diff --git a/src/audio/kpb.c b/src/audio/kpb.c
index 9dca05630da1..71fdca29e73e 100644
--- a/src/audio/kpb.c
+++ b/src/audio/kpb.c
@@ -1033,18 +1033,19 @@ static void kpb_micselect_copy16(struct comp_buffer *sink,
 {
 	struct audio_stream *istream = &source->stream;
 	struct audio_stream *ostream = &sink->stream;
-	uint16_t ch;
+	uint32_t ch;
 	size_t i;
 
 	AE_SETCBEGIN0(audio_stream_get_addr(ostream));
 	AE_SETCEND0(audio_stream_get_end_addr(ostream));
 
-	buffer_stream_invalidate(source, size);
+	const size_t samples_per_chan = size / (sizeof(ae_int16) * micsel_channels);
+
+	buffer_stream_invalidate(source, samples_per_chan * in_channels * sizeof(ae_int16));
 	const ae_int16 *in_ptr = audio_stream_get_rptr(istream);
 	ae_int16x4 d16 = AE_ZERO16();
 	const size_t in_offset = in_channels * sizeof(ae_int16);
 	const size_t out_offset = micsel_channels * sizeof(ae_int16);
-	const size_t samples_per_chan = size / (sizeof(uint16_t) * micsel_channels);
 	ae_int16 *out_ptr;
 
 	for (ch = 0; ch < micsel_channels; ch++) {
@@ -1066,19 +1067,20 @@ static void kpb_micselect_copy32(struct comp_buffer *sink,
 {
 	struct audio_stream *istream = &source->stream;
 	struct audio_stream *ostream = &sink->stream;
-	uint16_t ch;
+	uint32_t ch;
 	size_t i;
 
 	AE_SETCBEGIN0(audio_stream_get_addr(ostream));
 	AE_SETCEND0(audio_stream_get_end_addr(ostream));
 
-	buffer_stream_invalidate(source, size);
+	const size_t samples_per_chan = size / (sizeof(ae_int32) * micsel_channels);
+
+	buffer_stream_invalidate(source, samples_per_chan * in_channels * sizeof(ae_int32));
 
 	const ae_int32 *in_ptr = audio_stream_get_rptr(istream);
 	ae_int32x2 d32 = AE_ZERO32();
 	const size_t in_offset = in_channels * sizeof(ae_int32);
 	const size_t out_offset = micsel_channels * sizeof(ae_int32);
-	const size_t samples_per_chan = size / (sizeof(uint32_t) * micsel_channels);
 	ae_int32 *out_ptr;
 
 	for (ch = 0; ch < micsel_channels; ch++) {
@@ -1100,14 +1102,14 @@ static void kpb_micselect_copy16(struct comp_buffer *sink,
 {
 	struct audio_stream *istream = &source->stream;
 	struct audio_stream *ostream = &sink->stream;
-
-	buffer_stream_invalidate(source, size);
 	size_t out_samples;
-	uint16_t ch;
+	uint32_t ch;
 
 	const int16_t *in_data;
 	int16_t *out_data;
-	const uint32_t samples_per_chan = size / (sizeof(uint16_t) * micsel_channels);
+	const size_t samples_per_chan = size / (sizeof(uint16_t) * micsel_channels);
+
+	buffer_stream_invalidate(source, samples_per_chan * in_channels * sizeof(uint16_t));
 
 	for (ch = 0; ch < micsel_channels; ch++) {
 		out_samples = 0;
@@ -1132,13 +1134,13 @@ static void kpb_micselect_copy32(struct comp_buffer *sink,
 {
 	struct audio_stream *istream = &source->stream;
 	struct audio_stream *ostream = &sink->stream;
-
-	buffer_stream_invalidate(source, size);
 	size_t out_samples;
-	uint16_t ch;
+	uint32_t ch;
 	const int32_t *in_data;
 	int32_t *out_data;
-	const uint32_t samples_per_chan = size / (sizeof(uint32_t) * micsel_channels);
+	const size_t samples_per_chan = size / (sizeof(uint32_t) * micsel_channels);
+
+	buffer_stream_invalidate(source, samples_per_chan * in_channels * sizeof(uint32_t));
 
 	for (ch = 0; ch < micsel_channels; ch++) {
 		out_samples = 0;
@@ -1607,7 +1609,7 @@ static void kpb_init_draining(struct comp_dev *dev, struct kpb_client *cli)
 	struct comp_data *kpb = comp_get_drvdata(dev);
 	bool is_sink_ready = (comp_buffer_get_sink_state(kpb->host_sink) == COMP_STATE_ACTIVE);
 	size_t sample_width = kpb->config.sampling_width;
-	size_t drain_req = cli->drain_req * kpb->config.channels *
+	size_t drain_req = (size_t)cli->drain_req * kpb->config.channels *
 			       (kpb->config.sampling_freq / 1000) *
 			       (KPB_SAMPLE_CONTAINER_SIZE(sample_width) / 8);
 	struct history_buffer *buff = kpb->hd.c_hb;
@@ -1616,7 +1618,7 @@ static void kpb_init_draining(struct comp_dev *dev, struct kpb_client *cli)
 	size_t local_buffered;
 	size_t drain_interval;
 	size_t host_period_size = kpb->host_period_size;
-	size_t bytes_per_ms = KPB_SAMPLES_PER_MS *
+	size_t bytes_per_ms = (size_t)KPB_SAMPLES_PER_MS *
 			      (KPB_SAMPLE_CONTAINER_SIZE(sample_width) / 8) *
 			      kpb->config.channels;
 	size_t period_bytes_limit;
@@ -1788,7 +1790,7 @@ static void adjust_drain_interval(struct comp_data *kpb, struct draining_data *d
 		/* average drained bytes per second */
 		actual_pace = (size_t)k_ms_to_cyc_ceil64(1000) / elapsed * drained;
 
-		pipeline_period = KPB_SAMPLES_PER_MS *
+		pipeline_period = (size_t)KPB_SAMPLES_PER_MS *
 			(KPB_SAMPLE_CONTAINER_SIZE(dd->sample_width) / 8) * kpb->config.channels;
 		/* desired draining pace in bytes per second */
 		optimal_pace = pipeline_period * KPB_DRAIN_NUM_OF_PPL_PERIODS_AT_ONCE * 1000;
@@ -2394,7 +2396,7 @@ static inline bool validate_host_params(struct comp_dev *dev,
 	 */
 	struct comp_data *kpb = comp_get_drvdata(dev);
 	size_t sample_width = kpb->config.sampling_width;
-	size_t bytes_per_ms = KPB_SAMPLES_PER_MS *
+	size_t bytes_per_ms = (size_t)KPB_SAMPLES_PER_MS *
 			      (KPB_SAMPLE_CONTAINER_SIZE(sample_width) / 8) *
 			      kpb->config.channels;
 	size_t pipeline_period_size = (dev->pipeline->period / 1000)