[PATCH v2 51/62] UBI: Validate data_size

[Teresa Remmet]

From: Richard Weinberger <richard at nod.at>

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().

Cc: stable at vger.kernel.org
Signed-off-by: Richard Weinberger <richard at nod.at>
Reviewed-by: David Gstir <david at sigma-star.at>
Signed-off-by: Teresa Remmet <t.remmet at phytec.de>
---
 drivers/mtd/ubi/io.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index bb38b79..655ab50 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -618,6 +618,11 @@ static int validate_vid_hdr(const struct ubi_device *ubi,
 		goto bad;
 	}
 
+	if (data_size > ubi->leb_size) {
+		ubi_err(ubi, "bad data_size");
+		goto bad;
+	}
+
 	if (vol_type == UBI_VID_STATIC) {
 		/*
 		 * Although from high-level point of view static volumes may
-- 
1.9.1