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BUG: KASAN: stack-out-of-bounds in memcmp+0x126/0x160 lib/string.c:742
Read of size 1 at addr ffff8801d6c17b60 by task syz-executor5/17745

CPU: 1 PID: 17745 Comm: syz-executor5 Not tainted 4.4.125-g38f41ec #21
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 db9473e3b0ac9d2d ffff8801d6c17698 ffffffff81d067bd
 ffffea00075b05c0 ffff8801d6c17b60 0000000000000000 ffff8801d6c17b60
 ffff8801d6c17b48 ffff8801d6c176d0 ffffffff814fea83 ffff8801d6c17b60
Call Trace:
 [<ffffffff81d067bd>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d067bd>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff814fea83>] print_address_description+0x73/0x260 mm/kasan/report.c:252
 [<ffffffff814fef95>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff814fef95>] kasan_report+0x285/0x370 mm/kasan/report.c:408
 [<ffffffff814ff094>] __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:426
 [<ffffffff81d22bd6>] memcmp+0x126/0x160 lib/string.c:742
 [<ffffffff832ae477>] addr_match include/net/xfrm.h:837 [inline]
 [<ffffffff832ae477>] __xfrm6_selector_match net/xfrm/xfrm_policy.c:81 [inline]
 [<ffffffff832ae477>] xfrm_selector_match+0x1c7/0xe50 net/xfrm/xfrm_policy.c:95
 [<ffffffff832af253>] xfrm_sk_policy_lookup+0x153/0x360 net/xfrm/xfrm_policy.c:1236
 [<ffffffff832b1fee>] xfrm_lookup+0x1be/0xc10 net/xfrm/xfrm_policy.c:2184
 [<ffffffff832b3949>] xfrm_lookup_route+0x39/0x1a0 net/xfrm/xfrm_policy.c:2318
 [<ffffffff833084d4>] ip6_dst_lookup_flow+0x1b4/0x2e0 net/ipv6/ip6_output.c:1070
 [<ffffffff833ae37e>] tcp_v6_connect+0xade/0x1b90 net/ipv6/tcp_ipv6.c:249
 [<ffffffff831d6e26>] __inet_stream_connect+0x2a6/0xc70 net/ipv4/af_inet.c:615
 [<ffffffff831d7845>] inet_stream_connect+0x55/0xa0 net/ipv4/af_inet.c:676
 [<ffffffff82df21b6>] SYSC_connect+0x1b6/0x310 net/socket.c:1557
 [<ffffffff82df4a24>] SyS_connect+0x24/0x30 net/socket.c:1538
 [<ffffffff81006d91>] do_syscall_32_irqs_on arch/x86/entry/common.c:392 [inline]
 [<ffffffff81006d91>] do_fast_syscall_32+0x321/0x8a0 arch/x86/entry/common.c:459
 [<ffffffff8377b2aa>] sysenter_flags_fixed+0xd/0x17

The buggy address belongs to the page:
page:ffffea00075b05c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d6c17a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801d6c17a80: 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 f2 f2
>ffff8801d6c17b00: f2 f2 00 00 00 00 00 00 00 00 00 00 f2 f2 00 00
                                                       ^
 ffff8801d6c17b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801d6c17c00: 00 00 00 00 f1 f1 f1 f1 00 00 00 00 00 f2 f2 f2
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