kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 2172 Comm: syz-executor4 Not tainted 4.16.0-rc4+ #266
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:ip6_xmit+0xc1f/0x2260 net/ipv6/ip6_output.c:264
RSP: 0018:ffff8801d49b7438 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff8801cdfb2480 RCX: ffffffff84ef6076
RDX: 000000001fffbe3a RSI: ffffc90003e53000 RDI: 00000000fffdf1d0
RBP: ffff8801d49b76a8 R08: 1ffff10039bf6401 R09: ffff8801d49b75f8
R10: ffff8801d49b7438 R11: ffffed003a936ec6 R12: 00000000fffdef00
R13: ffffed003a936ebf R14: 0000000000000040 R15: ffff8801d4805b64
FS:  00007f32076d0700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002037ffc8 CR3: 00000001a9456001 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 inet6_csk_xmit+0x2fc/0x580 net/ipv6/inet6_connection_sock.c:139
 l2tp_xmit_core net/l2tp/l2tp_core.c:1053 [inline]
 l2tp_xmit_skb+0x105f/0x1410 net/l2tp/l2tp_core.c:1148
 pppol2tp_sendmsg+0x470/0x670 net/l2tp/l2tp_ppp.c:341
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:639
 ___sys_sendmsg+0x767/0x8b0 net/socket.c:2047
 __sys_sendmsg+0xe5/0x210 net/socket.c:2081
 SYSC_sendmsg net/socket.c:2092 [inline]
 SyS_sendmsg+0x2d/0x50 net/socket.c:2088
 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x453e69
RSP: 002b:00007f32076cfc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f32076d06d4 RCX: 0000000000453e69
RDX: 0000000000000081 RSI: 000000002037ffc8 RDI: 0000000000000016
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000004c3 R14: 00000000006f72e8 R15: 0000000000000000
Code: 4d 8b a4 24 18 01 00 00 4d 85 e4 74 67 e8 6a a9 81 fc 49 8d bc 24 d0 02 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 52 13 00 00 48 8b 95 e0 fd ff ff 48 b8 00 00 
RIP: ip6_xmit+0xc1f/0x2260 net/ipv6/ip6_output.c:264 RSP: ffff8801d49b7438
---[ end trace 81c71dd495d724e9 ]---
Kernel panic - not syncing: Fatal exception in interrupt
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..