Re: RETBleed: WARNING: Spectre v2 mitigation leaves CPU vulnerable to RETBleed attacks, data leaks possible!

[Peter Zijlstra]

On Thu, Jul 14, 2022 at 11:01:12AM +0200, Greg Kroah-Hartman wrote:
> On Thu, Jul 14, 2022 at 02:15:07PM +0530, Naresh Kamboju wrote:
> > Results from Linaro’s test farm.
> > 
> > We are booting the i386 kernel on an x86 machine.
> > With Spectre V2 patches merged into Linux mainline we have been noticing
> > RETBleed: WARNING: Spectre v2 mitigation leaves CPU vulnerable to
> > RETBleed attacks, data leaks possible!
> 
> That's funny.  I don't think that's a valid combination that should be
> cared about, but I'll leave it to Pawan to comment if it is something
> that is "real" to be concerned for.

Yeah, so far nobody cared to fix 32bit. If someone *realllllly* cares
and wants to put the effort in I suppose I'll review the patches, but
seriously, you shouldn't be running 32bit kernels on Skylake / Zen based
systems, that's just silly.