[3.16.y-ckt stable] Patch "dm log userspace: fix memory leak in dm_ulog_tfr_init failure path" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    dm log userspace: fix memory leak in dm_ulog_tfr_init failure path

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt2.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 91f81da889d95204c3b5014aa131e7a74ab7e145 Mon Sep 17 00:00:00 2001
From: Alexey Khoroshilov <khoroshilov at ispras.ru>
Date: Wed, 1 Oct 2014 22:58:35 +0200
Subject: dm log userspace: fix memory leak in dm_ulog_tfr_init failure path

commit 56ec16cb1e1ce46354de8511eef962a417c32c92 upstream.

If cn_add_callback() fails in dm_ulog_tfr_init(), it does not
deallocate prealloced memory but calls cn_del_callback().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov at ispras.ru>
Reviewed-by: Jonathan Brassow <jbrassow at redhat.com>
Signed-off-by: Mike Snitzer <snitzer at redhat.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/md/dm-log-userspace-transfer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/dm-log-userspace-transfer.c b/drivers/md/dm-log-userspace-transfer.c
index b428c0ae63d5..39ad9664d397 100644
--- a/drivers/md/dm-log-userspace-transfer.c
+++ b/drivers/md/dm-log-userspace-transfer.c
@@ -272,7 +272,7 @@ int dm_ulog_tfr_init(void)

 	r = cn_add_callback(&ulog_cn_id, "dmlogusr", cn_ulog_callback);
 	if (r) {
-		cn_del_callback(&ulog_cn_id);
+		kfree(prealloced_cn_msg);
 		return r;
 	}

--
2.1.0