smart_amp_test: bound channel counts to platform max

The sample component took its channel counts from the streams and used
them to index the platform-sized channel map without bounds. Reject
counts above the platform maximum.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>

Author: lrgirdwo

src/samples/audio/smart_amp_test_ipc3.c

@@ -518,6 +518,16 @@ static int smart_amp_prepare(struct comp_dev *dev)
 
 	sad->in_channels = audio_stream_get_channels(&sad->source_buf->stream);
 
+	/* out_channels bounds the processing loop that indexes the
+	 * PLATFORM_MAX_CHANNELS-sized channel map, so reject a larger count
+	 */
+	if (sad->out_channels > PLATFORM_MAX_CHANNELS ||
+	    sad->in_channels > PLATFORM_MAX_CHANNELS) {
+		comp_err(dev, "invalid channel count, in %u out %u",
+			 sad->in_channels, sad->out_channels);
+		return -EINVAL;
+	}
+
 	if (sad->feedback_buf) {
 		audio_stream_set_channels(&sad->feedback_buf->stream,
 					  sad->config.feedback_channels);