Re: [PATCH 1 of 4] ima: related TPM device driver interal kernel interface

[Greg KH <greg@kroah.com>]

On Fri, May 20, 2005 at 04:41:23PM -0400, Reiner Sailer wrote:
> James Morris <jmorris@redhat.com> wrote on 05/20/2005 04:32:58 PM:
> > On Fri, 20 May 2005, Reiner Sailer wrote:
> > 
> > > > Why are you using LSM for this?
> > > > 
> > > > LSM should be used for comprehensive access control frameworks which 
> > > > significantly enhance or even replace existing Unix DAC security.
> > > 
> > > I see LSM is framework for security. IMA is an architecture that
> > > enforces access control in a different way than SELinux. IMA guarantees 
> > > that executable content is measured and accounted for before
> > > it is loaded and can access (and possibly corrupt) system resources.
> > 
> > LSM is an access control framework.  Your (few) LSM hooks always return
> > zero, and don't enforce access control at all.  You even have a separate
> > measurement hook for modules.
> > 
> > I suggest implementing all of your code via distinct measurement hooks, so 
> > measurement becomes a distinct and well defined security entity within the 
> > kernel.
> 
> This is certainly possible. This means that there will be 5 more hooks
> (such as the one in kernel/module.c, see PATCH 4 of 4).
> 
> If the kernel maintainers are in favor of this approach, then there is not
> much that stands against this.

Yes, and it will force you to justify those hooks :)

Good luck,

greg k-h