l2tp_core: tunl 4: sockfd_lookup(fd=6) returned -9
l2tp_core: tunl 4: sockfd_lookup(fd=5) returned -9
------------[ cut here ]------------
WARNING: CPU: 1 PID: 9629 at kernel/locking/lockdep.c:722 arch_local_save_flags arch/x86/include/asm/paravirt.h:774 [inline]
WARNING: CPU: 1 PID: 9629 at kernel/locking/lockdep.c:722 look_up_lock_class kernel/locking/lockdep.c:713 [inline]
WARNING: CPU: 1 PID: 9629 at kernel/locking/lockdep.c:722 register_lock_class+0xfb6/0x1cd0 kernel/locking/lockdep.c:756
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 9629 Comm: syz-executor.3 Not tainted 4.14.176-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xf7/0x13b lib/dump_stack.c:58
 panic+0x1b0/0x358 kernel/panic.c:183
 __warn.cold.8+0x25/0x2c kernel/panic.c:547
 report_bug+0x1a4/0x1f3 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 do_error_trap+0x1bd/0x310 arch/x86/kernel/traps.c:295
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963
RIP: 0010:look_up_lock_class kernel/locking/lockdep.c:722 [inline]
RIP: 0010:register_lock_class+0xfb6/0x1cd0 kernel/locking/lockdep.c:756
RSP: 0018:ffff8880907f7590 EFLAGS: 00010083
RAX: dffffc0000000000 RBX: ffffffff88f0a610 RCX: 1ffff110120feebd
RDX: 1ffff110134c9237 RSI: 0000000000000000 RDI: ffff88809a6491b8
RBP: ffff8880907f7670 R08: ffff88809a6491a0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89381800
R13: 1ffff110120feebd R14: ffffffff870dbd00 R15: ffffffff88f0a610
 __lock_acquire+0x14f/0x4500 kernel/locking/lockdep.c:3374
 lock_acquire+0x173/0x400 kernel/locking/lockdep.c:3994
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:176
 spin_lock_bh include/linux/spinlock.h:322 [inline]
 lock_sock_nested+0x3a/0x100 net/core/sock.c:2765
 lock_sock include/net/sock.h:1467 [inline]
 do_ipv6_setsockopt.isra.8+0x2e0/0x32c0 net/ipv6/ipv6_sockglue.c:167
 ipv6_setsockopt+0x6e/0xf0 net/ipv6/ipv6_sockglue.c:931
 udpv6_setsockopt+0x16/0x30 net/ipv6/udp.c:1459
 sock_common_setsockopt+0x73/0xf0 net/core/sock.c:2971
 SYSC_setsockopt net/socket.c:1865 [inline]
 SyS_setsockopt+0x130/0x1f0 net/socket.c:1844
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x459829
RSP: 002b:00007f546ae2ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459829
RDX: 0000000000000023 RSI: 0000000000000029 RDI: 0000000000000005
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f546ae2b6d4
R13: 00000000004ced30 R14: 00000000004dd678 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..