Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750745AbWAJARK (ORCPT ); Mon, 9 Jan 2006 19:17:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751302AbWAJARK (ORCPT ); Mon, 9 Jan 2006 19:17:10 -0500 Received: from soundwarez.org ([217.160.171.123]:55466 "EHLO soundwarez.org") by vger.kernel.org with ESMTP id S1750745AbWAJARJ (ORCPT ); Mon, 9 Jan 2006 19:17:09 -0500 Date: Tue, 10 Jan 2006 01:17:01 +0100 From: Kay Sievers To: Matthew Garrett Cc: Andreas Gruenbacher , Matthew Garrett , Andrew Morton , linux-kernel@vger.kernel.org, Linus Torvalds Subject: Re: [patch 0/2] Tmpfs acls Message-ID: <20060110001701.GA25690@vrfy.org> References: <200601090023.16956.agruen@suse.de> <200601100059.47317.agruen@suse.de> <20060110000758.GA22399@srcf.ucam.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060110000758.GA22399@srcf.ucam.org> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1533 Lines: 34 On Tue, Jan 10, 2006 at 12:07:58AM +0000, Matthew Garrett wrote: > On Tue, Jan 10, 2006 at 12:59:46AM +0100, Andreas Gruenbacher wrote: > > On Monday 09 January 2006 00:34, Matthew Garrett wrote: > > > Hmm. Do you have any infrastructure for revoking open file descriptors > > > when a user logs out? > > > > Open file descriptors have nothing to do with it. The device permissions are > > set by different pam modules on different distributions (pam_console, > > pam_resmgr). > > Right. But what stops a user writing an application that opens a device, > hangs around after the user logs out and then provides access to the > user when logged in remotely? > > Handwavy problem scenario - user A logs in, is given access to the > soundcard. Starts running a program that when given appropriate signals > will record from the system microphone. Logs out. Waits for user B, who > he suspects is having an affair with his wife, and then monitors any > conversations that user B has. That can be solved in the user session handling and not in the kernel. > ACLs on their own don't seem to solve > this any more than just statically assigning group membership to users. Sure, they do. Unlike silly group memberships, the system can provide ressources to "local" users only. Kay - 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/