Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751169AbXAUCQK (ORCPT ); Sat, 20 Jan 2007 21:16:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751141AbXAUCQK (ORCPT ); Sat, 20 Jan 2007 21:16:10 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:60776 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751154AbXAUCQI (ORCPT ); Sat, 20 Jan 2007 21:16:08 -0500 Subject: Re: [PATCH] Undo some of the pseudo-security madness From: Arjan van de Ven To: Samium Gromoff <_deepfire@feelingofgreen.ru> Cc: linux-kernel@vger.kernel.org In-Reply-To: <87y7nxvk65.wl@betelheise.deep.net> References: <87y7nxvk65.wl@betelheise.deep.net> Content-Type: text/plain Organization: Intel International BV Date: Sun, 21 Jan 2007 03:16:04 +0100 Message-Id: <1169345764.3055.935.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.8.2.1 (2.8.2.1-2.fc6) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1489 Lines: 35 On Sat, 2007-01-20 at 17:37 +0300, Samium Gromoff wrote: > This patch removes the dropping of ADDR_NO_RANDOMIZE upon execution of setuid > binaries. > > Why? The answer consists of two parts: > > Firstly, there are valid applications which need an unadulterated memory map. > Some of those which do their memory management, like lisp systems (like SBCL). > They try to achieve this by setting ADDR_NO_RANDOMIZE and reexecuting themselves. this is a ... funny way of achieving this if an application for some reason wants some fixed address for a piece of memory there are other ways to do that.... (but to some degree all apps that can't take randomization broken; for example a glibc upgrade on a system will also move the address space around by virtue of being bigger or smaller etc etc) > [1]. See the excellent, 'Hackers Hut' by Andries Brouwer, which describes > how AS randomisation can be got around by the means of linux-gate.so.1 got a URL to this? If this is exploiting the fact that the vdso is at a fixed spot... it's no longer the case since quite a while. -- if you want to mail me at work (you don't), use arjan (at) linux.intel.com Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org - 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/