Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934615AbXK2W66 (ORCPT ); Thu, 29 Nov 2007 17:58:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932857AbXK2W6s (ORCPT ); Thu, 29 Nov 2007 17:58:48 -0500 Received: from cantor2.suse.de ([195.135.220.15]:33278 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933553AbXK2W6r (ORCPT ); Thu, 29 Nov 2007 17:58:47 -0500 To: Alan Cox Cc: Christoph Hellwig , Jan Engelhardt , Greg KH , Jon Masters , Valdis.Kletnieks@vt.edu, Al Viro , Casey Schaufler , "Tvrtko A. Ursulin" , linux-kernel@vger.kernel.org Subject: Re: Out of tree module using LSM From: Andi Kleen References: <416908.77038.qm@web36613.mail.mud.yahoo.com> <20071128164613.GA21815@infradead.org> <25290.1196273705@turing-police.cc.vt.edu> <20071128183040.GW8181@ftp.linux.org.uk> <20071129003840.GA22530@kroah.com> <20071129010753.GA19106@kroah.com> <1196354172.6473.52.camel@perihelion> <20071129164746.GB9664@kroah.com> <20071129165731.GA30719@infradead.org> <20071129172740.2515fa75@the-village.bc.nu> Date: Thu, 29 Nov 2007 23:58:44 +0100 In-Reply-To: <20071129172740.2515fa75@the-village.bc.nu> (Alan Cox's message of "Thu\, 29 Nov 2007 17\:27\:40 +0000") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1595 Lines: 40 Alan Cox writes: > > The simple case is > open > write cathedral and bazaar in some order > close > process -> label eric_t> > > open (eric_t) - SELinux "no" > > > Anyone smart will then write it out of order and keep the file open, or That would assume Eric already has a program running on your system optimized to inject his works in a obfuscated way. And if he has a program running he can do nearly everything already. You already lost the game. The normal case Tvrtko et.al. are trying to handle would be more the work getting downloaded from somewhere or read from a usb stick using normal programs like web browsers or file managers who don't do any out of order writing tricks and other obfuscation. Important exception might be things like BitTorrent who write out of order or parallel downloaders to cheat TCP congestion control. Or simply tar+gzip with automatic depacking in desktops. There are probably more and it's probably tricky but it is not a "need to handle arbitary nastiness by a determined attacker" situation. Anyways I'm not saying that pattern matching is a useful security measure (just the interaction with compression and encryption makes it very dubious), but if you're talking hypothetically you should at least look closely at the hypothetical use cases @) -Andi - 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/