random: crng init done
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BUG: KASAN: stack-out-of-bounds in memcmp+0x126/0x160 lib/string.c:768
Read of size 1 at addr ffff8801b618fab0 by task syz-executor644/2290

CPU: 0 PID: 2290 Comm: syz-executor644 Not tainted 4.9.125+ #37
 ffff8801b618f388 ffffffff81af0ae9 ffffea0006d863c0 ffff8801b618fab0
 0000000000000000 ffff8801b618fab0 ffff8801b618fa98 ffff8801b618f3c0
 ffffffff814e0e1d ffff8801b618fab0 0000000000000001 0000000000000000
Call Trace:
 [<ffffffff81af0ae9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81af0ae9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff814e0e1d>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff814e1227>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff814e1227>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff814d3604>] __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
 [<ffffffff81b0cc86>] memcmp+0x126/0x160 lib/string.c:768
 [<ffffffff825b9970>] addr_match include/net/xfrm.h:833 [inline]
 [<ffffffff825b9970>] __xfrm6_selector_match net/xfrm/xfrm_policy.c:87 [inline]
 [<ffffffff825b9970>] xfrm_selector_match+0x6a0/0xe40 net/xfrm/xfrm_policy.c:101
 [<ffffffff825ba253>] xfrm_sk_policy_lookup+0x143/0x3c0 net/xfrm/xfrm_policy.c:1268
 [<ffffffff825ba68d>] xfrm_lookup+0x1bd/0xb70 net/xfrm/xfrm_policy.c:2217
 [<ffffffff825bbed9>] xfrm_lookup_route+0x39/0x140 net/xfrm/xfrm_policy.c:2351
 [<ffffffff8260b33b>] ip6_dst_lookup_flow+0x17b/0x210 net/ipv6/ip6_output.c:1098
 [<ffffffff82687095>] rawv6_sendmsg+0x9b5/0x2810 net/ipv6/raw.c:900
 [<ffffffff82510da3>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:770
 [<ffffffff8222361b>] sock_sendmsg_nosec net/socket.c:648 [inline]
 [<ffffffff8222361b>] sock_sendmsg+0xbb/0x110 net/socket.c:658
 [<ffffffff82223893>] sock_write_iter+0x223/0x3b0 net/socket.c:856
 [<ffffffff814e87a7>] new_sync_write fs/read_write.c:496 [inline]
 [<ffffffff814e87a7>] __vfs_write+0x3d7/0x580 fs/read_write.c:509
 [<ffffffff814eaff7>] vfs_write+0x187/0x520 fs/read_write.c:557
 [<ffffffff814eee29>] SYSC_write fs/read_write.c:604 [inline]
 [<ffffffff814eee29>] SyS_write+0xd9/0x1c0 fs/read_write.c:596
 [<ffffffff8100554f>] do_syscall_64+0x19f/0x480 arch/x86/entry/common.c:282
 [<ffffffff8278c193>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

The buggy address belongs to the page:
page:ffffea0006d863c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801b618f980: 00 00 00 00 00 00 00 00 f2 f2 f2 f2 00 00 f2 f2
 ffff8801b618fa00: f2 f2 f2 f2 00 00 f2 f2 f2 f2 f2 f2 00 00 00 00
>ffff8801b618fa80: 00 00 00 00 00 00 f2 f2 00 00 00 00 00 00 00 00
                                     ^
 ffff8801b618fb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801b618fb80: 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00 00 00
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