ASoC: wm_adsp: Fix validation of firmware and coeff lengths

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>
Cc: stable@vger.kernel.org
This commit is contained in:
Ben Hutchings 2017-12-08 16:15:20 +00:00 committed by Mark Brown
parent 4fbd8d194f
commit 50dd2ea8ef
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@ -1733,7 +1733,7 @@ static int wm_adsp_load(struct wm_adsp *dsp)
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;
@ -1782,8 +1782,8 @@ static int wm_adsp_load(struct wm_adsp *dsp)
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,
@ -2253,7 +2253,7 @@ static int wm_adsp_load_coeff(struct wm_adsp *dsp)
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);
@ -2327,8 +2327,8 @@ static int wm_adsp_load_coeff(struct wm_adsp *dsp)
}
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,