IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready
ip (3905) used greatest stack depth: 24432 bytes left
IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
IP: [<ffffffff835aa528>] sock_hold include/net/sock.h:589 [inline]
IP: [<ffffffff835aa528>] l2tp_session_create+0x948/0x1030 net/l2tp/l2tp_core.c:1809
PGD 1ca913067 PUD 1d8194067 PMD 0 
Oops: 0002 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 4158 Comm: syz-executor0 Not tainted 4.4.151-g3a2ec58 #22
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800b995b000 task.stack: ffff8801d81e8000
RIP: 0010:[<ffffffff835aa528>]  [<ffffffff835aa528>] sock_hold include/net/sock.h:589 [inline]
RIP: 0010:[<ffffffff835aa528>]  [<ffffffff835aa528>] l2tp_session_create+0x948/0x1030 net/l2tp/l2tp_core.c:1809
RSP: 0018:ffff8801d81efad0  EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8800afebc000 RCX: 0000000000000006
RDX: 1ffff10015fd7830 RSI: ffffffff835a4633 RDI: ffff8800afebc180
RBP: ffff8801d81efb40 R08: ffff8800b995b900 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8463a140 R12: ffff8801d8282328
R13: ffff8801d81efc58 R14: ffff8801d8282280 R15: ffffffff835a3260
FS:  0000000000000000(0000) GS:ffff8801db200000(0063) knlGS:00000000f770db40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000000080 CR3: 00000001d8309000 CR4: 00000000001606f0
Stack:
 ffffffff81140a6a ffff8800afebc020 ffff8801d82823d8 ffff8801d8282290
 ffffffff838cbb80 ffff8801d8282330 ffff8801d82823d0 ffff8800afebc0e0
 ffffffff00000000 ffff8801d7963300 0000000000000000 ffff8801d7963330
Call Trace:
 [<ffffffff835ae920>] pppol2tp_connect+0x10f0/0x1910 net/l2tp/l2tp_ppp.c:725
 [<ffffffff82f27838>] SYSC_connect+0x1b8/0x300 net/socket.c:1570
 [<ffffffff82f2a184>] SyS_connect+0x24/0x30 net/socket.c:1551
 [<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
 [<ffffffff838cdb83>] 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  [<ffffffff835aa528>] sock_hold include/net/sock.h:589 [inline]
RIP  [<ffffffff835aa528>] l2tp_session_create+0x948/0x1030 net/l2tp/l2tp_core.c:1809
 RSP <ffff8801d81efad0>
CR2: 0000000000000080
---[ end trace c55c6bbbf34519c4 ]---