Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:29799 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756354Ab3H3OZT (ORCPT ); Fri, 30 Aug 2013 10:25:19 -0400 Date: Fri, 30 Aug 2013 10:25:03 -0400 From: "J. Bruce Fields" To: Toralf =?iso-8859-1?Q?F=F6rster?= Cc: "J. Bruce Fields" , richard -rw- weinberger , Linux NFS mailing list , "user-mode-linux-devel@lists.sourceforge.net" , Linux Kernel , Jan Kara , linux-ext4@vger.kernel.org Subject: Re: [uml-devel] Issues with a rather unusual configured NFS server Message-ID: <20130830142503.GA31129@pad.fieldses.org> References: <52075E01.7030506@gmx.de> <20130812143640.GF4596@quack.suse.cz> <20130813215313.GH17781@fieldses.org> <20130827180655.GE14809@fieldses.org> <521E318C.7040401@gmx.de> <20130829133010.GA14773@fieldses.org> <5220A7E2.1070704@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 In-Reply-To: <5220A7E2.1070704@gmx.de> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Fri, Aug 30, 2013 at 04:10:42PM +0200, Toralf F?rster wrote: > On 08/29/2013 03:30 PM, J. Bruce Fields wrote: > > On Thu, Aug 29, 2013 at 11:57:45AM +0200, richard -rw- weinberger wrote: > >> On Wed, Aug 28, 2013 at 7:21 PM, Toralf F?rster wrote: > >>> On 08/27/2013 08:06 PM, J. Bruce Fields wrote: > >>>> On Tue, Aug 13, 2013 at 05:53:14PM -0400, bfields wrote: > >>>>> On Mon, Aug 12, 2013 at 04:36:40PM +0200, Jan Kara wrote: > >>>>>> On Sun 11-08-13 11:48:49, Toralf F?rster wrote: > >>>>>>> so that the server either crashes (if it is a user mode linux image) or at least its reboot functionality got broken > >>>>>>> - if the NFS server is hammered with scary NFS calls using a fuzzy tool running at a remote NFS client under a non-privileged user id. > >>>>>>> > >>>>>>> It can re reproduced, if > >>>>>>> - the NFS share is an EXT3 or EXT4 directory > >>>>>>> - and it is created at file located at tempfs and mounted via loop device > >>>>>>> - and the NFS server is forced to umount the NFS share > >>>>>>> - and the server forced to restart the NSF service afterwards > >>>>>>> - and trinity is used > >>>>>>> > >>>>>>> I could find a scenario for an automated bisect. 2 times it brought this commit > >>>>>>> commit 68a3396178e6688ad7367202cdf0af8ed03c8727 > >>>>>>> Author: J. Bruce Fields > >>>>>>> Date: Thu Mar 21 11:21:50 2013 -0400 > >>>>>>> > >>>>>>> nfsd4: shut down more of delegation earlier > >>>>> > >>>>> Thanks for the report. I think I see the problem--after this commit > >>>>> nfs4_set_delegation() failures result in nfs4_put_delegation being > >>>>> called, but nfs4_put_delegation doesn't free the nfs4_file that has > >>>>> already been set by alloc_init_deleg(). > >>>>> > >>>>> Let me think about how to fix that.... > >>>> > >>>> Sorry for the slow response--can you check whether this fixes the > >>>> problem? > >>>> > >>> Yes. > >>> > >>> With the attached patch the problem can't be reproduced any longer with > >>> the prepared test case and current git kernels. > >> > >> BTW: Is nobody else fuzz testing NFS? > > > > I don't know. Toralf's reports are the only ones I recall off the top > > of my head, but I may have forgotten others. > > > > well, 7255e71 and 3c50ba8 I'd say. I don't know any 3c50ba8. 0c7c3e67 "nfsd4: don't close read-write opens too soon" and 64a817cf "nfsd4: reject "negative" acl lengths" are two other serious bugs found by your testing. I don't recall fuzz testing results from anyone else, but as I say I may have forgotten. --b.