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

From: Michal Hocko
Date: Mon May 30 2016 - 03:26:39 EST


On Fri 27-05-16 13:36:29, 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?

Ble, I have missed that... Thanks for pointing that out

--
Michal Hocko
SUSE Labs