Re: [PATCH 8/8] Add FS_USERNS_FLAG to cgroup fs

From: Tejun Heo
Date: Tue Feb 16 2016 - 13:06:00 EST


On Fri, Jan 29, 2016 at 02:54:11AM -0600, serge.hallyn@xxxxxxxxxx wrote:
> From: Serge Hallyn <serge.hallyn@xxxxxxxxxx>
>
> allowing root in a non-init user namespace to mount it. This should
> now be safe, because
>
> 1. non-init-root cannot mount a previously unbound subsystem
> 2. the task doing the mount must be privileged with respect to the
> user namespace owning the cgroup namespace
> 3. the mounted subsystem will have its current cgroup as the root dentry.
> the permissions will be unchanged, so tasks will receive no new
> privilege over the cgroups which they did not have on the original
> mounts.
>
> Signed-off-by: Serge Hallyn <serge.hallyn@xxxxxxxxxxxxx>

Applied 1-8 to cgroup/for-4.6-ns w/ trivial stylistic updates.

Thanks.

--
tejun