linux-kernel - Re: sched: fair: NULL ptr deref in check_preempt

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: <53027A12.9090106@oracle.com>
Date:	Mon, 17 Feb 2014 16:07:30 -0500
From:	Sasha Levin <sasha.levin@...cle.com>
To:	Michael wang <wangyun@...ux.vnet.ibm.com>,
	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>
CC:	Dave Jones <davej@...hat.com>, LKML <linux-kernel@...r.kernel.org>
Subject: Re: sched: fair: NULL ptr deref in check_preempt_wakeup

On 02/17/2014 03:11 AM, Michael wang wrote:
> Hi, Sasha
>
> On 02/16/2014 07:27 AM, Sasha Levin wrote:
>> Hi folks,
>>
>> While fuzzing with trinity inside a KVM tools guest running latest -next
>> kernel, I've
>> stumbled on the following:
>
> I've reproduced the same issue with tip/master, and below patch fixed the
> problem on my box along with some rcu stall info disappeared, would you
> like to have a try?
>
> BTW, I reproduced it by steps:
> 1. change current to RT
> 2. move to a different depth cpu-cgroup
> 3. change it back to FAIR
>
> Seems like it was caused by that RT has no task_move_group() implemented
> which could maintain depth, and that lead to a wrong depth after switched
> back to FAIR...

I *think* it works. There seems to be another sched issue that causes lockups,
so I can't say for certain that this one doesn't occur anymore.

I'm still working on collecting data for the other issue, I'll mail about it soon.


Thanks,
Sasha

--
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/