linux-kernel - Re: [PATCH] mm: memcontrol: fix possible css ref leak on oom

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20160529091133.GG26059@esperanza>
Date:	Sun, 29 May 2016 12:11:33 +0300
From:	Vladimir Davydov <vdavydov@...tuozzo.com>
To:	Johannes Weiner <hannes@...xchg.org>
CC:	Andrew Morton <akpm@...ux-foundation.org>,
	Michal Hocko <mhocko@...nel.org>, <linux-mm@...ck.org>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] mm: memcontrol: fix possible css ref leak on oom

On Fri, May 27, 2016 at 01:36:29PM -0400, Johannes Weiner wrote:
> On Mon, May 23, 2016 at 07:02:10PM +0300, Vladimir Davydov wrote:
> > mem_cgroup_oom may be invoked multiple times while a process is handling
> > a page fault, in which case current->memcg_in_oom will be overwritten
> > leaking the previously taken css reference.
> 
> There is a task_in_memcg_oom() check before calling mem_cgroup_oom().
> 
> How can this happen?

Oops, I overlooked that check. Scratch this patch then.

Sorry for the noise.