IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
hrtimer: interrupt took 17531 ns
l2tp_core: tunl 4: sockfd_lookup(fd=6) returned -9
BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
IP: [<ffffffff836c8e30>] sock_hold include/net/sock.h:584 [inline]
IP: [<ffffffff836c8e30>] l2tp_session_create+0xc60/0x16f0 net/l2tp/l2tp_core.c:1911
PGD 1d49c1067 [   42.088390] PUD 1da3d7067 
Oops: 0002 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 4275 Comm: syz-executor0 Not tainted 4.9.123-g8dd3fc2 #79
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d484c800 task.stack: ffff8801d4bb8000
RIP: 0010:[<ffffffff836c8e30>]  [<ffffffff836c8e30>] sock_hold include/net/sock.h:584 [inline]
RIP: 0010:[<ffffffff836c8e30>]  [<ffffffff836c8e30>] l2tp_session_create+0xc60/0x16f0 net/l2tp/l2tp_core.c:1911
RSP: 0018:ffff8801d4bbfac0  EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8801d44f5400 RCX: 1ffff1003a909a1d
RDX: 1ffff1003a933880 RSI: ffff8801d484d0c8 RDI: ffff8801d499c400
RBP: ffff8801d4bbfb60 R08: ffff8801d484d0e8 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d499c2d8
R13: 0000000000000000 R14: ffff8801d499c280 R15: ffff8801d4bbfc78
FS:  00007f95513ca700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000080 CR3: 00000001da0b7000 CR4: 00000000001606f0
Stack:
 0000000000000201 ffffffff836ca141 ffff8801d4bbfae0 ffffffff81237f0d
 ffff8801d499c280 ffff8801d44f5558 ffff8801d499c2d8 ffff8801d44f5550
 ffff8801d44f54b0 ffff8801d499c2a0 0000000000000000 0000000000000000
Call Trace:
 [<ffffffff836cdfe7>] pppol2tp_connect+0x10d7/0x18f0 net/l2tp/l2tp_ppp.c:718
 [<ffffffff8301e958>] SYSC_connect+0x1b8/0x300 net/socket.c:1563
 [<ffffffff83021224>] SyS_connect+0x24/0x30 net/socket.c:1544
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff83a01c93>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 00 00 49 8d be 80 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 7b 09 00 00 49 8b 86 80 01 00 00 <f0> ff 80 80 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 55 d0 
RIP  [<ffffffff836c8e30>] sock_hold include/net/sock.h:584 [inline]
RIP  [<ffffffff836c8e30>] l2tp_session_create+0xc60/0x16f0 net/l2tp/l2tp_core.c:1911
 RSP <ffff8801d4bbfac0>
CR2: 0000000000000080
---[ end trace d2492245c40d3f50 ]---