Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261865AbVEWI7P (ORCPT ); Mon, 23 May 2005 04:59:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261853AbVEWI7P (ORCPT ); Mon, 23 May 2005 04:59:15 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:35739 "EHLO amd.ucw.cz") by vger.kernel.org with ESMTP id S261865AbVEWI7J (ORCPT ); Mon, 23 May 2005 04:59:09 -0400 Date: Mon, 23 May 2005 10:58:52 +0200 From: Pavel Machek To: Reiner Sailer Cc: linux-kernel@vger.kernel.org, linux-security-module@mail.wirex.com, Kylene@us.ibm.com, Emilyr@us.ibm.com, Toml@us.ibm.com Subject: Re: [PATCH 2 of 4] ima: related Makefile compile order change and Readme Message-ID: <20050523085852.GA1942@elf.ucw.cz> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1697 Lines: 43 Hi! > > > +Limitations: IMA does not detect corruption of software once it is > > > +loaded into main memory. Instead, it indicates known vulnerabilities > > > +in such software (e.g., buffer overflow) by securely identifying the > > > +software at load-time. Only executable files (binaries, libraries, > > > +kernel modules) are measured by default. However, IMA offers a > > > +sysfs-interface that allows applications to instruct the kernel to > > > +measure files that they have opened. > > > > What is it good for, then? So I have to put my backdoor into script, > > not into an executable... > > Scripts can be measured as well (from the user space). > > For example, equipping the bash shell with 5-10 lines of code, bash > initiates IMA measurements on scripts and files that are sourced into bash before > they are "executed" by bash. This way, startup scripts and executed scripts can > be logged as measurements and the measuremnt list will include > them. Well, for this to be usefull, you'd have to split files into two categories: 1) files that do not change 2) files that can not compromise your security. I guess that /etc/shadow *has to change*, and it still can compromise your system security. Same with basch scripts; you can make bash checksum its script, but when user modifies his first script, you'll detect system as "compromised". I guess it can work... but I don't see how it can work in Linux. Pavel - 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/