tools/probe: clamp out-of-range sample-rate index to a valid default

The 4-bit sample-rate field can select an index past the end of the
sample_rate[] table, which has fewer than 16 entries, reading out of bounds.
Clamp an out-of-range index to a valid default rate (48000 Hz) so the read stays
in bounds and the generated WAV header keeps a usable sample rate.

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

Author: lrgirdwo

tools/probes/probes_demux.c

@@ -59,6 +59,11 @@ static uint32_t sample_rate[] = {
 	48000, 64000, 88200, 96000, 128000, 176400, 192000
 };
 
+/* fallback index (48000 Hz) used when the probe's 4-bit rate field is out of
+ * range, so the generated WAV header keeps a valid sample rate
+ */
+#define PROBE_DEFAULT_RATE_IDX 8
+
 int get_buffer_file(struct wave_files *files, uint32_t buffer_id)
 {
 	int i;
@@ -125,7 +130,16 @@ int init_wave(struct dma_frame_parser *p, uint32_t buffer_id, uint32_t format)
 	p->files[i].header.fmt.subchunk_size = 16;
 	p->files[i].header.fmt.audio_format = 1;
 	p->files[i].header.fmt.num_channels = ((format & PROBE_MASK_NB_CHANNELS) >> PROBE_SHIFT_NB_CHANNELS) + 1;
-	p->files[i].header.fmt.sample_rate = sample_rate[(format & PROBE_MASK_SAMPLE_RATE) >> PROBE_SHIFT_SAMPLE_RATE];
+	/* the sample-rate field is 4 bits (0-15) but the table has fewer
+	 * entries; clamp an out-of-range index to a valid default so the read
+	 * stays in bounds and the WAV header keeps a usable rate
+	 */
+	uint32_t rate_idx = (format & PROBE_MASK_SAMPLE_RATE) >> PROBE_SHIFT_SAMPLE_RATE;
+
+	if (rate_idx >= sizeof(sample_rate) / sizeof(sample_rate[0]))
+		rate_idx = PROBE_DEFAULT_RATE_IDX;
+
+	p->files[i].header.fmt.sample_rate = sample_rate[rate_idx];
 	p->files[i].header.fmt.bits_per_sample = (((format & PROBE_MASK_CONTAINER_SIZE) >> PROBE_SHIFT_CONTAINER_SIZE) + 1) * 8;
 	p->files[i].header.fmt.byte_rate = p->files[i].header.fmt.sample_rate *
 					p->files[i].header.fmt.num_channels *