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

Stephen Smalley
2008-03-12T15:48:17Z

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.

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

> > Certainly will confuse matters if a user has audit filters on SELinux
> > users in their /etc/audit/audit.rules and then boots a kernel with Smack
> > enabled.
>
> Somehow I doubt that will be their biggest concern.

--
Stephen Smalley
National Security Agency