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

[Greg Kroah-Hartman]

On Tue, May 28, 2024 at 10:51:52AM +0200, Michal Hocko wrote:
> On Thu 23-05-24 14:14:57, Nikolay Borisov wrote:
> [...]
> > I'd like to dispute this CVE since it doesn't constitute a security related
> > bug. Sure, it might crash a SEV guest during boot but it doesn't constitute
> > a security issue per-se.
> 
> Let me add analysis by Joerg here:
> : This is not a security issue. The patch works around clangs compiler behavior
> : where it inserts absolute references to kernel addresses. This breaks kernel
> : boot because at the time this code runs the kernel still runs direct-mapped and
> : needs to rely on RIP-relative addressing only.
> : 
> : Any breakage there would be detected at early boot of the kernel by a fatal
> : crash, which can not be exploited. Also, our kernels are not compiled with
> : clang, so from that perspective this is also not an issue for us either.
> 
> So this is a functional fix for clang builds.

Thanks for the review, now rejected.

greg k-h