Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751339AbXAIMPy (ORCPT ); Tue, 9 Jan 2007 07:15:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751346AbXAIMPx (ORCPT ); Tue, 9 Jan 2007 07:15:53 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.31.123]:41580 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751339AbXAIMPx (ORCPT ); Tue, 9 Jan 2007 07:15:53 -0500 Date: Tue, 9 Jan 2007 13:15:52 +0100 From: Jan Kara To: Josef Sipek Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, hch@infradead.org, viro@ftp.linux.org.uk, torvalds@osdl.org, mhalcrow@us.ibm.com, David Quigley , Erez Zadok Subject: Re: [PATCH 01/24] Unionfs: Documentation Message-ID: <20070109121552.GA1260@atrey.karlin.mff.cuni.cz> References: <1168229596580-git-send-email-jsipek@cs.sunysb.edu> <1168229596875-git-send-email-jsipek@cs.sunysb.edu> <20070108111852.ee156a90.akpm@osdl.org> <20070108231524.GA1269@filer.fsl.cs.sunysb.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070108231524.GA1269@filer.fsl.cs.sunysb.edu> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1184 Lines: 29 > On Mon, Jan 08, 2007 at 11:18:52AM -0800, Andrew Morton wrote: > > On Sun, 7 Jan 2007 23:12:53 -0500 > > "Josef 'Jeff' Sipek" wrote: > > > > > Any such change can cause Unionfs to oops, or stay > > > silent and even RESULT IN DATA LOSS. > > > > With a rather rough user interface ;) > > That statement is meant to scare people away from modifying the lower fs :) > I tortured unionfs quite a bit, and it can oops but it takes some effort. But isn't it then potential DOS? If you happen to union two filesystems and an untrusted user has write access to both original filesystem and the union, then you say he'd be able to produce oops? That does not sound very secure to me... And if any secure use of unionfs requires limitting access to the original trees, then I think it's a good reason to implement it in unionfs itself. Just my 2 cents. Honza -- Jan Kara SuSE CR Labs - 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/