From: Alexey Khoroshilov <khoroshilov@ispras.ru>
Date: Wed, 1 Oct 2014 20:58:35 +0000 (+0200)
Subject: dm log userspace: fix memory leak in dm_ulog_tfr_init failure path
X-Git-Tag: submit/tizen/20160422.055611~1^2~99^2~11^2~266
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0f693a712421a8ba2b7b84d513bae72a816e7096;p=sdk%2Femulator%2Femulator-kernel.git

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@ispras.ru>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/md/dm-log-userspace-transfer.c b/drivers/md/dm-log-userspace-transfer.c
index 08d9a207259a..c69d0b787746 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;
 	}