[PATCH v1] mtd: ubi: Release device reference on busy detach

[Yuho Choi]

ubi_detach_mtd_dev() obtains a device reference through ubi_get_device()
before checking whether the UBI device is busy. The busy return path drops
ubi->ref_count but leaves the device reference held, so the device object
cannot be released after a later detach.

Drop the device reference before returning -EBUSY.

Fixes: 7e84c961b2eb ("mtd: ubi: introduce pre-removal notification for UBI volumes")
Signed-off-by: Yuho Choi <dbgh9129 at gmail.com>
---
 drivers/mtd/ubi/build.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 674ad87809df..ee6ce4471b25 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -1105,6 +1105,7 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
 	ubi->ref_count -= 1;
 	if (ubi->ref_count) {
 		if (!anyway) {
+			put_device(&ubi->dev);
 			spin_unlock(&ubi_devices_lock);
 			return -EBUSY;
 		}
-- 
2.43.0