Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754929Ab1DOXWW (ORCPT ); Fri, 15 Apr 2011 19:22:22 -0400 Received: from out2.smtp.messagingengine.com ([66.111.4.26]:46929 "EHLO out2.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753221Ab1DOXWU (ORCPT ); Fri, 15 Apr 2011 19:22:20 -0400 X-Sasl-enc: pWtLwCuIAArjL45olahHH3hZJuH73EErI9s5PVpLo4bf 1302909740 Date: Fri, 15 Apr 2011 20:22:12 -0300 From: Henrique de Moraes Holschuh To: Borislav Petkov Cc: Ben Hutchings , "Ostrovsky, Boris" , "linux-kernel@vger.kernel.org" , "stable@kernel.org" , "akpm@linux-foundation.org" , "torvalds@linux-foundation.org" , "stable-review@kernel.org" , "alan@lxorguk.ukuu.org.uk" , Greg KH , Andreas Herrmann Subject: Re: [Stable-review] [56/74] x86, microcode, AMD: Extend ucode size verification Message-ID: <20110415232212.GA12829@khazad-dum.debian.net> References: <20110413155148.974006996@clark.kroah.org> <1302752223.5282.674.camel@localhost> <20110414074125.GA8575@aftab> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110414074125.GA8575@aftab> X-GPG-Fingerprint: 1024D/1CDB0FE3 5422 5C61 F6B7 06FB 7E04 3738 EE25 DE3F 1CDB 0FE3 User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1265 Lines: 30 On Thu, 14 Apr 2011, Borislav Petkov wrote: > > Good thing nothing important depends on this validation, oh wait... > > Oh wait, please don't tell me that you really think that the CPU relies > completely on software to do its ucode validation and accepts the "good" > ucode binary patch blindly... http://www.securiteam.com/securityreviews/5FP0M1PDFO.html If it is not a hoax, circa 2004 K8s would accept any crap that passed a simple checksum test. I don't trust the claims of strong crypto usage by Intel either, especially since AFAIK Intel itself never claimed to use anything strong, just that its microcode was "encrypted". I sure hope real crypto is used on the more recent cores from both vendors, though. Too bad we cannot lock down further microcode updates until the next hard reset... -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/