From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932242AbWGRPVy (ORCPT ); Tue, 18 Jul 2006 11:21:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932262AbWGRPVy (ORCPT ); Tue, 18 Jul 2006 11:21:54 -0400 Received: from coyote.holtmann.net ([217.160.111.169]:45279 "EHLO mail.holtmann.net") by vger.kernel.org with ESMTP id S932242AbWGRPVy (ORCPT ); Tue, 18 Jul 2006 11:21:54 -0400 Subject: Re: Bad ext3/nfs DoS bug From: Marcel Holtmann To: James <20@madingley.org> Cc: linux-kernel@vger.kernel.org In-Reply-To: <20060718145614.GA27788@circe.esc.cam.ac.uk> References: <20060717130128.GA12832@circe.esc.cam.ac.uk> <1153209318.26690.1.camel@localhost> <20060718145614.GA27788@circe.esc.cam.ac.uk> Content-Type: text/plain Date: Tue, 18 Jul 2006 17:22:16 +0200 Message-Id: <1153236136.10006.5.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.7.4 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi James, > > so I used your exploit and I could reproduce it on every 2.6 kernel, I > > tried so far. > > That must have been a lot of fscks. it wasn't that many. For some obvious reasons I only tested the RHEL and Fedora kernels and vanilla plus stable series. > > However with a 2.4 kernel I see the error messages, but it > > doesn't get remounted read-only. Did you run tests with 2.4 kernels? > > no, I don't have any to hand, but someone is preparing one > now. Is NFS subtree checking on by default in 2.4? I haven't checked within the code, but the manual page exports(5) states subtree checking as being on by default. And it doesn't mention any difference to 2.4 kernels. What is the reason behind your question? Does disabling subtree checking changes something? Regards Marcel