [<ffffffff83a038bb>] __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
 [<ffffffff83a024a1>] exiting_irq arch/x86/include/asm/apic.h:659 [inline]
 [<ffffffff83a024a1>] smp_apic_timer_interrupt+0x81/0xa0 arch/x86/kernel/apic/apic.c:960
 [<ffffffff839fe630>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:648
 <EOI> [  333.005221]  [<ffffffff814c832e>] ? __read_once_size include/linux/compiler.h:243 [inline]
 <EOI> [  333.005221]  [<ffffffff814c832e>] ? compound_head include/linux/page-flags.h:143 [inline]
 <EOI> [  333.005221]  [<ffffffff814c832e>] ? PageAnon include/linux/page-flags.h:386 [inline]
 <EOI> [  333.005221]  [<ffffffff814c832e>] ? zap_pte_range mm/memory.c:1155 [inline]
 <EOI> [  333.005221]  [<ffffffff814c832e>] ? zap_pmd_range mm/memory.c:1258 [inline]
 <EOI> [  333.005221]  [<ffffffff814c832e>] ? zap_pud_range mm/memory.c:1279 [inline]
 <EOI> [  333.005221]  [<ffffffff814c832e>] ? unmap_page_range+0xbbe/0x1730 mm/memory.c:1300
 [<ffffffff814c8fa1>] unmap_single_vma+0x101/0x260 mm/memory.c:1345
 [<ffffffff814c98e2>] unmap_vmas+0x102/0x1d0 mm/memory.c:1375
 [<ffffffff814e2044>] exit_mmap+0x214/0x3f0 mm/mmap.c:3020
 [<ffffffff8112bfe3>] __mmput kernel/fork.c:884 [inline]
 [<ffffffff8112bfe3>] mmput+0xf3/0x2d0 kernel/fork.c:906
 [<ffffffff81140dd6>] exit_mm kernel/exit.c:514 [inline]
 [<ffffffff81140dd6>] do_exit+0x906/0x27b0 kernel/exit.c:820
 [<ffffffff81146f91>] do_group_exit+0x111/0x340 kernel/exit.c:937
 [<ffffffff81169def>] 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
 [<ffffffff81007073>] prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline]
 [<ffffffff81007073>] syscall_return_slowpath arch/x86/entry/common.c:260 [inline]
 [<ffffffff81007073>] do_syscall_32_irqs_on arch/x86/entry/common.c:331 [inline]
 [<ffffffff81007073>] do_fast_syscall_32+0x5c3/0x870 arch/x86/entry/common.c:387
 [<ffffffff839fe3d0>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..