linux-kernel - Re: [PATCH 1/4] x86/cpufeature: Add User-Mode Instruction Prevention definitions

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

Message-ID: <1478913845.2541.0.camel@ranerica-desktop>
Date:   Fri, 11 Nov 2016 17:24:05 -0800
From:   Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>
To:     Borislav Petkov <bp@...e.de>
Cc:     Andy Lutomirski <luto@...capital.net>,
        Ingo Molnar <mingo@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        X86 ML <x86@...nel.org>,
        "linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Brian Gerst <brgerst@...il.com>,
        Chen Yucong <slaoub@...il.com>,
        Chris Metcalf <cmetcalf@...lanox.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Fenghua Yu <fenghua.yu@...el.com>,
        Huang Rui <ray.huang@....com>, Jiri Slaby <jslaby@...e.cz>,
        Jonathan Corbet <corbet@....net>,
        "Michael S . Tsirkin" <mst@...hat.com>,
        Paul Gortmaker <paul.gortmaker@...driver.com>,
        Peter Zijlstra <peterz@...radead.org>,
        "Ravi V . Shankar" <ravi.v.shankar@...el.com>,
        Shuah Khan <shuah@...nel.org>, Vlastimil Babka <vbabka@...e.cz>
Subject: Re: [PATCH 1/4] x86/cpufeature: Add User-Mode Instruction
 Prevention definitions

On Fri, 2016-11-11 at 11:22 +0100, Borislav Petkov wrote:
> On Thu, Nov 10, 2016 at 08:08:07PM -0800, Ricardo Neri wrote:
> > UMIP is enabled by setting a bit in CR4. If that bit is not supposed
> > to be set, that could cause a #GP fault.
> 
> Yeah, you do check CPUID first, AFAICT, so you should be ok...

Right. I missed this detail. Yes, there should not be a problem.
> 
> -- 
> Regards/Gruss,
>     Boris.
> 
> SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)