From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753178Ab1AEXM2 (ORCPT ); Wed, 5 Jan 2011 18:12:28 -0500 Received: from kroah.org ([198.145.64.141]:50720 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753131Ab1AEXGS (ORCPT ); Wed, 5 Jan 2011 18:06:18 -0500 X-Mailbox-Line: From gregkh@clark.site Wed Jan 5 15:03:24 2011 Message-Id: <20110105230324.304662136@clark.site> User-Agent: quilt/0.48-11.2 Date: Wed, 05 Jan 2011 15:00:27 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Chuck Lever , Trond Myklebust Subject: [09/49] NFS: Fix panic after nfs_umount() In-Reply-To: <20110105230438.GA26241@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Chuck Lever commit 5b362ac3799ff4225c40935500f520cad4d7ed66 upstream. After a few unsuccessful NFS mount attempts in which the client and server cannot agree on an authentication flavor both support, the client panics. nfs_umount() is invoked in the kernel in this case. Turns out nfs_umount()'s UMNT RPC invocation causes the RPC client to write off the end of the rpc_clnt's iostat array. This is because the mount client's nrprocs field is initialized with the count of defined procedures (two: MNT and UMNT), rather than the size of the client's proc array (four). The fix is to use the same initialization technique used by most other upper layer clients in the kernel. Introduced by commit 0b524123, which failed to update nrprocs when support was added for UMNT in the kernel. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=24302 BugLink: http://bugs.launchpad.net/bugs/683938 Reported-by: Stefan Bader Tested-by: Stefan Bader Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- fs/nfs/mount_clnt.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/fs/nfs/mount_clnt.c +++ b/fs/nfs/mount_clnt.c @@ -503,13 +503,13 @@ static struct rpc_procinfo mnt3_procedur static struct rpc_version mnt_version1 = { .number = 1, - .nrprocs = 2, + .nrprocs = ARRAY_SIZE(mnt_procedures), .procs = mnt_procedures, }; static struct rpc_version mnt_version3 = { .number = 3, - .nrprocs = 2, + .nrprocs = ARRAY_SIZE(mnt3_procedures), .procs = mnt3_procedures, };