ASoC: wm_asdp: Validate sanity of algorithm count

If we run into I/O problems the algorithm count may be crazy, validate it
before we proceed and dump the read data for diagnostic purposes.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/wm_adsp.c

@@ -377,10 +377,10 @@ static int wm_adsp_setup_algs(struct wm_adsp *dsp)
 	struct wmfw_adsp2_id_hdr adsp2_id;
 	struct wmfw_adsp1_alg_hdr *adsp1_alg;
 	struct wmfw_adsp2_alg_hdr *adsp2_alg;
-	void *alg;
+	void *alg, *buf;
 	const struct wm_adsp_region *mem;
 	unsigned int pos, term;
-	size_t algs;
+	size_t algs, buf_size;
 	__be32 val;
 	int i, ret;
 
@@ -411,6 +411,9 @@ static int wm_adsp_setup_algs(struct wm_adsp *dsp)
 			return ret;
 		}
 
+		buf = &adsp1_id;
+		buf_size = sizeof(adsp1_id);
+
 		algs = be32_to_cpu(adsp1_id.algs);
 		adsp_info(dsp, "Firmware: %x v%d.%d.%d, %zu algorithms\n",
 			  be32_to_cpu(adsp1_id.fw.id),
@@ -432,6 +435,9 @@ static int wm_adsp_setup_algs(struct wm_adsp *dsp)
 			return ret;
 		}
 
+		buf = &adsp2_id;
+		buf_size = sizeof(adsp2_id);
+
 		algs = be32_to_cpu(adsp2_id.algs);
 		adsp_info(dsp, "Firmware: %x v%d.%d.%d, %zu algorithms\n",
 			  be32_to_cpu(adsp2_id.fw.id),
@@ -454,6 +460,13 @@ static int wm_adsp_setup_algs(struct wm_adsp *dsp)
 		return -EINVAL;
 	}
 
+	if (algs > 1024) {
+		adsp_err(dsp, "Algorithm count %zx excessive\n", algs);
+		print_hex_dump_bytes(dev_name(dsp->dev), DUMP_PREFIX_OFFSET,
+				     buf, buf_size);
+		return -EINVAL;
+	}
+
 	/* Read the terminator first to validate the length */
 	ret = regmap_raw_read(regmap, mem->base + term, &val, sizeof(val));
 	if (ret != 0) {