netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: syzbot <syzbot+9e60d2428a42049a592a@syzkaller.appspotmail.com>
To: davem@davemloft.net, linux-kernel@vger.kernel.org,
	linux-s390@vger.kernel.org, netdev@vger.kernel.org,
	syzkaller-bugs@googlegroups.com, ubraun@linux.ibm.com
Subject: WARNING: refcount bug in smc_tcp_listen_work
Date: Wed, 06 Jun 2018 06:32:02 -0700	[thread overview]
Message-ID: <00000000000026a9d3056df931ea@google.com> (raw)

Hello,

syzbot found the following crash on:

HEAD commit:    75d4e704fa8d netdev-FAQ: clarify DaveM's position for stab..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1632a6f7800000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7b76ec81cd4aad4b
dashboard link: https://syzkaller.appspot.com/bug?extid=9e60d2428a42049a592a
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+9e60d2428a42049a592a@syzkaller.appspotmail.com

A link change request failed with some changes committed already. Interface  
bridge0 may have been left with an inconsistent configuration, please check.
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 23870 at lib/refcount.c:187  
refcount_sub_and_test+0x2d3/0x330 lib/refcount.c:187
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 23870 Comm: kworker/0:4 Not tainted 4.17.0-rc7+ #79
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: events smc_tcp_listen_work
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x1b9/0x294 lib/dump_stack.c:113
  panic+0x22f/0x4de kernel/panic.c:184
  __warn.cold.8+0x163/0x1b3 kernel/panic.c:536
  report_bug+0x252/0x2d0 lib/bug.c:186
  fixup_bug arch/x86/kernel/traps.c:178 [inline]
  do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296
  do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
  invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
RIP: 0010:refcount_sub_and_test+0x2d3/0x330 lib/refcount.c:187
RSP: 0018:ffff880194aaf4f8 EFLAGS: 00010286
RAX: 0000000000000026 RBX: 0000000000000000 RCX: ffffffff8160b8ad
RDX: 0000000000000000 RSI: ffffffff81610561 RDI: ffff880194aaf058
RBP: ffff880194aaf5e0 R08: ffff88014148e500 R09: 0000000000000006
R10: ffff88014148e500 R11: 0000000000000000 R12: 00000000ffffffff
R13: ffff880194aaf5b8 R14: 0000000000000001 R15: ffff880194aaf728
  refcount_dec_and_test+0x1a/0x20 lib/refcount.c:212
  sock_put include/net/sock.h:1668 [inline]
  smc_tcp_listen_work+0xb94/0xec0 net/smc/af_smc.c:1073
  process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145
  worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279
  kthread+0x345/0x410 kernel/kthread.c:240
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
Dumping ftrace buffer:
    (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with  
syzbot.

                 reply	other threads:[~2018-06-06 13:32 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

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=00000000000026a9d3056df931ea@google.com \
    --to=syzbot+9e60d2428a42049a592a@syzkaller.appspotmail.com \
    --cc=davem@davemloft.net \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=syzkaller-bugs@googlegroups.com \
    --cc=ubraun@linux.ibm.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).