linux-kernel - Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

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: <1899038.KOOHvy2XUu@vostro.rjw.lan>
Date:	Tue, 09 Sep 2014 01:15:23 +0200
From:	"Rafael J. Wysocki" <rjw@...ysocki.net>
To:	Tejun Heo <tj@...nel.org>
Cc:	Cong Wang <xiyou.wangcong@...il.com>,
	LKML <linux-kernel@...r.kernel.org>,
	David Rientjes <rientjes@...gle.com>,
	Michal Hocko <mhocko@...e.cz>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

On Tuesday, September 09, 2014 07:50:12 AM Tejun Heo wrote:
> Hello,
> 
> On Tue, Sep 09, 2014 at 12:48:28AM +0200, Rafael J. Wysocki wrote:
> > Well, not exactly from anywhere.  Just from where try_to_freeze() is called
> > I suppose?
> 
> Yeap, anywhere try_to_freeze() may be called.
> 
> > Which means that if this is a user space task, it won't to a lot before dying,
> > will it?
> 
> Userland tasks aren't likely to a lot of damages before dying but then
> again there's no guarantee.  As it currently stands, try_to_freeze()
> can be anywhere.

Well, in that case the TIF_MEMDIE test alone is not sufficient in my opinion,
because we can't guarantee that the task will not do something it was frozen
to prevent it from doing.

I'm not sure about the cgroups freezing case, however.

Rafael

--
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/