From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753910AbXDVArj (ORCPT ); Sat, 21 Apr 2007 20:47:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753905AbXDVArj (ORCPT ); Sat, 21 Apr 2007 20:47:39 -0400 Received: from cs.columbia.edu ([128.59.16.20]:58801 "EHLO cs.columbia.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753883AbXDVAri (ORCPT ); Sat, 21 Apr 2007 20:47:38 -0400 Message-ID: <462AB061.2070104@cs.columbia.edu> Date: Sat, 21 Apr 2007 20:46:25 -0400 From: Shaya Potter User-Agent: Thunderbird 2.0.0.0 (X11/20070326) MIME-Version: 1.0 To: Andrew Morton CC: Miklos Szeredi , serue@us.ibm.com, viro@ftp.linux.org.uk, linuxram@us.ibm.com, ebiederm@xmission.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, containers@lists.osdl.org Subject: Re: [patch 7/8] allow unprivileged mounts References: <20070420102532.385211890@szeredi.hu> <20070420102652.075606533@szeredi.hu> <20070421005513.e230aa88.akpm@linux-foundation.org> In-Reply-To: <20070421005513.e230aa88.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-PerlMx-Spam: Gauge=IIIIIII, Probability=7%, X-Seen-By filter1.cs.columbia.edu Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > On Fri, 20 Apr 2007 12:25:39 +0200 Miklos Szeredi wrote: > >> Define a new fs flag FS_SAFE, which denotes, that unprivileged >> mounting of this filesystem may not constitute a security problem. >> >> Since most filesystems haven't been designed with unprivileged >> mounting in mind, a thorough audit is needed before setting this flag. > > Practically speaking, is there any realistic likelihood that any filesystem > apart from FUSE will ever use this? Would it be interesting to support mounting of external file systems (be it USB, NFS or whatever) in a way that automatically forces it to ignore suid and devices (which are already mount time options)? The question I guess is, how much do you gain over a setuid program (hack?) that can handle this?