From 46ffccd753f5a350265b8650a83ba51972a5a0cf Mon Sep 17 00:00:00 2001
From: Jeremy Compostella <jeremy.compostella@intel.com>
Date: Thu, 8 Sep 2022 13:47:35 -0700
Subject: [PATCH] util/ifittool: Fix buffer overflow with padded microcode
 patches

Some microcode patches are padded with zeros, which make
parse_microcode_blob() read beyond the end of the buffer.

BRANCH=firmware-brya-14505.B
BUG=b:245380705
TEST=No segmentation fault with a padded microcode patch

Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Change-Id: Id9c5fb6c1e264f3f5137d29201b9021c72d78fdd
Reviewed-on: https://review.coreboot.org/c/coreboot/+/67460
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Cliff Huang <cliff.huang@intel.com>
Reviewed-by: Nick Vaccaro <nvaccaro@google.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
---
 util/cbfstool/fit.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/util/cbfstool/fit.c b/util/cbfstool/fit.c
index 89b0fd28d9..7f8218a745 100644
--- a/util/cbfstool/fit.c
+++ b/util/cbfstool/fit.c
@@ -297,7 +297,8 @@ parse_microcode_blob(struct cbfs_image *image,
 		uint32_t total_size = mcu_header->total_size ?: 2048;
 
 		/* Quickly sanity check a prospective microcode update. */
-		if (total_size < sizeof(*mcu_header))
+		if (total_size < sizeof(*mcu_header) ||
+		    total_size > file_length)
 			break;
 
 		/* FIXME: Should the checksum be validated? */