linux-kernel - Re: use-after-free in __perf_install_in

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CACT4Y+ZTM7ine2Sz2H=TpGVuXgTg4An+LwiGPNLUcYcMQHcx1Q@mail.gmail.com>
Date:	Thu, 17 Dec 2015 15:35:32 +0100
From:	Dmitry Vyukov <dvyukov@...gle.com>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	syzkaller <syzkaller@...glegroups.com>,
	Kostya Serebryany <kcc@...gle.com>,
	Alexander Potapenko <glider@...gle.com>,
	Eric Dumazet <edumazet@...gle.com>,
	Sasha Levin <sasha.levin@...cle.com>
Subject: Re: use-after-free in __perf_install_in_context

On Thu, Dec 17, 2015 at 3:28 PM, Peter Zijlstra <peterz@...radead.org> wrote:
>> > >> I'm not sure I can explain your problem with this, but I figure its
>> > >> worth a try.
>> > >
>> > > Did it make a difference?
>> > >
>> > > Also, does the syzkaller thing do cpu-hotplug during its runs?
>> >
>> > See my email on Dec 15.
>>
>> I have 4 emails from you on that day (and one private), they pertain to
>> getting stuck in perf_{install,remove}_from_context(). None of those
>> emails seem to contain an answer to either of the two above questions.
>>
>>   CACT4Y+Za4L4q6FZLXjyGbnSYRwa7RJZYcG_s562q+CrNy9C75w@...l.gmail.com
>>   CACT4Y+YUkYgCuQFW6eBTtdfRqdF7EEtrB3VaYJk+LUXE_-iGRQ@...l.gmail.com
>>   CACT4Y+bvHWuyDZjoFhLAOiK1rfNQcfuSJCY0oS5xA=u8j04bXQ@...l.gmail.com
>>   CACT4Y+an67KnTsVVzYVvrYKW9yg7PbDuC8WyB38PiWRoSt0UCQ@...l.gmail.com
>>
>> and in private:
>>
>>   CACT4Y+Zb1vU192JbCnyS9qY3cpsvfAUJdpBVUsmosueCtQjSXQ@...l.gmail.com
>>
>> Did I miss an email?
>
> Yes, I seem to have missed this one:
>
>   CACT4Y+Y_YdEd-YGdWq-wQV6S+1M2nKA6atYO2DOFa8-wtQ8QWg@...l.gmail.com
>
> found it, thanks!

Yes, that one.
In short, I did not see use-after-frees but perf_event_open fuzzing
started hanging VMs very frequently, so testing is inconclusive.

And, no, nobody touches anything in /sys/devices.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/