Re: [RFC][PATCH -v2] Smack: Integrate with Audit

Ahmed S. Darwish
2008-03-12T16:43:58Z

On Wed, Mar 12, 2008 at 11:48:17AM -0400, Stephen Smalley wrote:
>
> On Wed, 2008-03-12 at 08:40 -0700, Casey Schaufler wrote:
> > --- Stephen Smalley <sds@tycho.nsa.gov> wrote:
> >
> > >
> > > On Wed, 2008-03-12 at 04:44 +0200, Ahmed S. Darwish wrote:
> > > > Hi!,
> > > >
> > > > Setup the new Audit hooks for Smack. The AUDIT_SUBJ_USER and
> > > > AUDIT_OBJ_USER SELinux flags are recycled to avoid `auditd'
> > > > userspace modifications. Smack only needs auditing on
> > > > a subject/object bases, so those flags were enough.
> > >
> > > Only question I have is whether audit folks are ok with reuse of the
> > > flags in this manner, and whether the _USER flag is best suited for this
> > > purpose if you are going to reuse an existing flag (since Smack label
> > > seems more like a SELinux type than a SELinux user).
> >
> > To-mate-o toe-maht-o.
> >
> > There really doesn't seem to be any real reason to create a new
> > flag just because the granularity is different. The choice between
> > _USER and _TYPE (and _ROLE for that matter) is arbitrary from a
> > functional point of view. I say that since Smack has users, but
> > not types or roles, _USER makes the most sense.
>
> Perhaps I misunderstand, but Smack labels don't represent users (i.e.
> user identity) in any way, so it seemed like a mismatch to use the _USER
> flag there. Whereas types in SELinux bear some similarity to Smack
> labels - simple unstructured names whose meaning is only defined by the
> policy rules.
>

I think Casey meant the common use of Smack where a login program
(openssh, bin/login, ..) sets a label for each user that logs in, thus
letting each label effectively representing a user.

In a sense, smack labels share a bit of _USER and _TYPE.

> Regardless, it seems like the audit maintainers ought to weigh in on the
> matter.
>

Indeed.

Regards,

--

"Better to light a candle, than curse the darkness"

Ahmed S. Darwish
Homepage: http://darwish.07.googlepages.com
Blog: http://darwish-07.blogspot.com