syzbot

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BUG: KASAN: stack-out-of-bounds in strlen lib/string.c:481 [inline]
BUG: KASAN: stack-out-of-bounds in strlcpy+0x101/0x120 lib/string.c:141
Read of size 1 at addr ffff8801ca397b4c by task syzkaller680216/3319

CPU: 1 PID: 3319 Comm: syzkaller680216 Not tainted 4.9.75-g06fe41f #16
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801ca397a28 ffffffff81d93049 ffffea000728e5c0 ffff8801ca397b4c
 0000000000000000 ffff8801ca397b4c ffff8801ca397c30 ffff8801ca397a60
 ffffffff8153ca53 ffff8801ca397b4c 0000000000000001 0000000000000000
Call Trace:
 [<ffffffff81d93049>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d93049>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8153ca53>] print_address_description+0x73/0x280 mm/kasan/report.c:252
 [<ffffffff8153cf75>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8153cf75>] kasan_report+0x275/0x360 mm/kasan/report.c:408
 [<ffffffff8153d074>] __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:426
 [<ffffffff81db1911>] strlen lib/string.c:481 [inline]
 [<ffffffff81db1911>] strlcpy+0x101/0x120 lib/string.c:141
 [<ffffffff8313b633>] xt_copy_counters_from_user+0x163/0x2e0 net/netfilter/x_tables.c:844
 [<ffffffff8351a9b6>] do_add_counters+0x96/0x590 net/ipv6/netfilter/ip6_tables.c:1213
 [<ffffffff83520b9f>] compat_do_ip6t_set_ctl+0xbf/0x150 net/ipv6/netfilter/ip6_tables.c:1588
 [<ffffffff8309fbe8>] compat_nf_sockopt net/netfilter/nf_sockopt.c:143 [inline]
 [<ffffffff8309fbe8>] compat_nf_setsockopt+0x88/0x130 net/netfilter/nf_sockopt.c:155
 [<ffffffff83478b2a>] compat_ipv6_setsockopt+0x13a/0x1e0 net/ipv6/ipv6_sockglue.c:947
 [<ffffffff83219205>] inet_csk_compat_setsockopt+0x95/0x120 net/ipv4/inet_connection_sock.c:914
 [<ffffffff8322f5dd>] compat_tcp_setsockopt+0x3d/0x70 net/ipv4/tcp.c:2748
 [<ffffffff82edc362>] compat_sock_common_setsockopt+0xb2/0x140 net/core/sock.c:2717
 [<ffffffff82fdbaa9>] C_SYSC_setsockopt net/compat.c:398 [inline]
 [<ffffffff82fdbaa9>] compat_SyS_setsockopt+0x149/0x290 net/compat.c:381
 [<ffffffff81006fc7>] do_syscall_32_irqs_on arch/x86/entry/common.c:322 [inline]
 [<ffffffff81006fc7>] do_fast_syscall_32+0x2f7/0x890 arch/x86/entry/common.c:384
 [<ffffffff838b2334>] entry_SYSENTER_compat+0x74/0x83 arch/x86/entry/entry_64_compat.S:127

The buggy address belongs to the page:
page:ffffea000728e5c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801ca397a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801ca397a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801ca397b00: 00 f1 f1 f1 f1 00 00 00 00 04 f2 f2 f2 00 00 00
                                              ^
 ffff8801ca397b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801ca397c00: 00 00 f1 f1 f1 f1 00 00 00 00 00 f2 f2 f2 00 00
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