[PATCH 3.10 41/54] UBI: Validate data_size

Greg Kroah-Hartman
2015-10-18T02:55:11Z

From: Richard Weinberger <richard@nod.at>

commit 281fda27673f833a01d516658a64d22a32c8e072 upstream.

Make sure that data_size is less than LEB size.
Otherwise a handcrafted UBI image is able to trigger
an out of bounds memory access in ubi_compare_lebs().

Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: David Gstir <david@sigma-star.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/mtd/ubi/io.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -931,6 +931,11 @@ static int validate_vid_hdr(const struct
goto bad;
}

+ if (data_size > ubi->leb_size) {
+ ubi_err("bad data_size");
+ goto bad;
+ }
+
if (vol_type == UBI_VID_STATIC) {
/*
* Although from high-level point of view static volumes may