Re: [PATCH v2] cgroup: allow management of subtrees by new cgroup namespaces

[Aleksa Sarai]

> +	 * 3. cgroup core doesn't allow tasks to be migrated by users that have
> +	 *    write access to two subtrees unless they also have write access to
> +	 *    the common ancestor of the two subtrees. Thus you cannot use a
> +	 *    complicit process in less restrictive cgroup to overcome your own
> +	 *    cgroup restriction.

It appears this restriction isn't actually being applied on cgroupv1. 
I'll send an updated patch which makes sure the cgroup.proc common 
ancestor restriction is enforced for all hierarchies.

--
Aleksa Sarai
Software Engineer (Containers)
SUSE Linux GmbH
https://www.cyphar.com/