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

[Vladimir Davydov]

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.