Re: [AppArmor 39/45] AppArmor: Profile loading and manipulation,pathname matching

From: Karl MacMillan
Date: Fri Jun 15 2007 - 18:24:44 EST


On Fri, 2007-06-15 at 14:44 -0700, Greg KH wrote:
> On Fri, Jun 15, 2007 at 05:28:35PM -0400, Karl MacMillan wrote:
> > On Fri, 2007-06-15 at 14:14 -0700, Greg KH wrote:
> > > On Fri, Jun 15, 2007 at 01:43:31PM -0700, Casey Schaufler wrote:
> > > >
> > > > Yup, I see that once you accept the notion that it is OK for a
> > > > file to be misslabeled for a bit and that having a fixxerupperd
> > > > is sufficient it all falls out.
> > > >
> > > > My point is that there is a segment of the security community
> > > > that had not found this acceptable, even under the conditions
> > > > outlined. If it meets your needs, I say run with it.
> > >
> > > If that segment feels that way, then I imagine AA would not meet their
> > > requirements today due to file handles and other ways of passing around
> > > open files, right?
> > >
> > > So, would SELinux today (without this AA-like daemon) fit the
> > > requirements of this segment?
> > >
> >
> > Yes - RHEL 5 is going through CC evaluations for LSPP, CAPP, and RBAC
> > using the features of SELinux where appropriate.
>
> Great, but is there the requirement in the CC stuff such that this type
> of "delayed re-label" that an AA-like daemon would need to do cause that
> model to not be able to be certified like your SELinux implementation
> is?
>

There are two things:

1) relabeling (non-tranquility) is very problematic in general because
revocation is hard (and non-solved in Linux). So you would have to
address concerns about that.

2) Whether this would pass certification depends on a lot of factors
(like the specific requirements - CC is just a process not a single set
of requirements). I don't know enough to really guess.

More to the point, though, the requirements in those documents are
outdated at best. I don't think it is worth worrying over.

> As I'm guessing the default "label" for things like this already work
> properly for SELinux, I figure we should be safe, but I don't know those
> requirements at all.
>

Probably not - you would likely want it to be a label that can't be read
or written by anything, only relabeled by the daemon.

Karl


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