Re: [Xense-devel][RFC][PATCH][0/4] Xen Security Modules: Intro

[Chris Wright <chrisw@sous-sol.org>]

* George S. Coker, II (gscoker@alpha.ncsc.mil) wrote:
> On Fri, 2006-09-01 at 10:58 -0700, Chris Wright wrote:
> > * Jun Koi (junkoi2004@gmail.com) wrote:
> > > - LSM has a problem of not supporting stacking module, and that is
> > > really paint in the arse. How about XSM? Do you try to fix that
> > > problem?
> > 
> > I don't see anything in XSM that changes that limitation to LSM.  In fact,
> > it appears to not even support the very weak stacking via chaining
> > mechanism (which is a good plan in this case).  And it's questionable
> > at best.  Arbitrary security policies simply do not compose.
> 
> We have made a conscious decision not to bring LSM's stacking
> capabilities to Xen.

Yes, I think that's a wise decision (that's what I meant by good plan).

> Composition of security policies is difficult at
> best, and a given security modules behavior cannot be easily predicted
> under arbitrary stacking.  Arbitrary stacking risks eroding the security
> goals of an individual module while meeting few or none of the security
> goals of the user.  Stacking should be implemented within a security
> module that has been designed to stack specific modules to achieve a
> specific goal.

Indeed.  Sorry if my wording above was misleading, I'm in complete
agreement.

thanks,
-chris


> 
> George
> > thanks,
> > -chris
> 
> 
> 
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