audit: type=1400 audit(1540198609.433:45): avc:  denied  { create } for  pid=7949 comm="syz-executor5" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=0
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BUG: KASAN: stack-out-of-bounds in memcmp+0x126/0x160 lib/string.c:742
Read of size 1 at addr ffff8801d1827920 by task syz-executor4/7974

CPU: 1 PID: 7974 Comm: syz-executor4 Not tainted 4.4.162+ #113
 0000000000000000 8a84d902a8b1c72f ffff8801d1827458 ffffffff81a994bd
 ffffea00074609c0 ffff8801d1827920 0000000000000000 ffff8801d1827920
 ffff8801d1827908 ffff8801d1827490 ffffffff8148a669 ffff8801d1827920
Call Trace:
 [<ffffffff81a994bd>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81a994bd>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff8148a669>] print_address_description+0x6c/0x217 mm/kasan/report.c:252
 [<ffffffff8148a989>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8148a989>] kasan_report.cold.6+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff8147f5a4>] __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:426
 [<ffffffff81ab5576>] memcmp+0x126/0x160 lib/string.c:742
 [<ffffffff8253d520>] addr_match include/net/xfrm.h:837 [inline]
 [<ffffffff8253d520>] __xfrm6_selector_match net/xfrm/xfrm_policy.c:81 [inline]
 [<ffffffff8253d520>] xfrm_selector_match+0x6a0/0xe50 net/xfrm/xfrm_policy.c:95
 [<ffffffff8253de21>] xfrm_sk_policy_lookup+0x151/0x350 net/xfrm/xfrm_policy.c:1241
 [<ffffffff8253e1dd>] xfrm_lookup+0x1bd/0xb70 net/xfrm/xfrm_policy.c:2192
 [<ffffffff8253fa39>] xfrm_lookup_route+0x39/0x140 net/xfrm/xfrm_policy.c:2326
 [<ffffffff8258f9c7>] ip6_dst_lookup_flow+0x1b7/0x2f0 net/ipv6/ip6_output.c:1072
 [<ffffffff826344ce>] tcp_v6_connect+0xcfe/0x1b00 net/ipv6/tcp_ipv6.c:249
 [<ffffffff82495089>] __inet_stream_connect+0x2a9/0xc30 net/ipv4/af_inet.c:615
 [<ffffffff823e9a47>] tcp_sendmsg_fastopen net/ipv4/tcp.c:1092 [inline]
 [<ffffffff823e9a47>] tcp_sendmsg+0x1a07/0x2b30 net/ipv4/tcp.c:1112
 [<ffffffff82496173>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff821c344b>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff821c344b>] sock_sendmsg+0xbb/0x110 net/socket.c:648
 [<ffffffff821c7670>] SYSC_sendto net/socket.c:1678 [inline]
 [<ffffffff821c7670>] SyS_sendto+0x220/0x370 net/socket.c:1646
 [<ffffffff82705fe1>] entry_SYSCALL_64_fastpath+0x1e/0x9a

The buggy address belongs to the page:
page:ffffea00074609c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d1827800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1
 ffff8801d1827880: f1 f1 00 00 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00
>ffff8801d1827900: 00 00 00 00 f2 f2 00 00 00 00 00 00 00 00 00 00
                               ^
 ffff8801d1827980: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
 ffff8801d1827a00: 00 00 00 00 00 f2 f2 f2 00 00 00 00 00 00 00 00
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