Messages in this thread | | | Date | Fri, 26 Aug 2022 11:08:04 -1000 | From | Tejun Heo <> | Subject | Re: [PATCH 0/4] Honor cgroup namespace when resolving cgroup id |
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Hello,
On Fri, Aug 26, 2022 at 06:52:34PM +0200, Michal Koutný wrote: > Cgroup id is becoming a new way for userspace how to refer to cgroups it > wants to act upon. As opposed to cgroupfs (paths, opened FDs), the > current approach does not reflect limited view by (non-init) cgroup > namespaces.
Looking at the code, I'm not quite sure we're actually plugging all holes in terms of lookup. I think cgroup_get_from_path() would allow walking up past the ns boundary. We aren't using kernfs ns support and I don't see anything preventing ..'ing past the boundary.
> This patches don't aim to limit what a user can do (consider an uid=0 in > mere cgroup namespace) but to provide consistent view within a > namespace.
Considering userns and the fact that we try to isolate two separate sub hierarchies delegated to the same UID, I think we'd have to tighten down on the behaviors so that visiblity scope matches the permission scope.
Thanks.
-- tejun
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