Re: [PATCH] memcg: account security cred as well to kmemcg

[Shakeel Butt]

On Fri, Dec 6, 2019 at 4:13 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Thu,  5 Dec 2019 14:37:21 -0800 Shakeel Butt <shakeelb@xxxxxxxxxx> wrote:
>
> > The cred_jar kmem_cache is already memcg accounted in the current
> > kernel but cred->security is not. Account cred->security to kmemcg.
> >
> > Recently we saw high root slab usage on our production and on further
> > inspection, we found a buggy application leaking processes. Though that
> > buggy application was contained within its memcg but we observe much
> > more system memory overhead, couple of GiBs, during that period. This
> > overhead can adversely impact the isolation on the system. One of source
> > of high overhead, we found was cred->secuity objects.
>
> A bit of an oversight and the fix is simple.  Is it worth a cc:stable?

Yes, I think it is simple and safe enough for stable.