Re: [PATCH try #2] security: Convert LSM into a static interface

Serge E. Hallyn
2007-06-27T18:51:38Z

Quoting Serge E. Hallyn (serue@us.ibm.com):
> Quoting James Morris (jmorris@namei.org):
> > On Wed, 27 Jun 2007, Serge E. Hallyn wrote:
> >
> > > Quoting Kyle Moffett (mrmacman_g4@mac.com):
> > > > This whole discussion boils down to 2 points:
> > >
> > > Yes it can, but not the two you list.
> > >
> > > > 1) As currently implemented, no LSM may be safely rmmod-ed
> > >
> > > That's not the rationale for the patch, it's just some talking point you
> > > picked up. The rationale for the patch is to prevent abuse.
> >
> > This is not correct. Reducing API abuse is simply a bonus.
> >
> > The rationale for the patch is to remove unneeded infrastructure which
> > complicates security by introducing the idea that the security module can
> > be removed at all.
> >
> > It was in response to your very own posting about the new capabilities
> > code which would need to take this into account.
>
> It's (IMO) by far not the optimal "solution" :) If it is felt a
> solution is really needed, re-introduction of a
> security_ops->module_exit hook and introduction of CAP_SYS_CAPDISABLE
> would be better.
>
> But I'm well aware there are far too many (separate and not so separate)
> agendas driving this, and have no expectations of being able to stop it.
>
> James, FWIW, I'm sorry I haven't had a chance to actually test the
> patch. I'll try to get around to that today or at least this week.

Patch tests fine for me for expected capability behavior with lsm=n,
lsm=y, lsm=y+capability=y, lsm=y+selinux=y, and lsm=y+caps=y+selinux=y.

So while I'm opposed to the patch, it appears to be safe.

thanks,
-serge