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BUG: KASAN: stack-out-of-bounds in memcmp+0x126/0x160 lib/string.c:742
Read of size 1 at addr ffff8801bb8878e0 by task syz-executor6/6145

CPU: 0 PID: 6145 Comm: syz-executor6 Not tainted 4.4.141-g1b37d68 #71
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 69b5db518e50943b ffff8801bb887410 ffffffff81e0e18d
 ffffea0006ee21c0 ffff8801bb8878e0 0000000000000000 ffff8801bb8878e0
 0000000000000000 ffff8801bb887448 ffffffff81515a86 ffff8801bb8878e0
Call Trace:
 [<ffffffff81e0e18d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81e0e18d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81515a86>] print_address_description+0x6c/0x216 mm/kasan/report.c:252
 [<ffffffff81515da5>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff81515da5>] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff814f9834>] __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:426
 [<ffffffff81e2a616>] memcmp+0x126/0x160 lib/string.c:742
 [<ffffffff833cecad>] addr_match include/net/xfrm.h:837 [inline]
 [<ffffffff833cecad>] __xfrm6_selector_match net/xfrm/xfrm_policy.c:81 [inline]
 [<ffffffff833cecad>] xfrm_selector_match+0x12d/0xe50 net/xfrm/xfrm_policy.c:95
 [<ffffffff833cfb21>] xfrm_sk_policy_lookup+0x151/0x350 net/xfrm/xfrm_policy.c:1241
 [<ffffffff833d28b5>] xfrm_lookup+0x1b5/0xb70 net/xfrm/xfrm_policy.c:2189
 [<ffffffff833d4189>] xfrm_lookup_route+0x39/0x1b0 net/xfrm/xfrm_policy.c:2323
 [<ffffffff83428fd7>] ip6_dst_lookup_flow+0x1b7/0x2f0 net/ipv6/ip6_output.c:1072
 [<ffffffff834cda58>] tcp_v6_connect+0xd58/0x1b70 net/ipv6/tcp_ipv6.c:249
 [<ffffffff832f9ec9>] __inet_stream_connect+0x2a9/0xc30 net/ipv4/af_inet.c:615
 [<ffffffff83249b90>] tcp_sendmsg_fastopen net/ipv4/tcp.c:1092 [inline]
 [<ffffffff83249b90>] tcp_sendmsg+0x1600/0x2b00 net/ipv4/tcp.c:1112
 [<ffffffff83301113>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff82f1e2fc>] sock_sendmsg_nosec net/socket.c:625 [inline]
 [<ffffffff82f1e2fc>] sock_sendmsg+0xcc/0x110 net/socket.c:635
 [<ffffffff82f1efdc>] SYSC_sendto+0x21c/0x370 net/socket.c:1665
 [<ffffffff82f21660>] SyS_sendto+0x40/0x50 net/socket.c:1633
 [<ffffffff838c2c25>] entry_SYSCALL_64_fastpath+0x22/0x9e

The buggy address belongs to the page:
page:ffffea0006ee21c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801bb887780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801bb887800: 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 f2 f2
>ffff8801bb887880: f2 f2 00 00 00 00 00 00 00 00 00 00 f2 f2 00 00
                                                       ^
 ffff8801bb887900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801bb887980: 00 00 00 f1 f1 f1 f1 00 00 00 00 00 f2 f2 f2 00
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