Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-vb0-f41.google.com ([209.85.212.41]:48708 "EHLO mail-vb0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752244Ab3H2J5q convert rfc822-to-8bit (ORCPT ); Thu, 29 Aug 2013 05:57:46 -0400 MIME-Version: 1.0 In-Reply-To: <521E318C.7040401@gmx.de> References: <52075E01.7030506@gmx.de> <20130812143640.GF4596@quack.suse.cz> <20130813215313.GH17781@fieldses.org> <20130827180655.GE14809@fieldses.org> <521E318C.7040401@gmx.de> Date: Thu, 29 Aug 2013 11:57:45 +0200 Message-ID: Subject: Re: [uml-devel] Issues with a rather unusual configured NFS server From: richard -rw- weinberger To: =?ISO-8859-1?Q?Toralf_F=F6rster?= Cc: "J. Bruce Fields" , Linux NFS mailing list , "J. Bruce Fields" , "user-mode-linux-devel@lists.sourceforge.net" , Linux Kernel , Jan Kara , linux-ext4@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: 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? Or are these bugs just more likely to hit on UML? This is not the first NFS issue found by Toralf using UML and Trinity. -- Thanks, //richard