firmware: cs_dsp: Return error if block header overflows file

Return an error from cs_dsp_power_up() if a block header is longer
than the amount of data left in the file.

The previous code in cs_dsp_load() and cs_dsp_load_coeff() would loop
while there was enough data left in the file for a valid region. This
protected against overrunning the end of the file data, but it didn't
abort the file processing with an error.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Fixes: f6bc909e7673 ("firmware: cs_dsp: add driver to support firmware loading on Cirrus Logic DSPs")
Link: https://patch.msgid.link/20240627141432.93056-3-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/firmware/cirrus/cs_dsp.c b/drivers/firmware/cirrus/cs_dsp.c
index 6eca62d31e206e98964971b1d35d2113a6ed431e..47cf91be99a1364fe8ef43a42384b38d2fa2ab3c 100644 (file)
--- a/drivers/firmware/cirrus/cs_dsp.c
+++ b/drivers/firmware/cirrus/cs_dsp.c
@@ -1444,8 +1444,13 @@ static int cs_dsp_load(struct cs_dsp *dsp, const struct firmware *firmware,
        cs_dsp_dbg(dsp, "%s: timestamp %llu\n", file,
                   le64_to_cpu(footer->timestamp));
 
-       while (pos < firmware->size &&
-              sizeof(*region) < firmware->size - pos) {
+       while (pos < firmware->size) {
+               /* Is there enough data for a complete block header? */
+               if (sizeof(*region) > firmware->size - pos) {
+                       ret = -EOVERFLOW;
+                       goto out_fw;
+               }
+
                region = (void *)&(firmware->data[pos]);
                region_name = "Unknown";
                reg = 0;
@@ -2133,8 +2138,13 @@ static int cs_dsp_load_coeff(struct cs_dsp *dsp, const struct firmware *firmware
        pos = le32_to_cpu(hdr->len);
 
        blocks = 0;
-       while (pos < firmware->size &&
-              sizeof(*blk) < firmware->size - pos) {
+       while (pos < firmware->size) {
+               /* Is there enough data for a complete block header? */
+               if (sizeof(*blk) > firmware->size - pos) {
+                       ret = -EOVERFLOW;
+                       goto out_fw;
+               }
+
                blk = (void *)(&firmware->data[pos]);
 
                type = le16_to_cpu(blk->type);