[PATCH] UBI: Handle empty string in verify_mkvol_req()

[Richard Weinberger]

Currently it's possible to create a volume without a name.
E.g:
ubimkvol -n 32 -s 2MiB -t static /dev/ubi0 -N ""

After that vtbl_check() will always fail because it does not permit
empty strings.

Cc: <stable at vger.kernel.org>
Signed-off-by: Richard Weinberger <richard at nod.at>
---
 drivers/mtd/ubi/cdev.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c
index 3320a50..ad76592 100644
--- a/drivers/mtd/ubi/cdev.c
+++ b/drivers/mtd/ubi/cdev.c
@@ -632,6 +632,9 @@ static int verify_mkvol_req(const struct ubi_device *ubi,
 	if (req->alignment != 1 && n)
 		goto bad;
 
+	if (!req->name[0] || !req->name_len)
+		goto bad;
+
 	if (req->name_len > UBI_VOL_NAME_MAX) {
 		err = -ENAMETOOLONG;
 		goto bad;
-- 
1.7.7.3