linux-kernel - Re: [PATCH 1/8] x86, microcode, intel: forbid some incorrect metadata

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20141006051536.GA4372@pd.tnic>
Date:	Mon, 6 Oct 2014 07:15:36 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	Henrique de Moraes Holschuh <hmh@....eng.br>
Cc:	linux-kernel@...r.kernel.org, H Peter Anvin <hpa@...or.com>
Subject: Re: [PATCH 1/8] x86, microcode, intel: forbid some incorrect metadata

On Sun, Oct 05, 2014 at 06:49:08PM -0300, Henrique de Moraes Holschuh wrote:
> How about this:
> 
> 	/*
> 	 * 0 is not a valid microcode revision as it is used to detect the
> 	 * absence of any sucessful microcode update since reset /
> 	 * power-on, see MSR 0x8b (IA32_BIOS_SIGN_ID):
> 	 *
> 	 * "It is required that this register field be pre-loaded with zero
> 	 * prior to executing the CPUID, function 1. If the field remains
> 	 * equal to zero, then there is no microcode update loaded. Another
> 	 * non-zero value will be the signature."
> 	 */
> 

Yep.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/