[PATCH 3.16.y-ckt 108/142] ubi: Fix out of bounds write in volume update code

[Luis Henriques]

3.16.7-ckt26 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Richard Weinberger <richard at nod.at>

commit e4f6daac20332448529b11f09388f1d55ef2084c upstream.

ubi_start_leb_change() allocates too few bytes.
ubi_more_leb_change_data() will write up to req->upd_bytes +
ubi->min_io_size bytes.

Signed-off-by: Richard Weinberger <richard at nod.at>
Reviewed-by: Boris Brezillon <boris.brezillon at free-electrons.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/mtd/ubi/upd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/ubi/upd.c b/drivers/mtd/ubi/upd.c
index 2a1b6e037e1a..0134ba32a057 100644
--- a/drivers/mtd/ubi/upd.c
+++ b/drivers/mtd/ubi/upd.c
@@ -193,7 +193,7 @@ int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 	vol->changing_leb = 1;
 	vol->ch_lnum = req->lnum;
 
-	vol->upd_buf = vmalloc(req->bytes);
+	vol->upd_buf = vmalloc(ALIGN((int)req->bytes, ubi->min_io_size));
 	if (!vol->upd_buf)
 		return -ENOMEM;