[PATCH] blkcg:Fix memory leaks in blkg_conf_prep()

[Wu Bo]

From: Wu Bo <wubo40@xxxxxxxxxx>

If a call of the function blkg_lookup_check() failed,
we should be release the previously allocated block group 
before jumping to the lable 'fail_unlock' in the implementation of 
the function blkg_conf_prep().

Suggested-by: Markus Elfring <Markus.Elfring@xxxxxx>
Signed-off-by: Wu Bo <wubo40@xxxxxxxxxx>

---
V2: omit the source code quotation from 
    the change description

---
 block/blk-cgroup.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 930212c..afeb769 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -682,6 +682,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
 		blkg = blkg_lookup_check(pos, pol, q);
 		if (IS_ERR(blkg)) {
 			ret = PTR_ERR(blkg);
+			blkg_free(new_blkg);
 			goto fail_unlock;
 		}
 
-- 
1.8.3.1