[PATCH 3.2 57/62] ubi: Fix out of bounds write in volume update code

[Ben Hutchings]

3.2.79-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Richard Weinberger <richard@xxxxxx>

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@xxxxxx>
Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/mtd/ubi/upd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/mtd/ubi/upd.c
+++ b/drivers/mtd/ubi/upd.c
@@ -197,7 +197,7 @@ int ubi_start_leb_change(struct ubi_devi
 	vol->ch_lnum = req->lnum;
 	vol->ch_dtype = req->dtype;
 
-	vol->upd_buf = vmalloc(req->bytes);
+	vol->upd_buf = vmalloc(ALIGN((int)req->bytes, ubi->min_io_size));
 	if (!vol->upd_buf)
 		return -ENOMEM;