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

[Reiner Sailer <sailer@us.ibm.com>]

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.

> LSM should not be used just because it has a few hooks in the right place
> for your code.
>
> 
> - James
> -- 
> James Morris
> <jmorris@redhat.com>
> 
> 
> 
> 

Thanks
Reiner