Re: [RFC 4/8] lsm: smack: smack callbacks for kdbus security hooks

[Paul Moore <pmoore@redhat.com>]

On Wednesday, July 08, 2015 09:38:25 AM Casey Schaufler wrote:
> On 7/8/2015 6:42 AM, Stephen Smalley wrote:
> > On 07/08/2015 06:25 AM, Paul Osmialowski wrote:

...

> > If Smack only truly needs 3 hooks, then it begs the question of why
> > there are so many other hooks defined.  Are the other hooks just to
> > support finer-grained distinctions, or is Smack's coverage incomplete?
> 
> I haven't been following kdbus closely for a while, but the original
> intent for Smack and kdbus was that it Smack controls would be on the
> objects involved, and that to accomplish that only a small number of
> hooks would be necessary. After all, Smack uses fewer hooks than SELinux
> on other things. I do agree that without a user there is no point in
> having hooks. If SELinux requires the other hooks we might want to
> hold off on asking for the hooks until the SELinux implementation is
> exposed. I also think that AppArmor should be examined as a potential
> user of the hooks, just to make sure the hooks aren't excessively
> oriented toward subject/object based security modules.

In Paul O.'s defense, we did have some discussion about the reasons for these 
hooks, although that seems like ages ago and I would need to dig through the 
archives (my inbox?) to find the reasoning for each.

However, I don't remember being very comfortable with the hooks back them 
largely due to uncertainty about how we were treating kdbus with respect to 
subjects/objects.  I think it's worth restarting that discussion now before we 
nit pick the patches themselves.

-- 
paul moore
security @ redhat