[PATCH] ubi: block: fix null-pointer-dereference in ubiblock_create()

[linan666 at huaweicloud.com]

From: Li Nan <linan122 at huawei.com>

If idr_alloc() fails, dev->gd will be put after goto out_cleanup_disk in
ubiblock_create(), but dev->gd has not been assigned yet at this time, and
accessing it will trigger a null-pointer-dereference issue. Fix it by put
gd directly.

Signed-off-by: Li Nan <linan122 at huawei.com>
---
 drivers/mtd/ubi/block.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
index 309a42aeaa4c..654bd7372cd8 100644
--- a/drivers/mtd/ubi/block.c
+++ b/drivers/mtd/ubi/block.c
@@ -434,7 +434,7 @@ int ubiblock_create(struct ubi_volume_info *vi)
 	list_del(&dev->list);
 	idr_remove(&ubiblock_minor_idr, gd->first_minor);
 out_cleanup_disk:
-	put_disk(dev->gd);
+	put_disk(gd);
 out_free_tags:
 	blk_mq_free_tag_set(&dev->tag_set);
 out_free_dev:
-- 
2.39.2