[MTD] fix use after free in register_mtd_blktrans

Reported-by: Dan Carpenter <error27@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 1409f01406f6..4109e0bb94f5 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -382,11 +382,12 @@ int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
         tr->blkcore_priv->thread = kthread_run(mtd_blktrans_thread, tr,
                         "%sd", tr->name);
         if (IS_ERR(tr->blkcore_priv->thread)) {
+                int ret = PTR_ERR(tr->blkcore_priv->thread);
                 blk_cleanup_queue(tr->blkcore_priv->rq);
                 unregister_blkdev(tr->major, tr->name);
                 kfree(tr->blkcore_priv);
                 mutex_unlock(&mtd_table_mutex);
-                return PTR_ERR(tr->blkcore_priv->thread);
+                return ret;
         }
 
         INIT_LIST_HEAD(&tr->devs);