Received: by 10.223.185.111 with SMTP id b44csp1239253wrg; Sat, 10 Mar 2018 01:20:05 -0800 (PST) X-Google-Smtp-Source: AG47ELtVTSQbf9lWrwYGsbtUUKyndwslx/J+DFgpFucu8P97Pb0WI2DOIZL94U8IA4SH8HzPXVlo X-Received: by 10.99.116.25 with SMTP id p25mr1239527pgc.109.1520673605695; Sat, 10 Mar 2018 01:20:05 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1520673605; cv=none; d=google.com; s=arc-20160816; b=FsTLNvuM9AXeVTDJhsacfTDMmpBEKDlp1Jrh3l/WoyFttsFA92MCyj2abv0xCScWKW ATqhWVMWn8dzulIMjsfUukiCxR3odPz9XA2LSXHe0yGu3NTb8uaP9IJwpwJoRSaYoYbT tz2qtKmpKPuXYpfClRbYY9qaYS/nxIP18ckPtposB4D9Ucnw/ZALFU2WZtgBF23Nj58L vXSZUsdSeMjs4Yw9YKfsXn4EVI3D1xgrlWiskRSNunt14tlMfFmCNzekqBDZBI3iUK2n xpYKYo8X6/A1AaLfricOOFgrCVjTgYTtklkaij77irs5LRHmuOeIsVOqfVetfH2lm2lg Mdig== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:arc-authentication-results; bh=10NMe3z9NU3LYvAYDvNS05TvVK2K75df++DZzYfOOnE=; b=EmsTWV2qeYQpnkyt3cJlATWJqUDqrhG44C3uqu0k4oYgr+NPPhpPuIAJP54iREP4cA q6voJV3QDeKkqaMtjC5SRXLPEzCTwL/YZ9lEulJ0c6XyHStn8p5ZyydOjIBLMmDG3lQR h8Mkm9TfKuRm5hcbx2qfzobqcIADpAd8izu3jKxn7DN14LPO0ZRLSSFzpE04AEvck89g iJ5Uz/ZDuk/OTs+KGkbXd5pqxpPanoI8J92v+hkXsvGoJ1Xqx+DT36HMpEARSC1wKFCB CCimGpHNwx3BCPlYyFm5E0quhniYrBbmlFAdVhfQQFm3r0FsULIAVumWod0pAMsktFKx J62Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id z7si285558pgp.438.2018.03.10.01.19.50; Sat, 10 Mar 2018 01:20:05 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751930AbeCJJS5 (ORCPT + 99 others); Sat, 10 Mar 2018 04:18:57 -0500 Received: from mail.skyhub.de ([5.9.137.197]:48598 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750829AbeCJJSz (ORCPT ); Sat, 10 Mar 2018 04:18:55 -0500 X-Virus-Scanned: Nedap ESD1 at mail.skyhub.de Received: from mail.skyhub.de ([127.0.0.1]) by localhost (blast.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 7Vf4JyQ9C9_t; Sat, 10 Mar 2018 10:18:54 +0100 (CET) Received: from pd.tnic (p200300EC2BD4CE00596C69A920A9793D.dip0.t-ipconnect.de [IPv6:2003:ec:2bd4:ce00:596c:69a9:20a9:793d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 257001EC00EA; Sat, 10 Mar 2018 10:18:54 +0100 (CET) Date: Sat, 10 Mar 2018 10:18:38 +0100 From: Borislav Petkov To: "Maciej S. Szmigiero" Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86/microcode/AMD: check microcode file sanity before loading it Message-ID: <20180310091838.GA8261@pd.tnic> References: <34e9d679-2eca-90cf-9a95-3864f0be060e@maciej.szmigiero.name> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <34e9d679-2eca-90cf-9a95-3864f0be060e@maciej.szmigiero.name> User-Agent: Mutt/1.9.3 (2018-01-21) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Mar 10, 2018 at 01:34:45AM +0100, Maciej S. Szmigiero wrote: > Currently, it is very easy to make the AMD microcode update driver crash > or spin on a malformed microcode file since it does very little > consistency checking on data loaded from such file. Sorry but if one has enough permissions to install malformed microcode, crashing the loader is the least of your problems. IOW, I don't see the justification for the unnecessary complication with all those checks. Thx. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.