Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933082AbZJ3XDq (ORCPT ); Fri, 30 Oct 2009 19:03:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933012AbZJ3XDo (ORCPT ); Fri, 30 Oct 2009 19:03:44 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:60162 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933008AbZJ3XDn (ORCPT ); Fri, 30 Oct 2009 19:03:43 -0400 To: Pavel Machek Cc: Trond Myklebust , Jan Kara , "J. Bruce Fields" , "Serge E. Hallyn" , kernel list , linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, jamie@shareable.org Subject: Re: symlinks with permissions References: <20091026174631.GD7233@duck.suse.cz> <1256579869.8576.7.camel@heimdal.trondhjem.org> <20091025093604.GA1501@ucw.cz> <20091028081653.GA18290@elf.ucw.cz> <20091028210323.GA4159@elf.ucw.cz> <20091029110344.GA1517@ucw.cz> <20091030183559.GF7008@elf.ucw.cz> From: ebiederm@xmission.com (Eric W. Biederman) Date: Fri, 30 Oct 2009 16:03:36 -0700 In-Reply-To: <20091030183559.GF7008@elf.ucw.cz> (Pavel Machek's message of "Fri\, 30 Oct 2009 19\:35\:59 +0100") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in02.mta.xmission.com;;;ip=76.21.114.89;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 76.21.114.89 X-SA-Exim-Mail-From: ebiederm@xmission.com X-SA-Exim-Version: 4.2.1 (built Thu, 25 Oct 2007 00:26:12 +0000) X-SA-Exim-Scanned: No (on in02.mta.xmission.com); Unknown failure Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1386 Lines: 36 Pavel Machek writes: >> >> I certainly am not interested in debugging or maintaining the stacking >> >> inode code that would be necessary to close this theoretical corner >> >> case. There are much more real bugs that need attention. >> > >> > But if we can get trivial 10-liner, that should be acceptable, right? >> >> How many linux shell scripts and other applications that use /dev/fd/N >> or /proc/self/fd/N will you be breaking? > > Zero. (Well unless someone is exploiting it in wild). There are other differences like different offsets etc that may matter. >> Closing a theoretical security hole at the expense of breaking real >> applications is a show stopper. > > I don't plan to remove /proc/*/fd; but I would like it to behave like > dup(). > > (I still hope some security team does work for me :-). Seriously turning this into dup is about 20 lines of code in follow link. Just look at the open intent in the nameidata. nfs should have an exampled of using the open intent somewhere. I bet you will get a lot more traction and discussion if you write a basic mostly working version of the patch. Eric -- 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/