IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
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
BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
IP: [<ffffffff836c7e40>] sock_hold include/net/sock.h:584 [inline]
IP: [<ffffffff836c7e40>] l2tp_session_create+0xc60/0x16f0 net/l2tp/l2tp_core.c:1911
PGD 1d868f067 [   47.754345] PUD 1d46dc067 
Oops: 0002 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 4282 Comm: syz-executor0 Not tainted 4.9.122-g54068d6 #78
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d45e9800 task.stack: ffff8801d4bc0000
RIP: 0010:[<ffffffff836c7e40>]  [<ffffffff836c7e40>] sock_hold include/net/sock.h:584 [inline]
RIP: 0010:[<ffffffff836c7e40>]  [<ffffffff836c7e40>] l2tp_session_create+0xc60/0x16f0 net/l2tp/l2tp_core.c:1911
RSP: 0018:ffff8801d4bc7ac0  EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8801d6dfec80 RCX: 1ffff1003a8bd41d
RDX: 1ffff1003adbfcd0 RSI: ffff8801d45ea0c8 RDI: ffff8801d6dfe680
RBP: ffff8801d4bc7b60 R08: ffff8801d45ea0e8 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d6dfe558
R13: 0000000000000000 R14: ffff8801d6dfe500 R15: 0000000000000000
FS:  00007f887f681700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000080 CR3: 00000001d4907000 CR4: 00000000001606f0
Stack:
 ffffffff836c80b7 ffffffff836c9151 ffff8801d3b54c48 0000000000000000
 ffff8801d6dfe500 ffff8801d6dfedd8 ffff8801d6dfe558 ffff8801d6dfedd0
 ffff8801d6dfed30 ffff8801d6dfe520 ffff8801d3b54400 0000000000000000
Call Trace:
 [<ffffffff836ccff7>] pppol2tp_connect+0x10d7/0x18f0 net/l2tp/l2tp_ppp.c:718
 [<ffffffff8301d958>] SYSC_connect+0x1b8/0x300 net/socket.c:1563
 [<ffffffff83020224>] SyS_connect+0x24/0x30 net/socket.c:1544
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff83a00cd3>] 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  [<ffffffff836c7e40>] sock_hold include/net/sock.h:584 [inline]
RIP  [<ffffffff836c7e40>] l2tp_session_create+0xc60/0x16f0 net/l2tp/l2tp_core.c:1911
 RSP <ffff8801d4bc7ac0>
CR2: 0000000000000080
---[ end trace 49befb2320891f12 ]---