kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 10259 Comm: syz-executor0 Not tainted 4.9.80-g8a174b47 #31
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801b29b3000 task.stack: ffff8801d6888000
RIP: 0010:[<ffffffff8123c8fc>]  [<ffffffff8123c8fc>] __lock_acquire+0x9fc/0x3640 kernel/locking/lockdep.c:3224
RSP: 0018:ffff8801d688f9c0  EFLAGS: 00010006
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000014 RSI: 0000000000000000 RDI: 00000000000000a0
RBP: ffff8801d688fb80 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: ffff8801b29b3000 R12: 0000000000000001
R13: 0000000000000001 R14: 0000000000000000 R15: 00000000000000a0
FS:  00007f8c01225700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000401cc0 CR3: 00000001d7a46000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801d688fb90 0000000000000046 000000000000049e 0000000000000004
 0000000000000000 0000000000000000 ffff8801d688fbc0 0000000000000046
 0000000000000046 ffffffff812e0ad2 ffff8801b29b3000 ffff8801b29b38b0
Call Trace:
 [<ffffffff8123ff7e>] lock_acquire+0x12e/0x410 kernel/locking/lockdep.c:3756
 [<ffffffff838b29fa>] __raw_spin_lock_bh include/linux/spinlock_api_smp.h:137 [inline]
 [<ffffffff838b29fa>] _raw_spin_lock_bh+0x3a/0x50 kernel/locking/spinlock.c:175
 [<ffffffff82ee3ff3>] spin_lock_bh include/linux/spinlock.h:307 [inline]
 [<ffffffff82ee3ff3>] lock_sock_nested+0x43/0x120 net/core/sock.c:2503
 [<ffffffff832e8852>] lock_sock include/net/sock.h:1404 [inline]
 [<ffffffff832e8852>] inet_shutdown+0x62/0x350 net/ipv4/af_inet.c:823
 [<ffffffff83589f40>] pppol2tp_session_close+0xa0/0xe0 net/l2tp/l2tp_ppp.c:441
 [<ffffffff8358493f>] l2tp_tunnel_closeall+0x21f/0x3a0 net/l2tp/l2tp_core.c:1368
 [<ffffffff83585547>] l2tp_udp_encap_destroy+0x87/0xe0 net/l2tp/l2tp_core.c:1394
 [<ffffffff8348b2a1>] udpv6_destroy_sock+0xb1/0xd0 net/ipv6/udp.c:1336
 [<ffffffff82eeb5ab>] sk_common_release+0x6b/0x2f0 net/core/sock.c:2727
 [<ffffffff8348a255>] udp_lib_close+0x15/0x20 include/net/udp.h:203
 [<ffffffff832e8c3a>] inet_release+0xfa/0x1d0 net/ipv4/af_inet.c:434
 [<ffffffff8340f790>] inet6_release+0x50/0x70 net/ipv6/af_inet6.c:437
 [<ffffffff82ed489d>] sock_release+0x8d/0x1e0 net/socket.c:599
 [<ffffffff82ed4a06>] sock_close+0x16/0x20 net/socket.c:1046
 [<ffffffff8157570c>] __fput+0x28c/0x6e0 fs/file_table.c:208
 [<ffffffff81575be5>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff811957d5>] task_work_run+0x115/0x190 kernel/task_work.c:116
 [<ffffffff81003a4c>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff81003a4c>] exit_to_usermode_loop+0xfc/0x120 arch/x86/entry/common.c:160
 [<ffffffff81006340>] prepare_exit_to_usermode arch/x86/entry/common.c:190 [inline]
 [<ffffffff81006340>] syscall_return_slowpath+0x1a0/0x1e0 arch/x86/entry/common.c:259
 [<ffffffff838b35ab>] entry_SYSCALL_64_fastpath+0xe6/0xe8
Code: 25 28 00 00 00 0f 85 a4 21 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c9 24 00 00 49 81 3f a0 9d c6 84 41 bd 00 00 
RIP  [<ffffffff8123c8fc>] __lock_acquire+0x9fc/0x3640 kernel/locking/lockdep.c:3224
 RSP <ffff8801d688f9c0>
---[ end trace 4e556a71a0fdf4a9 ]---