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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20180619093552.GB30870@zn.tnic>
Date:   Tue, 19 Jun 2018 11:35:52 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Zhenzhong Duan <zhenzhong.duan@...cle.com>
Cc:     Linux-Kernel <linux-kernel@...r.kernel.org>, mingo@...hat.com,
        tglx@...utronix.de, Srinivas REDDY Eeda <srinivas.eeda@...cle.com>,
        hpa@...or.com
Subject: Re: [PATCH] x86/microcode/intel: Ensure new microcode processor
 flags match with cpu's pf

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?

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.