netfilter-devel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: syzbot <syzbot+da4494182233c23a5fcf@syzkaller.appspotmail.com>
To: bridge@lists.linux-foundation.org, coreteam@netfilter.org,
	davem@davemloft.net, dvyukov@google.com, fw@strlen.de,
	kadlec@blackhole.kfki.hu, linux-kernel@vger.kernel.org,
	netdev@vger.kernel.org, netfilter-devel@vger.kernel.org,
	pablo@netfilter.org, stephen@networkplumber.org,
	syzkaller-bugs@googlegroups.com
Subject: Re: KMSAN: uninit-value in ebt_stp_mt_check (2)
Date: Thu, 07 Jun 2018 14:40:01 -0700	[thread overview]
Message-ID: <0000000000002e2239056e142001@google.com> (raw)
In-Reply-To: <0000000000009a3b5b056e109e42@google.com>

syzbot has found a reproducer for the following crash on:

HEAD commit:    c6a6aed994b6 kmsan: remove dead code to trigger syzbot build
git tree:       https://github.com/google/kmsan.git/master
console output: https://syzkaller.appspot.com/x/log.txt?x=122606bf800000
kernel config:  https://syzkaller.appspot.com/x/.config?x=848e40757852af3e
dashboard link: https://syzkaller.appspot.com/bug?extid=da4494182233c23a5fcf
compiler:       clang version 7.0.0 (trunk 334104)
syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=121f481f800000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=121fbbd7800000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+da4494182233c23a5fcf@syzkaller.appspotmail.com

random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
==================================================================
BUG: KMSAN: uninit-value in ebt_stp_mt_check+0x24b/0x450  
net/bridge/netfilter/ebt_stp.c:162
CPU: 1 PID: 4523 Comm: syz-executor710 Not tainted 4.17.0+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x185/0x1d0 lib/dump_stack.c:113
  kmsan_report+0x149/0x260 mm/kmsan/kmsan.c:1084
  __msan_warning_32+0x6e/0xc0 mm/kmsan/kmsan_instr.c:620
  ebt_stp_mt_check+0x24b/0x450 net/bridge/netfilter/ebt_stp.c:162
  xt_check_match+0x1438/0x1650 net/netfilter/x_tables.c:506
  ebt_check_match net/bridge/netfilter/ebtables.c:372 [inline]
  ebt_check_entry net/bridge/netfilter/ebtables.c:702 [inline]
  translate_table+0x4e88/0x6120 net/bridge/netfilter/ebtables.c:943
  do_replace_finish+0x1258/0x2ea0 net/bridge/netfilter/ebtables.c:999
  do_replace+0x719/0x780 net/bridge/netfilter/ebtables.c:1138
  do_ebt_set_ctl+0x2ab/0x3c0 net/bridge/netfilter/ebtables.c:1517
  nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
  nf_setsockopt+0x47c/0x4e0 net/netfilter/nf_sockopt.c:115
  ip_setsockopt+0x24b/0x2b0 net/ipv4/ip_sockglue.c:1251
  udp_setsockopt+0x108/0x1b0 net/ipv4/udp.c:2416
  sock_common_setsockopt+0x13b/0x170 net/core/sock.c:3039
  __sys_setsockopt+0x496/0x540 net/socket.c:1903
  __do_sys_setsockopt net/socket.c:1914 [inline]
  __se_sys_setsockopt net/socket.c:1911 [inline]
  __x64_sys_setsockopt+0x15c/0x1c0 net/socket.c:1911
  do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x43fd89
RSP: 002b:00007ffc9d7edb28 EFLAGS: 00000213 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fd89
RDX: 0000000000000080 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000300 R09: 00000000004002c8
R10: 0000000020000480 R11: 0000000000000213 R12: 00000000004016b0
R13: 0000000000401740 R14: 0000000000000000 R15: 0000000000000000

Local variable description: ----mtpar.i@translate_table
Variable was created at:
  translate_table+0xbb/0x6120 net/bridge/netfilter/ebtables.c:831
  do_replace_finish+0x1258/0x2ea0 net/bridge/netfilter/ebtables.c:999
==================================================================

      parent reply	other threads:[~2018-06-07 21:40 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-07 17:29 KMSAN: uninit-value in ebt_stp_mt_check (2) syzbot
2018-06-07 17:34 ` Dmitry Vyukov
2018-06-07 21:40 ` syzbot [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=0000000000002e2239056e142001@google.com \
    --to=syzbot+da4494182233c23a5fcf@syzkaller.appspotmail.com \
    --cc=bridge@lists.linux-foundation.org \
    --cc=coreteam@netfilter.org \
    --cc=davem@davemloft.net \
    --cc=dvyukov@google.com \
    --cc=fw@strlen.de \
    --cc=kadlec@blackhole.kfki.hu \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=netfilter-devel@vger.kernel.org \
    --cc=pablo@netfilter.org \
    --cc=stephen@networkplumber.org \
    --cc=syzkaller-bugs@googlegroups.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).