Re: [PATCH 5/9] Make use of permissions, returned by kobj_lookup

Stephen Smalley
2008-03-07T19:55:42Z

On Fri, 2008-03-07 at 12:30 -0600, Serge E. Hallyn wrote:
> Quoting Casey Schaufler (casey@schaufler-ca.com):
> >
> > --- "Serge E. Hallyn" <serue@us.ibm.com> wrote:
> >
> > > ...
> > >
> > > Until user namespaces are complete, selinux seems the only good solution
> > > to offer isolation.
> >
> > Smack does it better and cheaper. (Unless you define good==selinux)
> > (insert smiley)
>
> Ah, thanks - I hadn't looked into it, but yes IIUC smack should
> definately work. I'll have to give that a shot.

Not if you want to confine uid 0. smack doesn't control capabilities,
even the ones used to override it.

So you'd have to at least configure your per-process bset and file caps
rather carefully. And even then you have to watch out for things with
CAP_MAC* or CAP_SETPCAP.

> (A basic selinux policy module to isolate a container was pretty simple,
> but providing finer-grained intra-container access seems to take some
> changes to the base refpolicy. I've been waiting a few weeks to find
> time to work on that.)

--
Stephen Smalley
National Security Agency