kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 7839 Comm: syz-executor2 Not tainted 4.15.0-rc9+ #282
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__lock_acquire+0xa09/0x3e00 kernel/locking/lockdep.c:3305
RSP: 0018:ffff8801bd677450 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000014 RSI: 0000000000000000 RDI: ffffffff868c8c60
RBP: ffff8801bd6777e0 R08: ffffffff84304704 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000000000a0 R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffff8801bc9b6340
FS:  00007fbcb652d700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020e71000 CR3: 00000001d913c002 CR4: 00000000001626e0
Call Trace:
 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168
 spin_lock_bh include/linux/spinlock.h:315 [inline]
 lock_sock_nested+0x44/0x110 net/core/sock.c:2762
 lock_sock include/net/sock.h:1461 [inline]
 inet_shutdown+0x62/0x350 net/ipv4/af_inet.c:816
 pppol2tp_session_close+0x92/0xf0 net/l2tp/l2tp_ppp.c:430
 l2tp_tunnel_closeall+0x305/0x410 net/l2tp/l2tp_core.c:1294
 l2tp_udp_encap_destroy+0x95/0x100 net/l2tp/l2tp_core.c:1317
 udpv6_destroy_sock+0x161/0x190 net/ipv6/udp.c:1437
 sk_common_release+0x6b/0x2f0 net/core/sock.c:2989
 udp_lib_close+0x15/0x20 include/net/udp.h:203
 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:426
 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:432
 sock_release+0x8d/0x1e0 net/socket.c:602
 sock_close+0x16/0x20 net/socket.c:1131
 __fput+0x327/0x7e0 fs/file_table.c:210
 ____fput+0x15/0x20 fs/file_table.c:244
 task_work_run+0x199/0x270 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x296/0x310 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264
 entry_SYSCALL_64_fastpath+0x9e/0xa0
RIP: 0033:0x452f19
RSP: 002b:00007fbcb652cc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 000000000071bea0 RCX: 0000000000452f19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000013
RBP: 0000000000000052 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006ef850
R13: 00000000ffffffff R14: 00007fbcb652d6d4 R15: 0000000000000000
Code: 81 c4 60 03 00 00 44 89 d0 5b 41 5a 41 5c 41 5d 41 5e 41 5f 5d 49 8d 62 f8 c3 4c 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 0a 33 00 00 49 81 3b e0 2c 33 87 41 bd 00 00 
RIP: __lock_acquire+0xa09/0x3e00 kernel/locking/lockdep.c:3305 RSP: ffff8801bd677450
---[ end trace c8f229d0de7ed68a ]---