linux-kernel - Re: [ckrm-tech] [PATCH 1/7] containers (V7): Generic container system abstracted from cpusets code

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]

Date:	Sun, 25 Mar 2007 10:35:07 +0530
From:	Srivatsa Vaddagiri <vatsa@...ibm.com>
To:	Paul Jackson <pj@....com>
Cc:	sekharan@...ibm.com, ckrm-tech@...ts.sourceforge.net,
	linux-kernel@...r.kernel.org, xemul@...ru, dev@...ru,
	rohitseth@...gle.com, ebiederm@...ssion.com, mbligh@...gle.com,
	winget@...gle.com, containers@...ts.osdl.org, serue@...ibm.com,
	menage@...gle.com, devel@...nvz.org
Subject: Re: [ckrm-tech] [PATCH 1/7] containers (V7): Generic container system abstracted from cpusets code

On Sat, Mar 24, 2007 at 09:45:50PM -0700, Paul Jackson wrote:
> Nice work - thanks.  Yes, both an extra cpuset count and a negative
> cpuset count are bad news, opening the door to the usual catastrophes.
> 
> Would you like the honor of submitting the patch to add a task_lock
> to cpuset_exit()?  If you do, be sure to fix, or at least remove,
> the cpuset_exit comment lines:

I will try to send out a patch later today to fix this bug in mainline
cpuset code. I happened to notice this race with my rcfs patch and observed 
same is true with cpuset/container code also.

>  * We don't need to task_lock() this reference to tsk->cpuset,
>  * because tsk is already marked PF_EXITING, so attach_task() won't
>  * mess with it, or task is a failed fork, never visible to attach_task.

Sure, I had seen that.

> So, in real life, this would be a difficult race to trigger.

Agreed, but good to keep code clean isn't it? :)

> Thanks for finding this.

Wellcome!

-- 
Regards,
vatsa
-
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/