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From: Michal Hocko <mhocko@suse.cz>
To: David Rientjes <rientjes@google.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>, linux-mm@kvack.org
Subject: Re: [PATCH 1/5] mm: Introduce OOM kill timeout.
Date: Tue, 25 Nov 2014 11:38:20 +0100	[thread overview]
Message-ID: <20141125103820.GA4607@dhcp22.suse.cz> (raw)
In-Reply-To: <alpine.DEB.2.10.1411241417250.7986@chino.kir.corp.google.com>

On Mon 24-11-14 14:29:00, David Rientjes wrote:
> On Mon, 24 Nov 2014, Michal Hocko wrote:
> 
> > > The problem described above is one of phenomena which is triggered by
> > > a vulnerability which exists since (if I didn't miss something)
> > > Linux 2.0 (18 years ago). However, it is too difficult to backport
> > > patches which fix the vulnerability.
> > 
> > What is the vulnerability?
> > 
> 
> There have historically been issues when oom killed processes fail to 
> exit, so this is probably trying to address one of those issues.

Let me clarify. The patch is sold as a security fix. In that context
vulnerability means a behavior which might be abused by a user. I was
merely interested whether there are some known scenarios which would
turn a potential OOM killer deadlock into an exploitable bug. The
changelog was rather unclear about it and rather strong in claims that
any user might trigger OOM deadlock.
-- 
Michal Hocko
SUSE Labs

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  reply	other threads:[~2014-11-25 10:38 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-23  4:49 [RFC PATCH 0/5] mm: Patches for mitigating memory allocation stalls Tetsuo Handa
2014-11-23  4:50 ` [PATCH 1/5] mm: Introduce OOM kill timeout Tetsuo Handa
2014-11-24 16:50   ` Michal Hocko
2014-11-24 22:29     ` David Rientjes
2014-11-25 10:38       ` Michal Hocko [this message]
2014-11-25 12:54         ` Tetsuo Handa
2014-11-25 13:45           ` Michal Hocko
2014-11-26 11:58             ` Tetsuo Handa
2014-11-26 18:43               ` Michal Hocko
2014-11-27 14:49                 ` Tetsuo Handa
2014-11-28 16:17                   ` Michal Hocko
2014-11-23  4:50 ` [PATCH 2/5] mm: Kill shrinker's global semaphore Tetsuo Handa
2014-11-24 16:55   ` Michal Hocko
2014-11-23  4:51 ` [PATCH 3/5] mm: Remember ongoing memory allocation status Tetsuo Handa
2014-11-24 17:01   ` Michal Hocko
2014-11-23  4:52 ` [PATCH 4/5] mm: Drop __GFP_WAIT flag when allocating from shrinker functions Tetsuo Handa
2014-11-24 17:14   ` Michal Hocko
2014-11-23  4:53 ` [PATCH 5/5] mm: Insert some delay if ongoing memory allocation stalls Tetsuo Handa
2014-11-24 17:19   ` Michal Hocko
2014-11-24 17:25 ` [RFC PATCH 0/5] mm: Patches for mitigating " Michal Hocko

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