==================================================================
BUG: KASAN: stack-out-of-bounds in __xfrm6_daddr_saddr_hash net/xfrm/xfrm_hash.h:28 [inline]
BUG: KASAN: stack-out-of-bounds in __xfrm_dst_hash net/xfrm/xfrm_hash.h:95 [inline]
BUG: KASAN: stack-out-of-bounds in xfrm_dst_hash net/xfrm/xfrm_state.c:46 [inline]
BUG: KASAN: stack-out-of-bounds in xfrm_state_find+0x233e/0x2410 net/xfrm/xfrm_state.c:783
Read of size 4 at addr ffff8801d7497660 by task syz-executor858/2205

CPU: 0 PID: 2205 Comm: syz-executor858 Not tainted 4.4.153+ #91
 0000000000000000 1746189d393eb3d8 ffff8801d7496ce0 ffffffff81a4510d
 ffffea00075d25c0 ffff8801d7497660 0000000000000000 ffff8801d7497660
 0000000000000002 ffff8801d7496d18 ffffffff8146a880 ffff8801d7497660
Call Trace:
 [<ffffffff81a4510d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81a4510d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff8146a880>] print_address_description+0x6c/0x217 mm/kasan/report.c:252
 [<ffffffff8146aba0>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8146aba0>] kasan_report.cold.6+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff8145fc84>] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:428
 [<ffffffff824ce61e>] __xfrm6_daddr_saddr_hash net/xfrm/xfrm_hash.h:28 [inline]
 [<ffffffff824ce61e>] __xfrm_dst_hash net/xfrm/xfrm_hash.h:95 [inline]
 [<ffffffff824ce61e>] xfrm_dst_hash net/xfrm/xfrm_state.c:46 [inline]
 [<ffffffff824ce61e>] xfrm_state_find+0x233e/0x2410 net/xfrm/xfrm_state.c:783
 [<ffffffff824b5a02>] xfrm_tmpl_resolve_one+0x1d2/0x7a0 net/xfrm/xfrm_policy.c:1455
 [<ffffffff824b61e3>] xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:1499 [inline]
 [<ffffffff824b61e3>] xfrm_resolve_and_create_bundle+0x213/0x1d70 net/xfrm/xfrm_policy.c:1847
 [<ffffffff824b9118>] xfrm_lookup+0x238/0xb70 net/xfrm/xfrm_policy.c:2201
 [<ffffffff824ba8f9>] xfrm_lookup_route+0x39/0x130 net/xfrm/xfrm_policy.c:2323
 [<ffffffff8230eb50>] ip_route_output_flow+0x90/0xa0 net/ipv4/route.c:2437
 [<ffffffff823e8710>] udp_sendmsg+0x1480/0x1c70 net/ipv4/udp.c:1040
 [<ffffffff8257942d>] udpv6_sendmsg+0x12cd/0x24c0 net/ipv6/udp.c:1173
 [<ffffffff82411bf3>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff8214696b>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff8214696b>] sock_sendmsg+0xbb/0x110 net/socket.c:648
 [<ffffffff82148491>] ___sys_sendmsg+0x441/0x880 net/socket.c:1975
 [<ffffffff8214ba1e>] __sys_sendmmsg+0x12e/0x2e0 net/socket.c:2060
 [<ffffffff8214bc05>] SYSC_sendmmsg net/socket.c:2090 [inline]
 [<ffffffff8214bc05>] SyS_sendmmsg+0x35/0x60 net/socket.c:2085
 [<ffffffff8267c6a1>] entry_SYSCALL_64_fastpath+0x1e/0x9a

The buggy address belongs to the page:
page:ffffea00075d25c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d7497500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801d7497580: 00 f1 f1 f1 f1 00 f2 f2 f2 f2 f2 f2 f2 00 00 00
>ffff8801d7497600: f2 f2 f2 f2 f2 00 00 00 00 00 00 00 f2 f2 f2 f2
                                                       ^
 ffff8801d7497680: f2 00 00 00 00 00 00 00 00 00 f2 f2 f2 00 00 00
 ffff8801d7497700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================