From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266677AbUHIOwN (ORCPT ); Mon, 9 Aug 2004 10:52:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266657AbUHIOjv (ORCPT ); Mon, 9 Aug 2004 10:39:51 -0400 Received: from vivaldi.madbase.net ([81.173.6.10]:743 "HELO vivaldi.madbase.net") by vger.kernel.org with SMTP id S266677AbUHIOge (ORCPT ); Mon, 9 Aug 2004 10:36:34 -0400 Date: Mon, 9 Aug 2004 10:36:28 -0400 (EDT) From: Eric Lammerts X-X-Sender: eric@vivaldi.madbase.net To: Joerg Schilling cc: James.Bottomley@steeleye.com, axboe@suse.de, linux-kernel@vger.kernel.org Subject: Re: PATCH: cdrecord: avoiding scsi device numbering for ide devices In-Reply-To: <200408091224.i79COp69009736@burner.fokus.fraunhofer.de> Message-ID: References: <200408091224.i79COp69009736@burner.fokus.fraunhofer.de> 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 On Mon, 9 Aug 2004, Joerg Schilling wrote: > >From: Eric Lammerts > > >On Fri, 6 Aug 2004, Joerg Schilling wrote: > >> The CAM interface (which is from the SCSI standards group) > >> usually is implemeted in a way that applications open /dev/cam and > >> later supply bus, target and lun in order to get connected > >> to any device on the system that talks SCSI. > >> > >> Let me repeat: If you believe that this is a bad idea, give very > >> good reasons. > > >With this interface, how do you grant non-root users access to a CD > >writer, but prevent them from directly accessing a SCSI harddisk? > > On Linux, it is impossible to run cdrecord without root privilleges. > Make cdrecord suid root, it has been audited.... > > On Solaris, there is ACLs, RBAC & getppriv() / setppriv() Interesting. How do you use those to grant someone access to a particular CD writer device behind /dev/cam _without_ at the same time granting them access to other SCSI devices too? I know that it's possible with a trusted binary (like cdrecord) that's setuid root, or that gets some priviledges some other way, but if that is the _only_ way, then that's a flaw in the CAM interface. On Linux you can simply change permissions on the CD writer's device node to allow non-root users to burn CDs. Eric