Re: CVE-2024-35802: x86/sev: Fix position dependent variable references in startup code

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, May 23, 2024 at 03:01:56PM +0300, Nikolay Borisov wrote:
> 
> 
> On 23.05.24 г. 14:21 ч., Greg Kroah-Hartman wrote:
> > Isn't crashing SEV guests a problem with "availability"?  That term
> > comes from the CVE definition of what we need to mark as a CVE, which is
> > why this one was picked.
> 
> But availability has never been one of the tenets of CoCo, in fact in
> sev-snp/tdx the VMM is explicitly considered outside of the TCB so
> availability cannot be guaranteed.

This has nothing to do with CoCo (but really, ability of the host to
crash the guest seems like it should be as I would assume that CoCo
guests would want to be able to be run...)

Official CVE definition of vulnerability from cve.org:
	An instance of one or more weaknesses in a Product that can be
	exploited, causing a negative impact to confidentiality, integrity, or
	availability; a set of conditions or behaviors that allows the
	violation of an explicit or implicit security policy.

I think "able to crash SEV guests" is a direct weakness that has to do
with availability here which is why I marked it as such (as did other
reviewers.)  Now if CoCo wants to claim it as part of their security
implicit or explicit security policy, all the better :)

thanks,

greg k-h