From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751071AbWD3JPE (ORCPT ); Sun, 30 Apr 2006 05:15:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751073AbWD3JPE (ORCPT ); Sun, 30 Apr 2006 05:15:04 -0400 Received: from zakalwe.fi ([80.83.5.154]:45064 "EHLO zakalwe.fi") by vger.kernel.org with ESMTP id S1751071AbWD3JPD (ORCPT ); Sun, 30 Apr 2006 05:15:03 -0400 Date: Sun, 30 Apr 2006 09:15:01 +0000 From: Heikki Orsila To: Alistair John Strachan Cc: Mark Rosenstand , linux-kernel@vger.kernel.org Subject: Re: World writable tarballs Message-ID: <20060430091501.GA19566@zakalwe.fi> References: <1146356286.10953.7.camel@hammer> <200604300148.12462.s0348365@sms.ed.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <200604300148.12462.s0348365@sms.ed.ac.uk> User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Apr 30, 2006 at 01:48:12AM +0100, Alistair John Strachan wrote: > There's no need to repeatedly discuss it. I think there is. Sorry for wasting bandwidth. It's a big security hole deliberately caused by the kernel people (files in the tar ball have og+w, so it's not problem in roots umask or tar). Real security needs _simplicity_ but current file modes require unnecessary _tricks_ for admins. There should be nothing against untarring files as root. In this case it makes sense too, because only the tar balls are crypto signed, not the individual files inside the tar ball, so root can conveniently just verify the crypto signature and untar the file without any race conditions or trusting other users. The only real alternative is to create an _unnecessary_ trusted user to do tar ball handling. PS. this file permission bug almost bit me. People make errors and this one is potentially a big privilege escalation, because it potentially turns normal application bugs into root privileges. -- Heikki Orsila Barbie's law: heikki.orsila@iki.fi "Math is hard, let's go shopping!" http://www.iki.fi/shd