From 281fda27673f833a01d516658a64d22a32c8e072 Mon Sep 17 00:00:00 2001
From: Richard Weinberger <richard@nod.at>
Date: Tue, 22 Sep 2015 23:58:07 +0200
Subject: UBI: Validate data_size

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@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: David Gstir <david@sigma-star.at>

diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index 5bbd1f0..1fc23e4 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
-- 
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