Fedora buildsys and SELinux

[Jeremy Katz]

On Mon, 2008-05-12 at 10:53 -0400, Stephen Smalley wrote:
> > On second thought is that even possible?  As I recall
> > selinux-policy-targeted rpm is installed about 128/129 packages when I
> > do my livecd create.  That means that we didn't even have an 'inside
> > chroot' policy to check against for the vast majority of this operation.
> > I'd assume that building the appropriete mock buildroot would have the
> > same problem.  Wonder how people would feel about really hacking up the
> > buildroot creator to force install selinux stuff first and then run the
> > full install transaction set....
> 
> For a normal install, anaconda has to set down an initial file contexts
> file and load a policy to get things started IIRC - otherwise rpm
> wouldn't be able to label the files it sets down prior to installing
> selinux-policy*.

It uses the policy from outside the chroot until things are put into the
chroot.  This "works" for the anaconda case as we don't really fully[1]
support installing a different environment than what your install images
are built with

Jeremy

[1] We've actually done a lot of work to make this more supported, but
SELinux is actually now the big blocker that I know of due to this
reasoning.  At least for things which count as similar, for certain
values of that.

> > > Or disable context validation altogether in userspace in that instance.
> > 
> > Anyone have suggestions on how to go about this?
> 
> Absence of any /selinux/context at all should automatically do that.
> 
> > > Or create some kind of "identity" node in the selinuxfs filesystem that
> > > is transaction-based like the existing selinuxfs nodes and always
> > > returns whatever was written to it, then bind mount that on top
> > > of /selinux/context.
> > 
> > I did get that out of using a plain file and using O_TRUNC in libselinux
> > eventually.
> 
> Yes, but I don't see how requiring the use of a hacked-up libselinux is
> any better or more workable.
>