Patch "ASoC: wm_adsp: Fix validation of firmware and coeff lengths" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    ASoC: wm_adsp: Fix validation of firmware and coeff lengths

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     asoc-wm_adsp-fix-validation-of-firmware-and-coeff-lengths.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 50dd2ea8ef67a1617e0c0658bcbec4b9fb03b936 Mon Sep 17 00:00:00 2001
From: Ben Hutchings <ben.hutchings@codethink.co.uk>
Date: Fri, 8 Dec 2017 16:15:20 +0000
Subject: ASoC: wm_adsp: Fix validation of firmware and coeff lengths

From: Ben Hutchings <ben.hutchings@codethink.co.uk>

commit 50dd2ea8ef67a1617e0c0658bcbec4b9fb03b936 upstream.

The checks for whether another region/block header could be present
are subtracting the size from the current offset.  Obviously we should
instead subtract the offset from the size.

The checks for whether the region/block data fit in the file are
adding the data size to the current offset and header size, without
checking for integer overflow.  Rearrange these so that overflow is
impossible.

Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Tested-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 sound/soc/codecs/wm_adsp.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -1465,7 +1465,7 @@ static int wm_adsp_load(struct wm_adsp *
 		 le64_to_cpu(footer->timestamp));
 
 	while (pos < firmware->size &&
-	       pos - firmware->size > sizeof(*region)) {
+	       sizeof(*region) < firmware->size - pos) {
 		region = (void *)&(firmware->data[pos]);
 		region_name = "Unknown";
 		reg = 0;
@@ -1526,8 +1526,8 @@ static int wm_adsp_load(struct wm_adsp *
 			 regions, le32_to_cpu(region->len), offset,
 			 region_name);
 
-		if ((pos + le32_to_cpu(region->len) + sizeof(*region)) >
-		    firmware->size) {
+		if (le32_to_cpu(region->len) >
+		    firmware->size - pos - sizeof(*region)) {
 			adsp_err(dsp,
 				 "%s.%d: %s region len %d bytes exceeds file length %zu\n",
 				 file, regions, region_name,
@@ -1992,7 +1992,7 @@ static int wm_adsp_load_coeff(struct wm_
 
 	blocks = 0;
 	while (pos < firmware->size &&
-	       pos - firmware->size > sizeof(*blk)) {
+	       sizeof(*blk) < firmware->size - pos) {
 		blk = (void *)(&firmware->data[pos]);
 
 		type = le16_to_cpu(blk->type);
@@ -2066,8 +2066,8 @@ static int wm_adsp_load_coeff(struct wm_
 		}
 
 		if (reg) {
-			if ((pos + le32_to_cpu(blk->len) + sizeof(*blk)) >
-			    firmware->size) {
+			if (le32_to_cpu(blk->len) >
+			    firmware->size - pos - sizeof(*blk)) {
 				adsp_err(dsp,
 					 "%s.%d: %s region len %d bytes exceeds file length %zu\n",
 					 file, blocks, region_name,


Patches currently in stable-queue which might be from ben.hutchings@codethink.co.uk are

queue-4.9/asoc-wm_adsp-fix-validation-of-firmware-and-coeff-lengths.patch