Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757847Ab1FFT0L (ORCPT ); Mon, 6 Jun 2011 15:26:11 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:39954 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757376Ab1FFT0J (ORCPT ); Mon, 6 Jun 2011 15:26:09 -0400 Date: Mon, 6 Jun 2011 21:25:44 +0200 From: Ingo Molnar To: pageexec@freemail.hu Cc: Linus Torvalds , Andi Kleen , Andy Lutomirski , x86@kernel.org, Thomas Gleixner , linux-kernel@vger.kernel.org, Jesper Juhl , Borislav Petkov , Andrew Morton , Arjan van de Ven , Jan Beulich , richard -rw- weinberger , Mikael Pettersson , Brian Gerst , Louis Rilling , Valdis.Kletnieks@vt.edu Subject: Re: [PATCH v5 9/9] x86-64: Add CONFIG_UNSAFE_VSYSCALLS to feature-removal-schedule Message-ID: <20110606192544.GA28947@elte.hu> References: <4DECAE68.16683.1203EBBB@pageexec.freemail.hu> <20110606144414.GA30348@elte.hu> <4DED239B.8177.13CDBA86@pageexec.freemail.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4DED239B.8177.13CDBA86@pageexec.freemail.hu> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1967 Lines: 53 * pageexec@freemail.hu wrote: > [...] it goes like 'I am not willing to do A because it would help > script kiddies but I'd rather do B that would help script kiddies'. > with A = 'disclose security bugs' and B = 'keep the last roadblock > that prevents full ASLR'. No, that's wrong, the logic goes like this: if i do A then it has X1 advantages and Y1 disadvantages. if i do B then it has X2 advantages and Y2 disadvantages. The Y1 and Y2 set of disadvantages can both include "making it easier for script kiddies" but the sets of advantages and disadvantages can also include MANY OTHER considerations, making the decision unique in each case. To translate it to this specific case (extremely simplifed, so please don't nit-pick that my descriptions of advantages and disadvantages are not precise nor complete): A) "i put a zero day exploit and a CVE code into a changelog" Advantages: - it describes the problem more fully Disadvantages: - it makes it easier for people (including script kiddies) do harm faster - creates a false, misleading category for "security bugs" B) "i obfuscate the vsyscall page" Advantages: - it makes it statistically harder for people (including script kiddies) to do harm Disadvantages: - it reduces the incentive to fix *real* security bugs - complicates the code Do you see how A) and B) are not equivalent at all? Different cases, different attributes, different probabilities and different considerations. > but it's very simple logic Ingo. Please drop the condescending tone, i think it should be clear to you by now that i have a good basis to disagree with you. Thanks, Ingo -- 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/