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BUG: KASAN: stack-out-of-bounds in memcmp+0x126/0x160 lib/string.c:742
Read of size 1 at addr ffff8801ce84fbe0 by task syz-executor6/8500

CPU: 1 PID: 8500 Comm: syz-executor6 Not tainted 4.4.120-gd63fdf6 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 c915e21598775e2a ffff8801ce84f718 ffffffff81d0408d
 ffffea00073a13c0 ffff8801ce84fbe0 0000000000000000 ffff8801ce84fbe0
 ffff8801ce84fbc8 ffff8801ce84f750 ffffffff814fe143 ffff8801ce84fbe0
Call Trace:
 [<ffffffff81d0408d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0408d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff814fe143>] print_address_description+0x73/0x260 mm/kasan/report.c:252
 [<ffffffff814fe655>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff814fe655>] kasan_report+0x285/0x370 mm/kasan/report.c:408
 [<ffffffff814fe754>] __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:426
 [<ffffffff81d20466>] memcmp+0x126/0x160 lib/string.c:742
 [<ffffffff832a86f7>] addr_match include/net/xfrm.h:837 [inline]
 [<ffffffff832a86f7>] __xfrm6_selector_match net/xfrm/xfrm_policy.c:81 [inline]
 [<ffffffff832a86f7>] xfrm_selector_match+0x1c7/0xe50 net/xfrm/xfrm_policy.c:95
 [<ffffffff832a94d3>] xfrm_sk_policy_lookup+0x153/0x360 net/xfrm/xfrm_policy.c:1236
 [<ffffffff832ac26e>] xfrm_lookup+0x1be/0xc10 net/xfrm/xfrm_policy.c:2184
 [<ffffffff832adbc9>] xfrm_lookup_route+0x39/0x1a0 net/xfrm/xfrm_policy.c:2318
 [<ffffffff83302754>] ip6_dst_lookup_flow+0x1b4/0x2e0 net/ipv6/ip6_output.c:1070
 [<ffffffff833a860e>] tcp_v6_connect+0xade/0x1b90 net/ipv6/tcp_ipv6.c:249
 [<ffffffff831d0d46>] __inet_stream_connect+0x2a6/0xc70 net/ipv4/af_inet.c:615
 [<ffffffff831d1765>] inet_stream_connect+0x55/0xa0 net/ipv4/af_inet.c:676
 [<ffffffff82dec596>] SYSC_connect+0x1b6/0x310 net/socket.c:1557
 [<ffffffff82deee04>] SyS_connect+0x24/0x30 net/socket.c:1538
 [<ffffffff8377395f>] entry_SYSCALL_64_fastpath+0x1c/0x98

The buggy address belongs to the page:
page:ffffea00073a13c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801ce84fa80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801ce84fb00: 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 f2 f2
>ffff8801ce84fb80: f2 f2 00 00 00 00 00 00 00 00 00 00 f2 f2 00 00
                                                       ^
 ffff8801ce84fc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801ce84fc80: 00 00 00 f1 f1 f1 f1 00 00 00 00 00 f2 f2 f2 00
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