Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750871AbWJDT3Q (ORCPT ); Wed, 4 Oct 2006 15:29:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750860AbWJDT3Q (ORCPT ); Wed, 4 Oct 2006 15:29:16 -0400 Received: from mail.aknet.ru ([82.179.72.26]:65288 "EHLO mail.aknet.ru") by vger.kernel.org with ESMTP id S1750865AbWJDT3P (ORCPT ); Wed, 4 Oct 2006 15:29:15 -0400 Message-ID: <45240BF0.4050400@aknet.ru> Date: Wed, 04 Oct 2006 23:30:56 +0400 From: Stas Sergeev User-Agent: Thunderbird 1.5.0.7 (X11/20060913) MIME-Version: 1.0 To: Linux kernel Subject: Re: [patch] remove MNT_NOEXEC check for PROT_EXEC mmaps References: <4516B721.5070801@redhat.com> <45198395.4050008@aknet.ru> <1159396436.3086.51.camel@laptopd505.fenrus.org> <451E3C0C.10105@aknet.ru> <1159887682.2891.537.camel@laptopd505.fenrus.org> <45229A99.6060703@aknet.ru> <1159899820.2891.542.camel@laptopd505.fenrus.org> <4522AEA1.5060304@aknet.ru> <1159900934.2891.548.camel@laptopd505.fenrus.org> <4522B4F9.8000301@aknet.ru> <20061003210037.GO20982@devserv.devel.redhat.com> In-Reply-To: <20061003210037.GO20982@devserv.devel.redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1433 Lines: 34 Hello. David Wagner wrote: >>/That's obviously possible, but I'd feel safer having/ >>/"noexec" on *every* user-writable partition./ > But why would you "feel" safer? And why should the Linux kernel care > about how people "feel"? I am more wondering why should I answer this, esp. since you do not even care to CC me. > What threat, exactly, are you trying to > defend against? What's your threat model? Am I supposed to explain why I want to prevent an attacker from executing the exploit he happened to copy to one of the user-writable mounts of mine? > so you say it is not a library and not a binary. So what is it that you > are maping in as executable, and why do you think it is reasonable to > ask the Linux kernel to allow you to execute it, if it lives on a noexec > partition? Quick answer is: because not having the exec permission (chmod -x file) doesn't prevent you from mapping that file "noexec", and that's correct, not bug. The more detailed discussion have already happened, and I'd like to leave MAP_SHARED aside for a time. Please tell me how your logic applies to MAP_PRIVATE instead, because right now MAP_PRIVATE is affected the same way the MAP_SHARED is. - 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/