Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965282AbXATPLO (ORCPT ); Sat, 20 Jan 2007 10:11:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965280AbXATPLO (ORCPT ); Sat, 20 Jan 2007 10:11:14 -0500 Received: from 69-100-st.zelcom.ru ([80.92.100.69]:1954 "EHLO etherstorm.feelingofgreen.ru" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S965282AbXATPLN (ORCPT ); Sat, 20 Jan 2007 10:11:13 -0500 X-Greylist: delayed 2028 seconds by postgrey-1.27 at vger.kernel.org; Sat, 20 Jan 2007 10:11:13 EST Date: Sat, 20 Jan 2007 17:37:22 +0300 Message-ID: <87y7nxvk65.wl@betelheise.deep.net> From: Samium Gromoff <_deepfire@feelingofgreen.ru> To: linux-kernel@vger.kernel.org Subject: [PATCH] Undo some of the pseudo-security madness User-Agent: Wanderlust/2.15.5 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.8 (=?ISO-8859-4?Q?Shij=F2?=) APEL/10.6 Emacs/23.0.51 (i486-pc-linux-gnu) MULE/5.0 (SAKAKI) X-Face: "P-:w!.&Hdk.h~~pT`!Q%H6;/8Cce^m&%vIn"W-SXb4h88dCgwD\_}N5:\}lowY2gxg0u^wVO*L\$C@MvBDRTmh/=,468w{W{OTc$kfq5O9Y!`pd+N}SMHrN+Gs>jXe5}}EL`cRbc0^_0cZ-}M\b~55I;Qe$1uL8M`M`82<_%CQ(GwLk."M>zBLn:-u>n,$kjH`~Uo[pH`08#\G!GVMd`%7![m9]*w5PMts4@m>=;lX41Z90N MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1509 Lines: 39 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. Secondly, there also are valid reasons to want those applications to be setuid root. Like poking hardware. So, here we have a buffer-overflow protection technique, which does not actually protect against buffer overflows[1], breaking valid applications. I suggest getting rid of it. --- include/linux/personality.h 2007-01-20 17:31:01.000000000 +0300 +++ include/linux-sane/personality.h 2007-01-20 17:32:50.000000000 +0300 @@ -40,7 +40,7 @@ * Security-relevant compatibility flags that must be * cleared upon setuid or setgid exec: */ -#define PER_CLEAR_ON_SETID (READ_IMPLIES_EXEC|ADDR_NO_RANDOMIZE) +#define PER_CLEAR_ON_SETID (READ_IMPLIES_EXEC) /* * Personality types. Signed-off-by: Samium Gromoff <_deepfire@feelinfofgreen.ru> [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 - 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/