From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: silent semantic changes with reiser4 Date: Thu, 26 Aug 2004 17:57:44 +0200 Sender: linux-fsdevel-owner@vger.kernel.org Message-ID: <20040826155744.GA4250@lst.de> References: <20040824202521.GA26705@lst.de> <412CEE38.1080707@namesys.com> <20040825200859.GA16345@lst.de> <20040825203516.GB4688@backtop.namesys.com> <20040825205149.GA17654@lst.de> <412DA2CF.2030204@namesys.com> <20040826124119.GA431@lst.de> <20040826134812.GB5733@mail.shareable.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christoph Hellwig , Hans Reiser , Alex Zarochentsev , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Alexander Lyamin aka FLX , Linus Torvalds , ReiserFS List Return-path: Received: from verein.lst.de ([213.95.11.210]:51417 "EHLO mail.lst.de") by vger.kernel.org with ESMTP id S269156AbUHZP5z (ORCPT ); Thu, 26 Aug 2004 11:57:55 -0400 To: Jamie Lokier Content-Disposition: inline In-Reply-To: <20040826134812.GB5733@mail.shareable.org> List-Id: linux-fsdevel.vger.kernel.org On Thu, Aug 26, 2004 at 02:48:12PM +0100, Jamie Lokier wrote: > > the current reiser4 semantics break that and as soon as you're having a > > world-writeable (e.g. /tmp) dir on it and someone is doing an opendir > > on it he's lost. > > How does the current reiser4 semantics break that? > > In a reiser4 filesystem, a file _is_ a directory. > opendir() is supposed to succeed on it. > > There's bound to be some security issue, but I'm not sure what you're > getting at with /tmp. What sort of sort of security problem arises > with a world-writeable directory such as /tmp, that cannot arise with > the standard fs semantics? Actually you are right on that issue because it would open the device/fifo as directory and not device/fifo (in fact I'd had to look at the code again to see whether they actually do this only for files or also for special files)