From: Richard Weinberger <richard@nod.at>
Date: Tue, 22 Sep 2015 21:58:07 +0000 (+0200)
Subject: UBI: Validate data_size
X-Git-Tag: v4.1.11~31
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=189c815c3535412f80f3cc628149aa8dda50b3d2;p=users%2Fjedix%2Flinux-maple.git

UBI: Validate data_size

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>
---

diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index 5bbd1f094f4e3..1fc23e48fe8e4 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -926,6 +926,11 @@ 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