Node 0 DMA free:15908kB min:164kB low:204kB high:244kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15992kB managed:15908kB mlocked:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
==================================================================
lowmem_reserve[]:
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+0x1f76/0x2260 net/ipv6/ip6_output.c:264
Read of size 8 at addr ffff8801b6260918 by task syz-executor2/6279
 0

CPU: 1 PID: 6279 Comm: syz-executor2 Not tainted 4.16.0-rc5+ #354
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 2864
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x24d lib/dump_stack.c:53
 6373
 6373
 print_address_description+0x73/0x250 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report+0x23c/0x360 mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
Node 0 
 ip6_dst_idev include/net/ip6_fib.h:192 [inline]
 ip6_xmit+0x1f76/0x2260 net/ipv6/ip6_output.c:264
DMA32 free:2934568kB min:30292kB low:37864kB high:45436kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:3129292kB managed:2935316kB mlocked:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:748kB local_pcp:628kB free_cma:0kB
lowmem_reserve[]:
 0
 0
 inet6_csk_xmit+0x2fc/0x580 net/ipv6/inet6_connection_sock.c:139
 3509
 3509
 l2tp_xmit_core net/l2tp/l2tp_core.c:1053 [inline]
 l2tp_xmit_skb+0x105f/0x1410 net/l2tp/l2tp_core.c:1148
Node 0 
Normal free:2630948kB min:37120kB low:46400kB high:55680kB active_anon:368624kB inactive_anon:248kB active_file:14032kB inactive_file:34208kB unevictable:0kB writepending:580kB present:4718592kB managed:3593744kB mlocked:0kB kernel_stack:4832kB pagetables:3184kB bounce:0kB free_pcp:424kB local_pcp:168kB free_cma:0kB
 pppol2tp_sendmsg+0x470/0x670 net/l2tp/l2tp_ppp.c:341
lowmem_reserve[]:
 0
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:640
 ___sys_sendmsg+0x767/0x8b0 net/socket.c:2046
 0
 0
 0
Node 0 
 __sys_sendmsg+0xe5/0x210 net/socket.c:2080
DMA: 
1*4kB 
(U) 
 SYSC_sendmsg net/socket.c:2091 [inline]
 SyS_sendmsg+0x2d/0x50 net/socket.c:2087
0*8kB 
 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
0*16kB 
1*32kB 
(U) 
2*64kB 
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x453e69
(U) 
RSP: 002b:00007fcd8a3abc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fcd8a3ac6d4 RCX: 0000000000453e69
RDX: 000000000000c045 RSI: 0000000020002540 RDI: 0000000000000014
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
1*128kB 
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000004bd R14: 00000000006f7258 R15: 0000000000000000

(U) 
Allocated by task 0:
(stack is not available)

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8801b6260900
 which belongs to the cache ip_dst_cache of size 168
1*256kB 
The buggy address is located 24 bytes inside of
 168-byte region [ffff8801b6260900, ffff8801b62609a8)
The buggy address belongs to the page:
page:ffffea0006d89800 count:1 mapcount:0 mapping:ffff8801b6260000 index:0x0
(U) 
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801b6260000 0000000000000000 0000000100000010
raw: ffff8801d6bf5348 ffffea00072ef520 ffff8801d5b8e800 0000000000000000
0*512kB 
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801b6260800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801b6260880: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
1*1024kB 
>ffff8801b6260900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                            ^
 ffff8801b6260980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801b6260a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
(U) 
==================================================================