IPv6: ADDRCONF(NETDEV_CHANGE): veth0: 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: [<ffffffff836c8bb0>] sock_hold include/net/sock.h:584 [inline]
IP: [<ffffffff836c8bb0>] l2tp_session_create+0xc60/0x16f0 net/l2tp/l2tp_core.c:1911
PGD 1be1da067 [   35.488785] PUD 1be2ba067 
Oops: 0002 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 6890 Comm: syz-executor7 Not tainted 4.9.124-g09eb2ba #35
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801cb6f1800 task.stack: ffff8801cf260000
RIP: 0010:[<ffffffff836c8bb0>]  [<ffffffff836c8bb0>] sock_hold include/net/sock.h:584 [inline]
RIP: 0010:[<ffffffff836c8bb0>]  [<ffffffff836c8bb0>] l2tp_session_create+0xc60/0x16f0 net/l2tp/l2tp_core.c:1911
RSP: 0018:ffff8801cf267ab0  EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8801d30dcf00 RCX: 1ffff100396de41d
RDX: 1ffff10037a12ab0 RSI: ffff8801cb6f20c8 RDI: ffff8801bd095580
RBP: ffff8801cf267b50 R08: ffff8801cb6f20e8 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801bd095458
R13: 0000000000000000 R14: ffff8801bd095400 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801db200000(0063) knlGS:00000000f777db40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000000080 CR3: 00000001d7b85000 CR4: 00000000001606f0
Stack:
 ffffffff836c8e27 ffffffff836c9ec1 ffff8801bad8ee48 0000000000000000
 ffff8801bd095400 ffff8801d30dd058 ffff8801bd095458 ffff8801d30dd050
 ffff8801d30dcfb0 ffff8801bd095420 ffff8801bad8e600 0000000000000000
Call Trace:
 [<ffffffff836cdd67>] pppol2tp_connect+0x10d7/0x18f0 net/l2tp/l2tp_ppp.c:718
 [<ffffffff8301ea38>] SYSC_connect+0x1b8/0x300 net/socket.c:1575
 [<ffffffff83021314>] SyS_connect+0x24/0x30 net/socket.c:1556
 [<ffffffff81006da7>] do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
 [<ffffffff81006da7>] do_fast_syscall_32+0x2f7/0x870 arch/x86/entry/common.c:387
 [<ffffffff83a030d0>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137
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  [<ffffffff836c8bb0>] sock_hold include/net/sock.h:584 [inline]
RIP  [<ffffffff836c8bb0>] l2tp_session_create+0xc60/0x16f0 net/l2tp/l2tp_core.c:1911
 RSP <ffff8801cf267ab0>
CR2: 0000000000000080
---[ end trace effa57cbcd59bb5c ]---