From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: symlinks with permissions Date: Fri, 30 Oct 2009 19:35:59 +0100 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 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 To: "Eric W. Biederman" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org 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