IPv6: Can't replace route, no match found
IPVS: set_ctl: invalid protocol: 0 127.0.0.1:20002 wlc
IPv6: Can't replace route, no match found
IPVS: set_ctl: invalid protocol: 108 0.0.0.0:20002 fo
==================================================================
BUG: KASAN: stack-out-of-bounds in string+0x25b/0x2a0 lib/vsprintf.c:592
Read of size 1 at addr ffff880190f17c34 by task syz-executor3/23904

CPU: 0 PID: 23904 Comm: syz-executor3 Not tainted 4.9.106-g8b94b87 #46
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff880190f17648 ffffffff81eb4209 ffffea000643c5c0 ffff880190f17c34
 0000000000000000 ffff880190f17c34 0000000000000034 ffff880190f17680
 ffffffff81567e99 ffff880190f17c34 0000000000000001 0000000000000000
Call Trace:
 [<ffffffff81eb4209>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb4209>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81567e99>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff815682a3>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff815682a3>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff8153be94>] __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
 [<ffffffff81ed662b>] string+0x25b/0x2a0 lib/vsprintf.c:592
 [<ffffffff81edf756>] vsnprintf+0x406/0x1840 lib/vsprintf.c:2044
 [<ffffffff81ee0bbd>] vscnprintf+0x2d/0x60 lib/vsprintf.c:2147
 [<ffffffff8125f7a4>] vprintk_emit+0xf4/0x790 kernel/printk/printk.c:1847
 [<ffffffff8125fe68>] vprintk+0x28/0x30 kernel/printk/printk.c:1913
 [<ffffffff8125fe8d>] vprintk_default+0x1d/0x30 kernel/printk/printk.c:1914
 [<ffffffff8142cf25>] vprintk_func kernel/printk/internal.h:36 [inline]
 [<ffffffff8142cf25>] printk+0xaf/0xd7 kernel/printk/printk.c:1975
 [<ffffffff839d2c49>] do_ip_vs_set_ctl.cold.36+0x34/0x39 net/netfilter/ipvs/ip_vs_ctl.c:2435
 [<ffffffff831df12d>] nf_sockopt net/netfilter/nf_sockopt.c:105 [inline]
 [<ffffffff831df12d>] nf_setsockopt+0x6d/0xc0 net/netfilter/nf_sockopt.c:114
 [<ffffffff8334931a>] ip_setsockopt+0x9a/0xb0 net/ipv4/ip_sockglue.c:1249
 [<ffffffff833f7d7a>] udp_setsockopt+0x4a/0x90 net/ipv4/udp.c:2091
 [<ffffffff835b4cda>] ipv6_setsockopt+0x10a/0x130 net/ipv6/ipv6_sockglue.c:901
 [<ffffffff833691f8>] tcp_setsockopt+0x88/0xe0 net/ipv4/tcp.c:2758
 [<ffffffff8301d75a>] sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2706
 [<ffffffff8301a516>] SYSC_setsockopt net/socket.c:1772 [inline]
 [<ffffffff8301a516>] SyS_setsockopt+0x166/0x260 net/socket.c:1751
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9b13>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

The buggy address belongs to the page:
page:ffffea000643c5c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff880190f17b00: f2 f2 f2 f2 f2 f2 00 00 00 00 00 04 f2 f2 f2 f2
 ffff880190f17b80: f2 f2 00 00 00 00 00 00 00 00 f2 f2 f2 f2 00 00
>ffff880190f17c00: 00 00 00 00 00 00 04 f2 f2 f2 00 00 00 00 00 00
                                     ^
 ffff880190f17c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff880190f17d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================