Re: [PATCH 4/5] LSM: Define SELinux function to measure security state

From: Stephen Smalley
Date: Mon Jun 15 2020 - 16:32:13 EST


On Mon, Jun 15, 2020 at 12:45 PM Lakshmi Ramasubramanian
<nramas@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On 6/15/20 4:57 AM, Stephen Smalley wrote:
> > I think I mentioned this on a previous version of these patches, but I
> > would recommend including more than just the enabled and enforcing
> > states in your measurement. Other low-hanging fruit would be the
> > other selinux_state booleans (checkreqprot, initialized,
> > policycap[0..__POLICYDB_CAPABILITY_MAX]). Going a bit further one
> > could take a hash of the loaded policy by using security_read_policy()
> > and then computing a hash using whatever hash ima prefers over the
> > returned data,len pair. You likely also need to think about how to
> > allow future extensibility of the state in a backward-compatible
> > manner, so that future additions do not immediately break systems
> > relying on older measurements.
> >
>
> Sure - I will address this one in the next update.

Please add selinux list to the cc for future versions too.