Re: [PATCH] SELinux: Measure state and hash of policy using IMA

From: Paul Moore <paul@paul-moore.com>
To: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Cc: Ondrej Mosnacek <omosnace@redhat.com>,
	Stephen Smalley <stephen.smalley.work@gmail.com>,
	Mimi Zohar <zohar@linux.ibm.com>,
	Casey Schaufler <casey@schaufler-ca.com>,
	Tyler Hicks <tyhicks@linux.microsoft.com>,
	tusharsu@linux.microsoft.com, Sasha Levin <sashal@kernel.org>,
	James Morris <jmorris@namei.org>,
	linux-integrity@vger.kernel.org,
	SElinux list <selinux@vger.kernel.org>,
	LSM List <linux-security-module@vger.kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] SELinux: Measure state and hash of policy using IMA
Date: Mon, 24 Aug 2020 18:18:05 -0400	[thread overview]
Message-ID: <CAHC9VhQP7_rV+Oi6weLjVhrx2d8iu9UJ8zeE=ZcqnBMqngrJ4Q@mail.gmail.com> (raw)
In-Reply-To: <f041e8ee-3955-9551-b72d-d4d7fa6e636d@linux.microsoft.com>

On Mon, Aug 24, 2020 at 5:29 PM Lakshmi Ramasubramanian
<nramas@linux.microsoft.com> wrote:
> On 8/24/20 1:01 PM, Ondrej Mosnacek wrote:
> > On Mon, Aug 24, 2020 at 9:30 PM Stephen Smalley
> > <stephen.smalley.work@gmail.com> wrote:
> >> On Mon, Aug 24, 2020 at 2:13 PM Lakshmi Ramasubramanian
> >> <nramas@linux.microsoft.com> wrote:
> >>> On 8/24/20 7:00 AM, Stephen Smalley wrote:

...

> >>> Is Ondrej's re-try approach I need to use to workaround policy reload issue?
> >>
> >> No, I think perhaps we should move the mutex to selinux_state instead
> >> of selinux_fs_info.  selinux_fs_info has a pointer to selinux_state so
> >> it can then use it indirectly.  Note that your patches are going to
> >> conflict with other ongoing work in the selinux next branch that is
> >> refactoring policy load and converting the policy rwlock to RCU.
> >
> > Yeah, and I'm experimenting with a patch on top of Stephen's RCU work
> > that would allow you to do this in a straightforward way without even
> > messing with the fsi->mutex. My patch may or may not be eventually
> > committed, but either way I'd recommend holding off on this for a
> > while until the dust settles around the RCU conversion.
>
> I can make the SELinux\IMA changes in "selinux next branch" taking
> dependencies on Stephen's patches + relevant IMA patches.

I know it can be frustrating to hear what I'm about to say, but the
best option is probably just to wait a little to let things settle in
the SELinux -next branch.  There is a lot of stuff going on right now
with patches flooding in (at least "flooding" from a SELinux kernel
development perspective) and we/I've haven't gotten through all of
them yet.

> Could you please let me know the URL to the "selinux next branch"?

git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux.git next

-- 
paul moore
www.paul-moore.com