Re: [PATCH] x86/microcode/intel: Ensure new microcode processor flags match with cpu's pf

Borislav Petkov
2018-06-19T09:36:01Z

On Tue, Jun 19, 2018 at 05:24:20PM +0800, Zhenzhong Duan wrote:
> On 2018/6/19 17:12, Borislav Petkov wrote:
> > On Tue, Jun 19, 2018 at 12:49:40PM +0800, Zhenzhong Duan wrote:
> > > Imagine kernel already found a microcode blob A with extended sig/pf
> > > matching current cpu, then another microcode B is checked which doesn't
> > > match current cpu...
> > Do you see the
> >
> > if (!microcode_matches(mc_header, uci->cpu_sig.sig)) {
> >
> > call a couple of lines earlier?
> Sure, but it didn't ensure a match in stepping and pf, is that expected?

Do you see the

if (!has_newer_microcode(data,
uci->cpu_sig.sig,
uci->cpu_sig.pf,
uci->cpu_sig.rev))

a couple lines later?