From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261975AbVELNtT (ORCPT ); Thu, 12 May 2005 09:49:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261978AbVELNtT (ORCPT ); Thu, 12 May 2005 09:49:19 -0400 Received: from e32.co.us.ibm.com ([32.97.110.130]:22716 "EHLO e32.co.us.ibm.com") by vger.kernel.org with ESMTP id S261975AbVELNtJ (ORCPT ); Thu, 12 May 2005 09:49:09 -0400 Date: Thu, 12 May 2005 08:47:34 -0500 From: serue@us.ibm.com To: Eric Van Hensbergen Cc: Jamie Lokier , Ram , Miklos Szeredi , 7eggert@gmx.de, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, smfrench@austin.rr.com, hch@infradead.org Subject: Re: [RCF] [PATCH] unprivileged mount/umount Message-ID: <20050512134734.GA17062@serge.austin.ibm.com> References: <20050511170700.GC2141@mail.shareable.org> <1115840139.6248.181.camel@localhost> <20050511212810.GD5093@mail.shareable.org> <1115851333.6248.225.camel@localhost> <20050512010215.GB8457@mail.shareable.org> <20050512064514.GA12315@mail.shareable.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.8i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Quoting Eric Van Hensbergen (ericvh@gmail.com): > Let's focus on baby steps first, and to me that's: > a) get rid of holes that allow users to traverse out of a chroot jail > by using the creation of private name spaces (is anyone working on > this, did I miss a patch?) I have tested doing clone(CLONE_NEWNS); chdir(/some_jail_dir); pivot_root(., tmp) umount2(tmp, MNT_DETACH) chroot(.) which appears to prevent escapes from chroot jails. So unless my tests were insufficient, we don't need additional kernel support. We can just use something like chroot_ns.c from www.sf.net/projects/linux-jail/. > b) make CLONE_NEWNS (and any other name space creation mechanisms such > as the proposed unshare system call) available to normal users > c) Get the unshare system call adopted as it seems to be generally useful > d) Get Miklos' unprivileged mount/umount patch adopted in mainline and I'd say e) Work towards the shared namespaces, which are really one of the main reasons not to use namespaces right now. I know this work is being done, so this isn't so much a request for the shared namespaces, as just a reminder that this will be one of the major pieces of functionality to consider along with the ones you listed. thanks, -serge