Re: CVE-2023-52575: x86/srso: Fix SBPB enablement for spec_rstack_overflow=off

[Greg Kroah-Hartman]

On Mon, Apr 22, 2024 at 01:00:18PM +0200, Nikolay Borisov wrote:
> 
> 
> On 2.03.24 г. 23:00 ч., Greg Kroah-Hartman wrote:
> > Description
> > ===========
> > 
> > In the Linux kernel, the following vulnerability has been resolved:
> > 
> > x86/srso: Fix SBPB enablement for spec_rstack_overflow=off
> > 
> > If the user has requested no SRSO mitigation, other mitigations can use
> > the lighter-weight SBPB instead of IBPB.
> > 
> > The Linux kernel CVE team has assigned CVE-2023-52575 to this issue.
> 
> I'd like to dispute this as this isn't a CVE but a mere performance
> optimization in case spec_rstack_overflow is disabled. Without this patch in
> case spec_rstack_overflow is disabled the kernel will simply use the heavier
> ibpb but that won't have effect on correctness.

You are right, our fault.  I'll go reject this CVE now, thanks for the
review!

greg k-h