Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932886AbZJ3SgD (ORCPT ); Fri, 30 Oct 2009 14:36:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932870AbZJ3SgD (ORCPT ); Fri, 30 Oct 2009 14:36:03 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:39753 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932861AbZJ3SgC (ORCPT ); Fri, 30 Oct 2009 14:36:02 -0400 Date: Fri, 30 Oct 2009 19:35:59 +0100 From: Pavel Machek To: "Eric W. Biederman" 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 Message-ID: <20091030183559.GF7008@elf.ucw.cz> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1413 Lines: 37 Hi! > > Basically, that follow link should behave as dup(), not as open(). > > There are reasons why an open is an open here. I don't remember the > details but I found the archive of that conversation once. Maybe it was > just technical limitations of the time. That would be really really useful to bring > >> 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). > 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 :-). Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/