From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45467 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752078AbbGaTiI (ORCPT ); Fri, 31 Jul 2015 15:38:08 -0400 Subject: Patch "nfs: fix potential credential leak in ff_layout_update_mirror_cred" has been added to the 4.1-stable tree To: jlayton@poochiereds.net, gregkh@linuxfoundation.org, jeff.layton@primarydata.com, trond.myklebust@primarydata.com Cc: , From: Date: Fri, 31 Jul 2015 12:38:05 -0700 Message-ID: <143837148565241@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled nfs: fix potential credential leak in ff_layout_update_mirror_cred to the 4.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nfs-fix-potential-credential-leak-in-ff_layout_update_mirror_cred.patch and it can be found in the queue-4.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From a24221dca1868101c9b4b5adde4a6a5b1a3a64a7 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Wed, 24 Jun 2015 12:10:23 -0400 Subject: nfs: fix potential credential leak in ff_layout_update_mirror_cred From: Jeff Layton commit a24221dca1868101c9b4b5adde4a6a5b1a3a64a7 upstream. If we have two tasks racing to update a mirror's credentials, then they can end up leaking one (or more) sets of credentials. The first task will set mirror->cred and then the second task will just overwrite it. Use a cmpxchg to ensure that the creds are only set once. If we get to the point where we would set mirror->cred and find that they're already set, then we just release the creds that were just found. Signed-off-by: Jeff Layton Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- fs/nfs/flexfilelayout/flexfilelayoutdev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/nfs/flexfilelayout/flexfilelayoutdev.c +++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c @@ -324,7 +324,8 @@ static int ff_layout_update_mirror_cred( __func__, PTR_ERR(cred)); return PTR_ERR(cred); } else { - mirror->cred = cred; + if (cmpxchg(&mirror->cred, NULL, cred)) + put_rpccred(cred); } } return 0; Patches currently in stable-queue which might be from jlayton@poochiereds.net are queue-4.1/nfs-increase-size-of-exchange_id-name-string-buffer.patch queue-4.1/nfs-always-update-creds-in-mirror-even-when-we-have-an-already-connected-ds.patch queue-4.1/nfs-fix-potential-credential-leak-in-ff_layout_update_mirror_cred.patch