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

Kamal Mostafa kamal at canonical.com
Tue Oct 21 20:09:28 UTC 2014

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-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:


This patch is scheduled to be released in version

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

For more information about the 3.13.y.z tree, see



>From 4cf4433f7d1eb98bc185988a159e41abd1764c52 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: Kamal Mostafa <kamal 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 08d9a20..c69d0b7 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;


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