==================================================================
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:60 [inline]
BUG: KASAN: stack-out-of-bounds in xfrm_state_find+0x26ce/0x27c0 net/xfrm/xfrm_state.c:806
Read of size 4 at addr ffff8801c464f860 by task syz-executor6/9631

CPU: 1 PID: 9631 Comm: syz-executor6 Not tainted 4.9.92-g4fb542f #2
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801c464eed8 ffffffff81d9c509 ffffea00071193c0 ffff8801c464f860
 0000000000000000 ffff8801c464f860 00000000000000fc ffff8801c464ef10
 ffffffff8156556b ffff8801c464f860 0000000000000004 0000000000000000
Call Trace:
 [<ffffffff81d9c509>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d9c509>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8156556b>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff815657df>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff815657df>] kasan_report.cold.6+0xac/0x2f5 mm/kasan/report.c:412
 [<ffffffff815395d4>] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 [<ffffffff833f12ee>] __xfrm_dst_hash net/xfrm/xfrm_hash.h:95 [inline]
 [<ffffffff833f12ee>] xfrm_dst_hash net/xfrm/xfrm_state.c:60 [inline]
 [<ffffffff833f12ee>] xfrm_state_find+0x26ce/0x27c0 net/xfrm/xfrm_state.c:806
 [<ffffffff833d466c>] xfrm_tmpl_resolve_one+0x1dc/0x850 net/xfrm/xfrm_policy.c:1483
 [<ffffffff833d4ef9>] xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:1527 [inline]
 [<ffffffff833d4ef9>] xfrm_resolve_and_create_bundle+0x219/0x1ff0 net/xfrm/xfrm_policy.c:1875
 [<ffffffff833dbb6f>] xfrm_lookup+0x23f/0xb70 net/xfrm/xfrm_policy.c:2229
 [<ffffffff833dd3a9>] xfrm_lookup_route+0x39/0x1b0 net/xfrm/xfrm_policy.c:2351
 [<ffffffff831f3700>] ip_route_output_flow+0x90/0xa0 net/ipv4/route.c:2438
 [<ffffffff832d297f>] udp_sendmsg+0x140f/0x1bd0 net/ipv4/udp.c:1023
 [<ffffffff834a421d>] udpv6_sendmsg+0x127d/0x2430 net/ipv6/udp.c:1086
 [<ffffffff83305e83>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:770
 [<ffffffff82ef3fcc>] sock_sendmsg_nosec net/socket.c:635 [inline]
 [<ffffffff82ef3fcc>] sock_sendmsg+0xcc/0x110 net/socket.c:645
 [<ffffffff82ef4cbc>] SYSC_sendto+0x21c/0x370 net/socket.c:1670
 [<ffffffff82ef72d0>] SyS_sendto+0x40/0x50 net/socket.c:1638
 [<ffffffff81006da7>] do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
 [<ffffffff81006da7>] do_fast_syscall_32+0x2f7/0x870 arch/x86/entry/common.c:387
 [<ffffffff838d6fd0>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

The buggy address belongs to the page:
page:ffffea00071193c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c464f700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801c464f780: 00 f1 f1 f1 f1 00 f2 f2 f2 f2 f2 f2 f2 00 00 00
>ffff8801c464f800: 00 f2 f2 f2 f2 00 00 00 00 00 00 00 f2 f2 f2 f2
                                                       ^
 ffff8801c464f880: f2 00 00 00 00 00 00 00 00 00 f2 f2 f2 00 00 00
 ffff8801c464f900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================