Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751367AbWI1Ecc (ORCPT ); Thu, 28 Sep 2006 00:32:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751373AbWI1Ecc (ORCPT ); Thu, 28 Sep 2006 00:32:32 -0400 Received: from mail.aknet.ru ([82.179.72.26]:44043 "EHLO mail.aknet.ru") by vger.kernel.org with ESMTP id S1751367AbWI1Ecb (ORCPT ); Thu, 28 Sep 2006 00:32:31 -0400 Message-ID: <451B5096.6020205@aknet.ru> Date: Thu, 28 Sep 2006 08:33:26 +0400 From: Stas Sergeev User-Agent: Thunderbird 1.5.0.7 (X11/20060913) MIME-Version: 1.0 To: Hugh Dickins Cc: Alan Cox , Ulrich Drepper , Valdis.Kletnieks@vt.edu, Arjan van de Ven , Linux kernel Subject: Re: [patch] remove MNT_NOEXEC check for PROT_EXEC MAP_PRIVATE mmaps References: <45150CD7.4010708@aknet.ru> <451555CB.5010006@aknet.ru> <1159037913.24572.62.camel@localhost.localdomain> <45162BE5.2020100@aknet.ru> <1159106032.11049.12.camel@localhost.localdomain> <45169C0C.5010001@aknet.ru> <4516A8E3.4020100@redhat.com> <4516B2C8.4050202@aknet.ru> <4516B721.5070801@redhat.com> <451ACE29.4080005@aknet.ru> In-Reply-To: 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: 1371 Lines: 31 Hello. Hugh Dickins wrote: > since executables are typically mapped MAP_PRIVATE, I suspect > your patch will simply break mmap's intended MNT_NOEXEC check. The one with ld.so you mean? But its a user-space issue, I haven't seen anyone claiming the opposite (and you even explicitly confirmed it is). > I think you need to face up to the fact that "noexec" > doesn't suit your mount, and just leave it at that. But noone have answered this question: Which configuration is more secure - the one where all the user-writable fs are mounted with "noexec" (in old sense of noexec), or the one without "noexec" at all because I should no longer use it here and there (actually, everywhere)? > But I do concede that I'm reluctant to present that patch Alan > encouraged, adding a matching MNT_NOEXEC check to mprotect: it > would be consistent, and I do like consistency, but in this case > fear that change in behaviour may cause new userspace breakage. I can't think of a single real-life example where it will break something over whatever is broken already by the mmap check. But I am not encouraging such a change of course. - 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/