audit: type=1400 audit(1516827486.988:10): avc:  denied  { sys_chroot } for  pid=3668 comm="syzkaller904186" capability=18  scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
==================================================================
BUG: KASAN: slab-out-of-bounds in ip6_dst_idev include/net/ip6_fib.h:192 [inline]
BUG: KASAN: slab-out-of-bounds in ip6_xmit+0x1ce9/0x2090 net/ipv6/ip6_output.c:264
Read of size 8 at addr ffff8801c36bf318 by task syzkaller904186/3668

CPU: 1 PID: 3668 Comm: syzkaller904186 Not tainted 4.15.0-rc9+ #207
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 ip6_dst_idev include/net/ip6_fib.h:192 [inline]
 ip6_xmit+0x1ce9/0x2090 net/ipv6/ip6_output.c:264
 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+0x320/0x8b0 net/socket.c:2020
 __sys_sendmmsg+0x1ee/0x620 net/socket.c:2110
 SYSC_sendmmsg net/socket.c:2141 [inline]
 SyS_sendmmsg+0x35/0x60 net/socket.c:2136
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x44e199
RSP: 002b:00000000007efdf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000004b0010 RCX: 000000000044e199
RDX: 0000000000000007 RSI: 00000000204f2e78 RDI: 0000000000000005
RBP: 0000000000000068 R08: 00000000004b0010 R09: 00000000004b0010
R10: 000000002000c801 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000a R14: 0000000000000000 R15: 0000000000000000

Allocated by task 0:
(stack is not available)

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8801c36bf300
 which belongs to the cache ip_dst_cache of size 168
The buggy address is located 24 bytes inside of
 168-byte region [ffff8801c36bf300, ffff8801c36bf3a8)
The buggy address belongs to the page:
page:ffffea00070dafc0 count:1 mapcount:0 mapping:ffff8801c36bf000 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801c36bf000 0000000000000000 0000000100000010
raw: ffffea0007110560 ffff8801d6f55c48 ffff8801d6f54980 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c36bf200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801c36bf280: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
>ffff8801c36bf300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                            ^
 ffff8801c36bf380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801c36bf400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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