IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: 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: [<ffffffff835aab88>] sock_hold include/net/sock.h:589 [inline]
IP: [<ffffffff835aab88>] l2tp_session_create+0x948/0x1030 net/l2tp/l2tp_core.c:1809
PGD b4be1067 PUD b4a88067 PMD 0 
Oops: 0002 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 5626 Comm: syz-executor0 Not tainted 4.4.153-g5e24b4e #90
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801cc843000 task.stack: ffff8800b0a78000
RIP: 0010:[<ffffffff835aab88>]  [<ffffffff835aab88>] sock_hold include/net/sock.h:589 [inline]
RIP: 0010:[<ffffffff835aab88>]  [<ffffffff835aab88>] l2tp_session_create+0x948/0x1030 net/l2tp/l2tp_core.c:1809
RSP: 0018:ffff8800b0a7fb48  EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8800b4ad0780 RCX: 0000000000000006
RDX: 1ffff1001695a120 RSI: ffffffff835a4c93 RDI: ffff8800b4ad0900
RBP: ffff8800b0a7fbb8 R08: 000000000000000a R09: 000000000000ffff
R10: ffffed0039a3df38 R11: ffffffff8463a200 R12: ffff8801cd1ef9a8
R13: ffff8800b0a7fcd0 R14: ffff8801cd1ef900 R15: ffffffff835a38c0
FS:  00007f5dd4090700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000080 CR3: 00000000b1cb2000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff81140aba ffff8800b4ad07a0 ffff8801cd1efa58 ffff8801cd1ef910
 ffffffff838cc1e0 ffff8801cd1ef9b0 ffff8801cd1efa50 ffff8800b4ad0860
 ffffffff00000000 ffff8800b42f1980 0000000000000000 ffff8800b42f19b0
Call Trace:
 [<ffffffff835aef80>] pppol2tp_connect+0x10f0/0x1910 net/l2tp/l2tp_ppp.c:725
 [<ffffffff82f27ef8>] SYSC_connect+0x1b8/0x300 net/socket.c:1570
 [<ffffffff82f2a844>] SyS_connect+0x24/0x30 net/socket.c:1551
 [<ffffffff838cc865>] entry_SYSCALL_64_fastpath+0x22/0x9e
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  [<ffffffff835aab88>] sock_hold include/net/sock.h:589 [inline]
RIP  [<ffffffff835aab88>] l2tp_session_create+0x948/0x1030 net/l2tp/l2tp_core.c:1809
 RSP <ffff8800b0a7fb48>
CR2: 0000000000000080
---[ end trace 138bf6d445bee133 ]---