syzbot

random: sshd: uninitialized urandom read (32 bytes read)
random: crng init done
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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:60 [inline]
BUG: KASAN: stack-out-of-bounds in xfrm_state_find+0x269d/0x2920 net/xfrm/xfrm_state.c:807
Read of size 4 at addr ffff8801ce41f650 by task syz-executor175/2055

CPU: 1 PID: 2055 Comm: syz-executor175 Not tainted 4.9.141+ #1
 ffff8801ce41ecc0 ffffffff81b42e79 ffffea00073907c0 ffff8801ce41f650
 0000000000000000 ffff8801ce41f650 ffff8801ce876af0 ffff8801ce41ecf8
 ffffffff815009b8 ffff8801ce41f650 0000000000000004 0000000000000000
Call Trace:
 [<ffffffff81b42e79>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b42e79>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff815009b8>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff81500dc2>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff81500dc2>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff814f3054>] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 [<ffffffff826572ed>] __xfrm6_daddr_saddr_hash net/xfrm/xfrm_hash.h:28 [inline]
 [<ffffffff826572ed>] __xfrm_dst_hash net/xfrm/xfrm_hash.h:95 [inline]
 [<ffffffff826572ed>] xfrm_dst_hash net/xfrm/xfrm_state.c:60 [inline]
 [<ffffffff826572ed>] xfrm_state_find+0x269d/0x2920 net/xfrm/xfrm_state.c:807
 [<ffffffff8263cc82>] xfrm_tmpl_resolve_one+0x1d2/0x7a0 net/xfrm/xfrm_policy.c:1500
 [<ffffffff8263d46f>] xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:1544 [inline]
 [<ffffffff8263d46f>] xfrm_resolve_and_create_bundle+0x21f/0x1e70 net/xfrm/xfrm_policy.c:1893
 [<ffffffff82640569>] xfrm_lookup+0x239/0xc00 net/xfrm/xfrm_policy.c:2254
 [<ffffffff82641dc9>] xfrm_lookup_route+0x39/0x140 net/xfrm/xfrm_policy.c:2379
 [<ffffffff8248c500>] ip_route_output_flow+0x90/0xa0 net/ipv4/route.c:2448
 [<ffffffff8256be69>] udp_sendmsg+0x13d9/0x1c60 net/ipv4/udp.c:1025
 [<ffffffff8270876d>] udpv6_sendmsg+0x127d/0x2430 net/ipv6/udp.c:1086
 [<ffffffff825952f3>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:770
 [<ffffffff822a063b>] sock_sendmsg_nosec net/socket.c:648 [inline]
 [<ffffffff822a063b>] sock_sendmsg+0xbb/0x110 net/socket.c:658
 [<ffffffff822a209a>] ___sys_sendmsg+0x47a/0x840 net/socket.c:1982
 [<ffffffff822a55a1>] __sys_sendmmsg+0x161/0x3d0 net/socket.c:2072
 [<ffffffff822a5845>] SYSC_sendmmsg net/socket.c:2103 [inline]
 [<ffffffff822a5845>] SyS_sendmmsg+0x35/0x60 net/socket.c:2098
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82817893>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

The buggy address belongs to the page:
page:ffffea00073907c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801ce41f500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1
 ffff8801ce41f580: f1 f1 f1 00 f2 f2 f2 f2 f2 f2 f2 00 00 00 00 f2
>ffff8801ce41f600: f2 f2 f2 00 00 00 00 00 00 00 f2 f2 f2 f2 f2 00
                                                 ^
 ffff8801ce41f680: 00 00 00 00 00 00 00 00 f2 f2 f2 00 00 00 00 00
 ffff8801ce41f700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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