From: Tejun Heo <tj@kernel.org>
To: John Stultz <john.stultz@linaro.org>
Cc: lkml <linux-kernel@vger.kernel.org>,
Li Zefan <lizefan@huawei.com>, Jonathan Corbet <corbet@lwn.net>,
cgroups@vger.kernel.org,
Android Kernel Team <kernel-team@android.com>,
Rom Lemarchand <romlem@android.com>,
Colin Cross <ccross@android.com>,
Dmitry Shmidt <dimitrysh@google.com>,
Todd Kjos <tkjos@google.com>,
Christian Poetzsch <christian.potzsch@imgtec.com>,
Amit Pundir <amit.pundir@linaro.org>,
Serge Hallyn <serge.hallyn@canonical.com>
Subject: Re: [RFC][PATCH 0/2] Another pass at Android style loosening of cgroup attach permissions
Date: Tue, 4 Oct 2016 15:38:38 -0400 [thread overview]
Message-ID: <20161004193838.GH4205@htj.duckdns.org> (raw)
In-Reply-To: <CALAqxLUPMxpngbZCSFW9wS+LbZJbfSUxTDEXX2x-FUmuN4H+QQ@mail.gmail.com>
Hello, John.
On Tue, Oct 04, 2016 at 11:01:12AM -0700, John Stultz wrote:
> So to make sure I understand your suggestion, you're suggesting the
> cgroupfs files like:
> cpuctrl/tasks,
> cpuctrl/bg_non_interactive/tasks,
> cpuset/foreground/tasks,
> cpuset/background/tasks,
> etc
> use ACL permissions to specify the specific uids that can write to
> them? I guess this would be conceptually similar to just setting the
> owner to the system task, no? Though I'm not sure that would be
Yeah, finer grained but essentially just giving write perms.
> sufficient since it would still fail the
> cgroup_procs_write_permission() checks. Or are you suggesting we add
> extra logic to make the file owner uid as sufficient to change other
> tasks?
Hah, now I'm not sure how this is supposed to work inside a userns as
it's checking against GLOBAL_ROOT_UID. cc'ing Serge. Serge, can you
please have a look?
But back on subject, yeah, I think a capability based approach is
better here too. No idea how difficult it is to add a new CAP but I
think it's worth trying. Can you please spin up a patch?
Thanks!
--
tejun
next prev parent reply other threads:[~2016-10-04 19:38 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-04 4:41 John Stultz
2016-10-04 4:41 ` [PATCH 1/2] cgroup: Add generic cgroup subsystem permission checks John Stultz
2016-10-05 19:09 ` Dmitry Torokhov
2016-10-05 19:16 ` John Stultz
2016-10-05 19:23 ` Dmitry Torokhov
2016-10-04 4:41 ` [PATCH 2/2] cgroup: Add a allow_attach policy for Android John Stultz
2016-10-05 19:10 ` Dmitry Torokhov
2016-10-05 19:18 ` John Stultz
2016-10-06 22:43 ` Dmitry Torokhov
2016-10-06 22:52 ` Dmitry Torokhov
2016-10-04 16:16 ` [RFC][PATCH 0/2] Another pass at Android style loosening of cgroup attach permissions Tejun Heo
2016-10-04 18:01 ` John Stultz
2016-10-04 19:38 ` Tejun Heo [this message]
2016-10-04 19:46 ` John Stultz
2016-10-04 19:49 ` Tejun Heo
2016-10-04 20:18 ` Serge E. Hallyn
2016-10-04 20:33 ` Tejun Heo
2016-10-04 21:26 ` Serge E. Hallyn
2016-10-04 21:29 ` Tejun Heo
2016-10-04 18:03 ` John Stultz
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