From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH] sysfs: Don't allow the creation of symlinks we can't remove Date: Thu, 8 Jul 2010 14:19:30 -0700 Message-ID: <20100708211930.GA15385@kroah.com> References: <20100621150826.762ac9f2.akpm@linux-foundation.org> <20100621222938.GA20583@suse.de> <20100621231058.GA1066@suse.de> <20100622035631.GA3755@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Greg KH , Andrew Morton , "Rafael J. Wysocki" , "Maciej W. Rozycki" , Kay Sievers , Johannes Berg , netdev To: "Eric W. Biederman" Return-path: Received: from kroah.org ([198.145.64.141]:58535 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756874Ab0GHVTe (ORCPT ); Thu, 8 Jul 2010 17:19:34 -0400 Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Jul 08, 2010 at 09:31:24AM -0700, Eric W. Biederman wrote: > > Recently my tagged sysfs support revealed a flaw in the device core > that a few rare drivers are running into such that we don't always put > network devices in a class subdirectory named net/. > > Since we are not creating the class directory the network devices wind > up in a non-tagged directory, but the symlinks to the network devices > from /sys/class/net are in a tagged directory. All of which works > until we go to remove or rename the symlink. When we remove or rename > a symlink we look in the namespace of the target of the symlink. > Since the target of the symlink is in a non-tagged sysfs directory we > don't have a namespace to look in, and we fail to remove the symlink. > > Detect this problem up front and simply don't create symlinks we won't > be able to remove later. This prevents symlink leakage and fails in > a much clearer and more understandable way. With this patch, how does the existing code fail as the drivers aren't fixed up? I like this change, just worried it will cause problems if it gets into .35, without your RFC patch. Will it? thanks, greg k-h