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blk-mq: Fix refcounting leak in __blk_mq_register_dev()

PATCH In review Dan Carpenter 2 participants 2 messages Sep 5, 2020 – Sep 7, 2020

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#0 lore raw

PATCH 1/1 blk-mq: Fix refcounting leak in __blk_mq_register_dev()

There is a kobject_add() hidden in the call to kobject_add().

	ret = kobject_add(q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
                                      ^^^^^^^^^^^^^^^^^^^^^^^

It needs to be release on the error path.

Fixes 320ae51feed5 ("blk-mq: new multi-queue block IO queueing mechanism")
---
 block/blk-mq-sysfs.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
block/blk-mq-sysfs.c +3 -3
index 062229395a50..5a63659163c1 100644
@@ -321,7 +321,7 @@ int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
 
 	ret = kobject_add(q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
 	if (ret < 0)
-		goto out;
+		goto out_kobj;
 
 	kobject_uevent(q->mq_kobj, KOBJ_ADD);
 
@@ -333,8 +333,7 @@ int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
 
 	q->mq_sysfs_init_done = true;
 
-out:
-	return ret;
+	return 0;
 
 unreg:
 	while (--i >= 0)
@@ -342,6 +341,7 @@ int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
 
 	kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
 	kobject_del(q->mq_kobj);
+out_kobj:
 	kobject_put(&dev->kobj);
 	return ret;
 }
Signature · 1 line
2.28.0
Reviewed-by on v1 1/1
#1 lore raw
Quoted 47 lines · Dan Carpenter

There is a kobject_add() hidden in the call to kobject_add().

	ret = kobject_add(q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
                                      ^^^^^^^^^^^^^^^^^^^^^^^

It needs to be release on the error path.

Fixes 320ae51feed5 ("blk-mq: new multi-queue block IO queueing mechanism")
---
 block/blk-mq-sysfs.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
block/blk-mq-sysfs.c +3 -3
index 062229395a50..5a63659163c1 100644
@@ -321,7 +321,7 @@ int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
 
 	ret = kobject_add(q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
 	if (ret < 0)
-		goto out;
+		goto out_kobj;
 
 	kobject_uevent(q->mq_kobj, KOBJ_ADD);
 
@@ -333,8 +333,7 @@ int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
 
 	q->mq_sysfs_init_done = true;
 
-out:
-	return ret;
+	return 0;
 
 unreg:
 	while (--i >= 0)
@@ -342,6 +341,7 @@ int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
 
 	kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
 	kobject_del(q->mq_kobj);
+out_kobj:
 	kobject_put(&dev->kobj);
 	return ret;
 }
Signature · 1 line
2.28.0

Looks good fix:

Signature · 1 line
Ming