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 <stable@xxxxxxxxxxxxxxx> know about it. >From a24221dca1868101c9b4b5adde4a6a5b1a3a64a7 Mon Sep 17 00:00:00 2001 From: Jeff Layton <jlayton@xxxxxxxxxxxxxxx> Date: Wed, 24 Jun 2015 12:10:23 -0400 Subject: nfs: fix potential credential leak in ff_layout_update_mirror_cred From: Jeff Layton <jlayton@xxxxxxxxxxxxxxx> 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 <jeff.layton@xxxxxxxxxxxxxxx> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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@xxxxxxxxxxxxxxx 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 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html