[PATCH 4.4 65/74] ubi: Fix out of bounds write in volume update code

[Greg Kroah-Hartman]

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

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

From: Richard Weinberger <rich...@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 <rich...@nod.at>
Reviewed-by: Boris Brezillon <boris.brezil...@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 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
@@ -193,7 +193,7 @@ int ubi_start_leb_change(struct ubi_devi
        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;