==================================================================
BUG: KASAN: slab-out-of-bounds in ip6_dst_idev include/net/ip6_fib.h:141 [inline]
BUG: KASAN: slab-out-of-bounds in ip6_xmit+0x177c/0x1a00 net/ipv6/ip6_output.c:237
Read of size 8 at addr ffff8801d93df518 by task syz-executor2/8170

CPU: 0 PID: 8170 Comm: syz-executor2 Not tainted 4.4.152-ge5c5f1f #25
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 dca705c93adc4b2a ffff8801d869f548 ffffffff81e15fed
 ffffea000764f7c0 ffff8801d93df518 0000000000000000 ffff8801d93df518
 0000000000001200 ffff8801d869f580 ffffffff8151b489 ffff8801d93df518
Call Trace:
 [<ffffffff81e15fed>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81e15fed>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff8151b489>] print_address_description+0x6c/0x216 mm/kasan/report.c:252
 [<ffffffff8151b7a8>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8151b7a8>] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff814fe734>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429
 [<ffffffff83435efc>] ip6_dst_idev include/net/ip6_fib.h:141 [inline]
 [<ffffffff83435efc>] ip6_xmit+0x177c/0x1a00 net/ipv6/ip6_output.c:237
 [<ffffffff834f60c5>] inet6_csk_xmit+0x245/0x490 net/ipv6/inet6_connection_sock.c:176
 [<ffffffff835a570c>] l2tp_xmit_core net/l2tp/l2tp_core.c:1084 [inline]
 [<ffffffff835a570c>] l2tp_xmit_skb+0xb9c/0xe80 net/l2tp/l2tp_core.c:1179
 [<ffffffff835b1c60>] pppol2tp_sendmsg+0x4e0/0x7d0 net/l2tp/l2tp_ppp.c:355
 [<ffffffff82f2727c>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff82f2727c>] sock_sendmsg+0xcc/0x110 net/socket.c:648
 [<ffffffff82f28a41>] ___sys_sendmsg+0x441/0x880 net/socket.c:1975
 [<ffffffff82f2b0d4>] __sys_sendmmsg+0x1d4/0x2e0 net/socket.c:2053
 [<ffffffff83014b22>] C_SYSC_sendmmsg net/compat.c:728 [inline]
 [<ffffffff83014b22>] compat_SyS_sendmmsg+0x32/0x40 net/compat.c:725
 [<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
 [<ffffffff838cdec3>] sysenter_flags_fixed+0xd/0x1a

Allocated by task 0:
(stack is not available)

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8801d93df500
 which belongs to the cache ip_dst_cache of size 208
The buggy address is located 24 bytes inside of
 208-byte region [ffff8801d93df500, ffff8801d93df5d0)
The buggy address belongs to the page:
BUG: unable to handle kernel paging request at ffffe8ffffd0ee60
IP: [<ffffffff81587df0>] mntput_no_expire+0xc0/0x6c0 fs/namespace.c:1164
PGD 1d83fe067 PUD 1d83fd067 PMD ffffffff81490267 BAD
Oops: 000b [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 8183 Comm: blkid Not tainted 4.4.152-ge5c5f1f #25
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800bb280000 task.stack: ffff8800a47e0000
RIP: 0010:[<ffffffff81587df0>]  [<ffffffff81587df0>] mntput_no_expire+0xc0/0x6c0 fs/namespace.c:1164
RSP: 0018:ffff8800a47e7c98  EFLAGS: 00010246
RAX: 000060fe24a0ee60 RBX: ffff8801d991da00 RCX: 1ffffffff0942cd1
RDX: 1ffff1003b323b4a RSI: ffffffff81587dcd RDI: ffff8801d991da50
RBP: ffff8800a47e7cd8 R08: ffff8800bb280900 R09: 0000000000000000
R10: 0000000000000001 R11: ffff8800bb280000 R12: ffff8801d991da00
R13: ffff8800bb280758 R14: ffff8800bb2807f0 R15: ffff8800ba116e08
FS:  00007f7a6dd46740(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc7ff81490870 CR3: 00000000a7aa3000 CR4: 00000000001606f0
Stack:
 ffffffff81587d30 ffffffff8156d17d ffffffff8156d03a ffff8801d991da20
 ffff8801d991da00 ffff8800bb280758 ffff8800bb2807f0 ffff8800ba116e08
 ffff8800a47e7cf8 ffffffff81588451 ffff8800ba116e70 0000000000000000
Call Trace:
 [<ffffffff81588451>] mntput+0x61/0x90 fs/namespace.c:1219
 [<ffffffff815407d0>] path_put+0x50/0x70 fs/namei.c:507
 [<ffffffff815c53d6>] free_fs_struct+0x16/0x60 fs/fs_struct.c:89
 [<ffffffff815c6209>] exit_fs+0xe9/0x120 fs/fs_struct.c:108
 [<ffffffff8113828f>] do_exit+0x9bf/0x26b0 kernel/exit.c:751
 [<ffffffff8113e1f1>] do_group_exit+0x111/0x330 kernel/exit.c:885
 [<ffffffff8113e42d>] SYSC_exit_group kernel/exit.c:896 [inline]
 [<ffffffff8113e42d>] SyS_exit_group+0x1d/0x20 kernel/exit.c:894
 [<ffffffff838cc565>] entry_SYSCALL_64_fastpath+0x22/0x9e
Code: 00 00 00 e8 73 c7 dc ff 48 8d 7b 50 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 80 05 00 00 48 8b 43 50 <65> ff 08 e8 68 26 cf ff 85 c0 75 3b e8 3f c7 dc ff e8 aa 29 cf 
RIP  [<ffffffff81587df0>] mntput_no_expire+0xc0/0x6c0 fs/namespace.c:1164
 RSP <ffff8800a47e7c98>
CR2: ffffe8ffffd0ee60
---[ end trace 4750df666229d7bd ]---