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BUG: KASAN: stack-out-of-bounds in memcmp+0x126/0x160 lib/string.c:742
Read of size 1 at addr ffff8800b5b27be0 by task syz-executor3/10838

CPU: 1 PID: 10838 Comm: syz-executor3 Not tainted 4.4.138-g226f96b #63
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 e3a3821e4c82294f ffff8800b5b27710 ffffffff81e0ed0d
 ffffea0002d6c9c0 ffff8800b5b27be0 0000000000000000 ffff8800b5b27be0
 0000000000000000 ffff8800b5b27748 ffffffff81515a16 ffff8800b5b27be0
Call Trace:
 [<ffffffff81e0ed0d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81e0ed0d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81515a16>] print_address_description+0x6c/0x216 mm/kasan/report.c:252
 [<ffffffff81515d35>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff81515d35>] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff814f97c4>] __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:426
 [<ffffffff81e2b196>] memcmp+0x126/0x160 lib/string.c:742
 [<ffffffff833ce91d>] addr_match include/net/xfrm.h:837 [inline]
 [<ffffffff833ce91d>] __xfrm6_selector_match net/xfrm/xfrm_policy.c:81 [inline]
 [<ffffffff833ce91d>] xfrm_selector_match+0x12d/0xe50 net/xfrm/xfrm_policy.c:95
 [<ffffffff833cf791>] xfrm_sk_policy_lookup+0x151/0x350 net/xfrm/xfrm_policy.c:1236
 [<ffffffff833d2525>] xfrm_lookup+0x1b5/0xb70 net/xfrm/xfrm_policy.c:2184
 [<ffffffff833d3df9>] xfrm_lookup_route+0x39/0x1b0 net/xfrm/xfrm_policy.c:2318
 [<ffffffff83428c47>] ip6_dst_lookup_flow+0x1b7/0x2f0 net/ipv6/ip6_output.c:1072
 [<ffffffff834cd6c8>] tcp_v6_connect+0xd58/0x1b70 net/ipv6/tcp_ipv6.c:249
 [<ffffffff832f9b89>] __inet_stream_connect+0x2a9/0xc30 net/ipv4/af_inet.c:615
 [<ffffffff832fa565>] inet_stream_connect+0x55/0xa0 net/ipv4/af_inet.c:676
 [<ffffffff82f1eba8>] SYSC_connect+0x1b8/0x300 net/socket.c:1557
 [<ffffffff82f214e4>] SyS_connect+0x24/0x30 net/socket.c:1538
 [<ffffffff838c2725>] entry_SYSCALL_64_fastpath+0x22/0x9e

The buggy address belongs to the page:
page:ffffea0002d6c9c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8800b5b27a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8800b5b27b00: 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 f2 f2
>ffff8800b5b27b80: f2 f2 00 00 00 00 00 00 00 00 00 00 f2 f2 00 00
                                                       ^
 ffff8800b5b27c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8800b5b27c80: 00 00 00 f1 f1 f1 f1 00 00 00 00 00 f2 f2 f2 00
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