syzbot

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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+0x23f5/0x24c0 net/xfrm/xfrm_state.c:783
Read of size 4 at addr ffff8801d42a7710 by task syz-executor028/2077

CPU: 0 PID: 2077 Comm: syz-executor028 Not tainted 4.4.169+ #1
 0000000000000000 7836bb36766aabdb ffff8801d42a6ed0 ffffffff81aab9c1
 0000000000000000 ffffea000750a9c0 ffff8801d42a7710 0000000000000004
 0000000000000003 ffff8801d42a6f08 ffffffff8148fc0d 0000000000000000
Call Trace:
 [<ffffffff81aab9c1>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81aab9c1>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<ffffffff8148fc0d>] print_address_description+0x6f/0x21b mm/kasan/report.c:252
 [<ffffffff8148fe45>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8148fe45>] kasan_report mm/kasan/report.c:408 [inline]
 [<ffffffff8148fe45>] kasan_report.cold+0x8c/0x2be mm/kasan/report.c:393
 [<ffffffff814849d4>] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:428
 [<ffffffff825633c5>] __xfrm6_daddr_saddr_hash net/xfrm/xfrm_hash.h:28 [inline]
 [<ffffffff825633c5>] __xfrm_dst_hash net/xfrm/xfrm_hash.h:95 [inline]
 [<ffffffff825633c5>] xfrm_dst_hash net/xfrm/xfrm_state.c:46 [inline]
 [<ffffffff825633c5>] xfrm_state_find+0x23f5/0x24c0 net/xfrm/xfrm_state.c:783
 [<ffffffff82549d77>] xfrm_tmpl_resolve_one+0x1c7/0x790 net/xfrm/xfrm_policy.c:1455
 [<ffffffff8254a550>] xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:1499 [inline]
 [<ffffffff8254a550>] xfrm_resolve_and_create_bundle+0x210/0x1df0 net/xfrm/xfrm_policy.c:1847
 [<ffffffff8254d4b3>] xfrm_lookup+0x203/0xad0 net/xfrm/xfrm_policy.c:2204
 [<ffffffff8254ec48>] xfrm_lookup_route+0x38/0x140 net/xfrm/xfrm_policy.c:2326
 [<ffffffff823a2703>] ip_route_output_flow+0x93/0xa0 net/ipv4/route.c:2437
 [<ffffffff8247cda7>] udp_sendmsg+0x1537/0x1c60 net/ipv4/udp.c:1040
 [<ffffffff82610002>] udpv6_sendmsg+0x12f2/0x24f0 net/ipv6/udp.c:1173
 [<ffffffff824a6112>] inet_sendmsg+0x202/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff821d50de>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff821d50de>] sock_sendmsg+0xbe/0x110 net/socket.c:648
 [<ffffffff821d6bb9>] ___sys_sendmsg+0x369/0x890 net/socket.c:1975
 [<ffffffff821da030>] __sys_sendmmsg+0x130/0x2e0 net/socket.c:2060
 [<ffffffff821da215>] SYSC_sendmmsg net/socket.c:2090 [inline]
 [<ffffffff821da215>] SyS_sendmmsg+0x35/0x60 net/socket.c:2085
 [<ffffffff827153a1>] entry_SYSCALL_64_fastpath+0x1e/0x9a

The buggy address belongs to the page:
page:ffffea000750a9c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d42a7600: 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00
 ffff8801d42a7680: f2 f2 f2 00 00 00 f2 f2 f2 f2 f2 00 00 00 00 00
>ffff8801d42a7700: 00 00 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 00 00
                         ^
 ffff8801d42a7780: f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00
 ffff8801d42a7800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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