From: Richard Weinberger <richard@nod.at>
Date: Sun, 21 Feb 2016 09:53:03 +0000 (+0100)
Subject: ubi: Fix out of bounds write in volume update code
X-Git-Tag: Ubuntu-5.4-5.4.0-11.14~10641^2
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=e4f6daac20332448529b11f09388f1d55ef2084c;p=mirror_ubuntu-focal-kernel.git

ubi: Fix out of bounds write in volume update code

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.

Cc: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---

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;