dsp: q6usm: Check size of payload before access

Check size of payload array before access in q6usm_callback.

Change-Id: Id0c85209a053f9dfdb53133aeb6b2510ecf18eb8
Signed-off-by: Vatsal Bucha <[email protected]>

dsp/q6usm.c

@@ -556,6 +556,11 @@ static int32_t q6usm_callback(struct apr_client_data *data, void *priv)
 	}
 
 	if (data->opcode == APR_BASIC_RSP_RESULT) {
+		if (data->payload_size < (2 * sizeof(uint32_t))) {
+			pr_err("%s: payload has invalid size[%d]\n", __func__,
+			       data->payload_size);
+			return -EINVAL;
+		}
 		/* status field check */
 		if (payload[1]) {
 			pr_err("%s: wrong response[%d] on cmd [%d]\n",
@@ -619,6 +624,12 @@ static int32_t q6usm_callback(struct apr_client_data *data, void *priv)
 
 		opcode = Q6USM_EVENT_READ_DONE;
 		spin_lock_irqsave(&port->dsp_lock, dsp_flags);
+		if (data->payload_size <
+		    (sizeof(uint32_t)*(READDONE_IDX_STATUS + 1))) {
+			pr_err("%s: Invalid payload size for READDONE[%d]\n",
+			       __func__, data->payload_size);
+			return -EINVAL;
+		}
 		if (payload[READDONE_IDX_STATUS]) {
 			pr_err("%s: wrong READDONE[%d]; token[%d]\n",
 			       __func__,
@@ -665,6 +676,12 @@ static int32_t q6usm_callback(struct apr_client_data *data, void *priv)
 		struct us_port_data *port = &usc->port[IN];
 
 		opcode = Q6USM_EVENT_WRITE_DONE;
+		if (data->payload_size <
+		    (sizeof(uint32_t)*(WRITEDONE_IDX_STATUS + 1))) {
+			pr_err("%s: Invalid payload size for WRITEDONE[%d]\n",
+			       __func__, data->payload_size);
+			return -EINVAL;
+		}
 		if (payload[WRITEDONE_IDX_STATUS]) {
 			pr_err("%s: wrong WRITEDONE_IDX_STATUS[%d]\n",
 			       __func__,