ODEBUG: object ffff8801db207ce8 is NOT on stack ffffffff84600000, but annotated
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 32302 Comm: syz-executor1 Not tainted 4.9.113-g90e7a90 #16
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801ba30c800 task.stack: ffff8801aaab8000
RIP: 0010:[<ffffffff836bd7d5>]  [<ffffffff836bd7d5>] l2tp_xmit_core net/l2tp/l2tp_core.c:1177 [inline]
RIP: 0010:[<ffffffff836bd7d5>]  [<ffffffff836bd7d5>] l2tp_xmit_skb+0x995/0xf60 net/l2tp/l2tp_core.c:1273
RSP: 0018:ffff8801aaabf8f0  EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff880197d1a3c0 RCX: ffffc90001142000
RDX: 0000000000000002 RSI: ffffffff836bd766 RDI: 0000000000000010
RBP: ffff8801aaabf970 R08: 00000000a100ffff R09: 0000000000000001
R10: ffff8801ba30c800 R11: 0000000000000001 R12: ffff8801c9318280
R13: 0000000000000012 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f87a313b700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001702076 CR3: 00000001cbbcc000 CR4: 00000000001606f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 0000000800000000 ffff880197d1a488 ffff8801c4db04b8 ffff8801c931837c
 ffff8801a870b408 ffff880197d1a490 ffff8801c4db0088 ffff880197d1a438
 0000000800000002 ffff8801c4db0038 ffff8801a870b400 ffff8801d57bc400
Call Trace:
 [<ffffffff836c9080>] pppol2tp_sendmsg+0x4e0/0x790 net/l2tp/l2tp_ppp.c:339
 [<ffffffff83017fcc>] sock_sendmsg_nosec net/socket.c:635 [inline]
 [<ffffffff83017fcc>] sock_sendmsg+0xcc/0x110 net/socket.c:645
 [<ffffffff830197ea>] ___sys_sendmsg+0x47a/0x840 net/socket.c:1969
 [<ffffffff8301bd41>] __sys_sendmmsg+0x161/0x3d0 net/socket.c:2059
 [<ffffffff8301bfe5>] SYSC_sendmmsg net/socket.c:2090 [inline]
 [<ffffffff8301bfe5>] SyS_sendmmsg+0x35/0x60 net/socket.c:2085
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839fb193>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 48 c1 ea 03 80 3c 02 00 0f 85 78 05 00 00 4d 8b b4 24 80 01 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d 7e 10 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 01 0f 8e e8 03 00 00 66 41 83 7e 10 
RIP  [<ffffffff836bd7d5>] l2tp_xmit_core net/l2tp/l2tp_core.c:1177 [inline]
RIP  [<ffffffff836bd7d5>] l2tp_xmit_skb+0x995/0xf60 net/l2tp/l2tp_core.c:1273
 RSP <ffff8801aaabf8f0>
---[ end trace ba81e184048daf5f ]---