IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
l2tp_core: tunl 4: sockfd_lookup(fd=5) returned -9
BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
IP: [<ffffffff835a8998>] sock_hold include/net/sock.h:589 [inline]
IP: [<ffffffff835a8998>] l2tp_session_create+0x948/0x1030 net/l2tp/l2tp_core.c:1809
PGD b6aec067 PUD b9344067 PMD 0 
Oops: 0002 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 7677 Comm: syz-executor1 Not tainted 4.4.148-gf057ff9 #17
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800b975b000 task.stack: ffff8801d8ed8000
RIP: 0010:[<ffffffff835a8998>]  [<ffffffff835a8998>] sock_hold include/net/sock.h:589 [inline]
RIP: 0010:[<ffffffff835a8998>]  [<ffffffff835a8998>] l2tp_session_create+0x948/0x1030 net/l2tp/l2tp_core.c:1809
RSP: 0018:ffff8801d8edfad0  EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8801d6698280 RCX: 0000000000000000
RDX: 1ffff1003acd3080 RSI: ffffffff835a2a73 RDI: ffff8801d6698400
RBP: ffff8801d8edfb40 R08: ffff8800b975b900 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8463a140 R12: ffff8801d8718fa8
R13: ffff8801d8edfc58 R14: ffff8801d8718f00 R15: ffffffff835a2550
FS:  0000000000000000(0000) GS:ffff8801db200000(0063) knlGS:00000000f7716b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000000080 CR3: 00000000b7b18000 CR4: 00000000001606f0
Stack:
 ffffffff811403aa ffff8801d66982a0 ffff8801d8719058 ffff8801d8718f10
 ffffffff838c9ff0 ffff8801d8718fb0 ffff8801d8719050 ffff8801d6698360
 ffffffff00000000 ffff8801ca4eee80 0000000000000000 ffff8801ca4eeeb0
Call Trace:
 [<ffffffff835acd90>] pppol2tp_connect+0x10f0/0x1910 net/l2tp/l2tp_ppp.c:725
 [<ffffffff82f25cd8>] SYSC_connect+0x1b8/0x300 net/socket.c:1558
 [<ffffffff82f28614>] SyS_connect+0x24/0x30 net/socket.c:1539
 [<ffffffff81006d94>] do_syscall_32_irqs_on arch/x86/entry/common.c:393 [inline]
 [<ffffffff81006d94>] do_fast_syscall_32+0x324/0x8b0 arch/x86/entry/common.c:460
 [<ffffffff838cc003>] sysenter_flags_fixed+0xd/0x1a
Code: 00 00 48 8d bb 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 36 06 00 00 48 8b 83 80 01 00 00 <f0> ff 80 80 00 00 00 48 8d 43 20 48 89 c7 48 89 45 b0 e8 f1 13 
RIP  [<ffffffff835a8998>] sock_hold include/net/sock.h:589 [inline]
RIP  [<ffffffff835a8998>] l2tp_session_create+0x948/0x1030 net/l2tp/l2tp_core.c:1809
 RSP <ffff8801d8edfad0>
CR2: 0000000000000080
---[ end trace 5299910f07524416 ]---