ASoC: topology: Fix route memory corruption

It was reported that recent fix for memory corruption during topology
load, causes corruption in other cases. Instead of being overeager with
checking topology, assume that it is properly formatted and just
duplicate strings.
Reported-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Closes: https://lore.kernel.org/linux-sound/171812236450.201359.3019210915105428447.b4-ty@kernel.org/T/#m8c4bd5abf453960fde6f826c4b7f84881da63e9dSuggested-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Link: https://lore.kernel.org/r/20240613090126.841189-1-amadeuszx.slawinski@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-topology.c

@@ -1052,21 +1052,15 @@ static int soc_tplg_dapm_graph_elems_load(struct soc_tplg *tplg,
 			break;
 		}
 
-		route->source = devm_kmemdup(tplg->dev, elem->source,
-					     min(strlen(elem->source), maxlen),
-					     GFP_KERNEL);
-		route->sink = devm_kmemdup(tplg->dev, elem->sink,
-					   min(strlen(elem->sink), maxlen),
-					   GFP_KERNEL);
+		route->source = devm_kstrdup(tplg->dev, elem->source, GFP_KERNEL);
+		route->sink = devm_kstrdup(tplg->dev, elem->sink, GFP_KERNEL);
 		if (!route->source || !route->sink) {
 			ret = -ENOMEM;
 			break;
 		}
 
 		if (strnlen(elem->control, maxlen) != 0) {
-			route->control = devm_kmemdup(tplg->dev, elem->control,
-						      min(strlen(elem->control), maxlen),
-						      GFP_KERNEL);
+			route->control = devm_kstrdup(tplg->dev, elem->control, GFP_KERNEL);
 			if (!route->control) {
 				ret = -ENOMEM;
 				break;