Re: [PATCH v3 2/2] modules:capabilities: add a per-task modules autoload restriction

From: "Serge E. Hallyn" <serge@hallyn.com>
To: Djalal Harouni <tixxdz@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>,
	Kees Cook <keescook@chromium.org>,
	Andy Lutomirski <luto@kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	"Serge E. Hallyn" <serge@hallyn.com>,
	"kernel-hardening@lists.openwall.com"
	<kernel-hardening@lists.openwall.com>,
	LSM List <linux-security-module@vger.kernel.org>,
	Linux API <linux-api@vger.kernel.org>,
	Dongsu Park <dpark@posteo.net>,
	Casey Schaufler <casey@schaufler-ca.com>,
	James Morris <james.l.morris@oracle.com>,
	Paul Moore <paul@paul-moore.com>,
	Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jonathan Corbet <corbet@lwn.net>, Jessica Yu <jeyu@redhat.com>,
	Rusty Russell <rusty@rustcorp.com.au>,
	Arnaldo Carvalho de Melo <acme@redhat.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Ingo Molnar <mingo@ker>
Subject: Re: [PATCH v3 2/2] modules:capabilities: add a per-task modules autoload restriction
Date: Thu, 4 May 2017 09:58:33 -0500	[thread overview]
Message-ID: <20170504145832.GA28002@mail.hallyn.com> (raw)
In-Reply-To: <CAEiveUf4p1A1fggwibN+kJW7ruasQCmzr6=GSpTZXoyjJuz00Q@mail.gmail.com>

On Thu, May 04, 2017 at 03:07:49PM +0200, Djalal Harouni wrote:
> On Sat, Apr 22, 2017 at 2:17 PM, Djalal Harouni <tixxdz@gmail.com> wrote:
> > On Sat, Apr 22, 2017 at 1:28 AM, Andy Lutomirski <luto@amacapital.net> wrote:
> [...]
> >>
> >> My point is that all of these need some way to handle configuration
> >> and inheritance, and I don't think that a bunch of per-task prctls is
> >> the right way.  As just an example, saying that interactive users can
> >> autoload modules but other users can't, or that certain systemd
> >> services can, etc, might be nice.  Linus already complained that he
> >> (i.e. user "torvalds" or whatever) should be able to profile the
> >> kernel but that other uids should not be able to.
> >
> > Neat, maybe this could already be achieved with this interface and
> > systemd-logind,  "ModulesAutoloadUsers=andy" in logind.conf where
> > "andy" is the only logged-in user able to trigger and autoload kernel
> > modules. However maybe we should not restrict too much other bits or
> > functionality of the other users, please let me will follow up later
> > on it.
> >
> >> I personally like my implicit_rights idea, and it might be interesting
> >> to prototype it.
> >
> 
> Andy following on the idea of per user settings, I'm curious did you
> manage to make some advance on how to store the user settings ? the
> user database format is old and not extensible, there was cgmanager or

(v2 is under very very early consideration, would love to stay in the loop
as this is considered)

> other libcgroup but for resources, and no simple thing for such
> restrictions example: "RestrictLinuxModules=user" that will prevent
> such users from making/loading extra Linux features/modules that are
> not already available...
> 
> Thanks!
> 
> -- 
> tixxdz