audio: check for NULL buffers in case of invalid IPC flows

src/audio/asrc/asrc.c

@@ -452,11 +452,14 @@ static int asrc_dai_find(struct comp_dev *dev, struct comp_data *cd)
 		/* In push mode check if sink component is DAI */
 		do {
 			sinkb = comp_dev_get_first_data_consumer(dev);
+			if (!sinkb) {
+				comp_err(asrc_dev, "At end: NULL buffer, no DAI found.");
+				return -EINVAL;
+			}
 
 			dev = comp_buffer_get_sink_component(sinkb);
-
 			if (!dev) {
-				comp_err(asrc_dev, "At end, no DAI found.");
+				comp_err(asrc_dev, "At end: NULL device, no DAI found.");
 				return -EINVAL;
 			}
 
@@ -470,11 +473,14 @@ static int asrc_dai_find(struct comp_dev *dev, struct comp_data *cd)
 		/* In pull mode check if source component is DAI */
 		do {
 			sourceb = comp_dev_get_first_data_producer(dev);
+			if (!sourceb) {
+				comp_err(asrc_dev, "At beginning: NULL buffer, no DAI found.");
+				return -EINVAL;
+			}
 
 			dev = comp_buffer_get_source_component(sourceb);
-
 			if (!dev) {
-				comp_err(asrc_dev, "At beginning, no DAI found.");
+				comp_err(asrc_dev, "At beginning: NULL device, no DAI found.");
 				return -EINVAL;
 			}
 

src/audio/selector/selector.c

@@ -344,8 +344,14 @@ static int selector_trigger(struct comp_dev *dev, int cmd)
 	comp_dbg(dev, "selector_trigger()");
 
 	sourceb = comp_dev_get_first_data_producer(dev);
+	if (!sourceb) {
+		comp_err(dev, "source disconnected");
+		return -ENODEV;
+	}
 
 	ret = comp_set_state(dev, cmd);
+	if (ret == COMP_STATUS_STATE_ALREADY_SET)
+		ret = 0;
 
 	/* TODO: remove in the future after adding support for case when
 	 * kpb_init_draining() and kpb_draining_task() are interrupted by

src/ipc/ipc3/helper.c

@@ -562,7 +562,13 @@ int ipc_buffer_free(struct ipc *ipc, uint32_t buffer_id)
 	 * core, the free must be run in the context of the active
 	 * pipeline.
 	 */
-	active_comp = sink_active ? sink : source;
+	if (sink_active)
+		active_comp = sink;
+	else if (source_active)
+		active_comp = source;
+	else
+		active_comp = NULL;
+
 	if (active_comp) {
 		core = active_comp->ipc_config.core;