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: 8187 Comm: syz-executor1 Not tainted 4.15.0+ #209
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:ip6_xmit+0xc16/0x2260 net/ipv6/ip6_output.c:264
RSP: 0018:ffff8801d41873e8 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff8801d954f680 RCX: ffffffff84c3f8ad
RDX: 000000001fffc05a RSI: ffffc90001fb3000 RDI: 00000000fffe02d0
RBP: ffff8801d4187658 R08: 1ffff1003b2a9e01 R09: ffff8801d41875a8
R10: ffff8801d41873e8 R11: ffffed003a830ebc R12: 00000000fffe0000
R13: ffffed003a830eb5 R14: 0000000000000040 R15: ffff8801cbdbf7a4
FS:  0000000000000000(0000) GS:ffff8801db500000(0063) knlGS:00000000f774fb40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000020e77000 CR3: 00000001a5873006 CR4: 00000000001606e0
Call Trace:
 inet6_csk_xmit+0x2fc/0x580 net/ipv6/inet6_connection_sock.c:139
 l2tp_xmit_core net/l2tp/l2tp_core.c:1096 [inline]
 l2tp_xmit_skb+0x105f/0x1410 net/l2tp/l2tp_core.c:1191
 pppol2tp_sendmsg+0x470/0x670 net/l2tp/l2tp_ppp.c:341
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:640
 ___sys_sendmsg+0x767/0x8b0 net/socket.c:2046
 __sys_sendmsg+0xe5/0x210 net/socket.c:2080
 C_SYSC_sendmsg net/compat.c:739 [inline]
 compat_SyS_sendmsg+0x2a/0x40 net/compat.c:737
 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline]
 do_fast_syscall_32+0x3ee/0xfa1 arch/x86/entry/common.c:392
 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:129
RIP: 0023:0xf7f53c79
RSP: 002b:00000000f774f08c EFLAGS: 00000296 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000015 RCX: 0000000020e85fe4
RDX: 0000000000000081 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Code: 4d 8b a4 24 18 01 00 00 4d 85 e4 74 67 e8 03 ae ac 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 5b 13 00 00 48 8b 95 e0 fd ff ff 48 b8 00 00 
RIP: ip6_xmit+0xc16/0x2260 net/ipv6/ip6_output.c:264 RSP: ffff8801d41873e8
---[ end trace 4af7dd7ed07cdc5f ]---
Kernel panic - not syncing: Fatal exception in interrupt
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..