All of lore.kernel.org
 help / color / mirror / Atom feed
From: Wei Wei <dotweiba@gmail.com>
To: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	edumazet@google.com, davem@davemloft.net, willemb@google.com,
	syzkaller@googlegroups.com
Subject: Re: v4.14-rc3/arm64 DABT exception in atomic_inc() / __skb_clone()
Date: Fri, 20 Oct 2017 10:40:38 -0400	[thread overview]
Message-ID: <960D71EC-C1E9-4898-ACBE-543FC09483FF@gmail.com> (raw)
In-Reply-To: <20171020111408.edj24tztxdptte5r@lakrids.cambridge.arm.com>

Sadly, the syzkaller characterized it as a non-reproducible bug and there were empty
 repro files. But if manually executing in VM like this “./syz-execprog -executor=
./syz-executor -repeat=0 -procs=16 -cover=0 crash-log”, it crashed when executing exactly 
program 1056 using log0 provided.

I failed to generate the C reproducer with syz-repro as it said “no target compiler”
in the final step. I would appreciate if you could give some hints.

Thanks,
Wei
> On 20 Oct 2017, at 7:14 AM, Mark Rutland <mark.rutland@arm.com> wrote:
> 
> On Thu, Oct 19, 2017 at 10:16:08PM -0400, Wei Wei wrote:
>> Hi all,
> 
> Hi,
> 
>> I have fuzzed v4.14-rc3 using syzkaller and found a bug similar to that one [1].
>> But the call trace isn’t the same. The atomic_inc() might handle a corrupted 
>> skb_buff.
>> 
>> The logs and config have been uploaded to my github repo [2].
>> 
>> [1] https://lkml.org/lkml/2017/10/2/216
>> [2] https://github.com/dotweiba/skb_clone_atomic_inc_bug
> 
> These do look very similar to what I was hitting; all appear to be
> misaligned atomics in the same path.
> 
> I see that you have some empty repro files in [2]. If you have any
> reproducers, would you mind sharing them?
> 
> If any of those are smaller or more reliable than the one I was able to
> generate [3], it might make it more obvious what's going on, and/or make
> it simpler to come up with a plain C reproducer.
> 
> Thanks,
> Mark.
> 
> [3] https://www.kernel.org/pub/linux/kernel/people/mark/bugs/20171002-skb_clone-misaligned-atomic/syzkaller.repro

WARNING: multiple messages have this Message-ID (diff)
From: dotweiba@gmail.com (Wei Wei)
To: linux-arm-kernel@lists.infradead.org
Subject: v4.14-rc3/arm64 DABT exception in atomic_inc() / __skb_clone()
Date: Fri, 20 Oct 2017 10:40:38 -0400	[thread overview]
Message-ID: <960D71EC-C1E9-4898-ACBE-543FC09483FF@gmail.com> (raw)
In-Reply-To: <20171020111408.edj24tztxdptte5r@lakrids.cambridge.arm.com>

Sadly, the syzkaller characterized it as a non-reproducible bug and there were empty
 repro files. But if manually executing in VM like this ?./syz-execprog -executor=
./syz-executor -repeat=0 -procs=16 -cover=0 crash-log?, it crashed when executing exactly 
program 1056 using log0 provided.

I failed to generate the C reproducer with syz-repro as it said ?no target compiler?
in the final step. I would appreciate if you could give some hints.

Thanks,
Wei
> On 20 Oct 2017, at 7:14 AM, Mark Rutland <mark.rutland@arm.com> wrote:
> 
> On Thu, Oct 19, 2017 at 10:16:08PM -0400, Wei Wei wrote:
>> Hi all,
> 
> Hi,
> 
>> I have fuzzed v4.14-rc3 using syzkaller and found a bug similar to that one [1].
>> But the call trace isn?t the same. The atomic_inc() might handle a corrupted 
>> skb_buff.
>> 
>> The logs and config have been uploaded to my github repo [2].
>> 
>> [1] https://lkml.org/lkml/2017/10/2/216
>> [2] https://github.com/dotweiba/skb_clone_atomic_inc_bug
> 
> These do look very similar to what I was hitting; all appear to be
> misaligned atomics in the same path.
> 
> I see that you have some empty repro files in [2]. If you have any
> reproducers, would you mind sharing them?
> 
> If any of those are smaller or more reliable than the one I was able to
> generate [3], it might make it more obvious what's going on, and/or make
> it simpler to come up with a plain C reproducer.
> 
> Thanks,
> Mark.
> 
> [3] https://www.kernel.org/pub/linux/kernel/people/mark/bugs/20171002-skb_clone-misaligned-atomic/syzkaller.repro

  reply	other threads:[~2017-10-20 14:40 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-20  2:16 v4.14-rc3/arm64 DABT exception in atomic_inc() / __skb_clone() Wei Wei
2017-10-20  2:16 ` Wei Wei
2017-10-20  2:53 ` Eric Dumazet
2017-10-20  2:53   ` Eric Dumazet
2017-10-20  3:13   ` Wei Wei
2017-10-20  3:13     ` Wei Wei
2017-10-20  5:34     ` Eric Dumazet
2017-10-20  5:34       ` Eric Dumazet
2017-10-20  9:18       ` Will Deacon
2017-10-20  9:18         ` Will Deacon
2017-10-20 11:14 ` Mark Rutland
2017-10-20 11:14   ` Mark Rutland
2017-10-20 14:40   ` Wei Wei [this message]
2017-10-20 14:40     ` Wei Wei
2017-10-20 15:11     ` Mark Rutland
2017-10-20 15:11       ` Mark Rutland
2017-10-20 15:14     ` Dmitry Vyukov
2017-10-20 15:14       ` Dmitry Vyukov
2017-10-20 15:39       ` Willem de Bruijn
2017-10-20 15:39         ` Willem de Bruijn
2017-10-22  1:56         ` Wei Wei
2017-10-22  1:56           ` Wei Wei
2017-10-25 18:24           ` Willem de Bruijn
2017-10-25 18:24             ` Willem de Bruijn
2017-10-25 18:49             ` Willem de Bruijn
2017-10-25 18:49               ` Willem de Bruijn
2017-10-25 19:01               ` Eric Dumazet
2017-10-25 19:01                 ` Eric Dumazet
2017-10-26  5:38                 ` Jason Wang
2017-10-26  5:38                   ` Jason Wang
2017-10-26 15:24               ` David Laight
2017-10-26 15:24                 ` David Laight
2017-10-26 15:24                 ` David Laight

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=960D71EC-C1E9-4898-ACBE-543FC09483FF@gmail.com \
    --to=dotweiba@gmail.com \
    --cc=davem@davemloft.net \
    --cc=edumazet@google.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=netdev@vger.kernel.org \
    --cc=syzkaller@googlegroups.com \
    --cc=willemb@google.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.