ASoC: topology: Fix kcontrol name string handling

Fix the topology kcontrol string handling so that string pointer
references are strdup()ed instead of being copied. This fixes issues
with kcontrol templates on the stack or ones that are freed. Remember
and free the strings too when topology is unloaded.
Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

sound/soc/soc-topology.c

@@ -523,6 +523,7 @@ static void remove_widget(struct snd_soc_component *comp,
 				kfree(se->dobj.control.dtexts[j]);
 
 			kfree(se);
+			kfree(w->kcontrol_news[i].name);
 		}
 		kfree(w->kcontrol_news);
 	} else {
@@ -540,6 +541,7 @@ static void remove_widget(struct snd_soc_component *comp,
 			 */
 			kfree((void *)kcontrol->private_value);
 			snd_ctl_remove(card, kcontrol);
+			kfree(w->kcontrol_news[i].name);
 		}
 		kfree(w->kcontrol_news);
 	}
@@ -1233,7 +1235,9 @@ static struct snd_kcontrol_new *soc_tplg_dapm_widget_dmixer_create(
 		dev_dbg(tplg->dev, " adding DAPM widget mixer control %s at %d\n",
 			mc->hdr.name, i);
 
-		kc[i].name = mc->hdr.name;
+		kc[i].name = kstrdup(mc->hdr.name, GFP_KERNEL);
+		if (kc[i].name == NULL)
+			goto err_str;
 		kc[i].private_value = (long)sm;
 		kc[i].iface = SNDRV_CTL_ELEM_IFACE_MIXER;
 		kc[i].access = mc->hdr.access;
@@ -1278,8 +1282,10 @@ static struct snd_kcontrol_new *soc_tplg_dapm_widget_dmixer_create(
 err_str:
 	kfree(sm);
 err:
-	for (--i; i >= 0; i--)
+	for (--i; i >= 0; i--) {
 		kfree((void *)kc[i].private_value);
+		kfree(kc[i].name);
+	}
 	kfree(kc);
 	return NULL;
 }
@@ -1310,7 +1316,9 @@ static struct snd_kcontrol_new *soc_tplg_dapm_widget_denum_create(
 		dev_dbg(tplg->dev, " adding DAPM widget enum control %s\n",
 			ec->hdr.name);
 
-		kc[i].name = ec->hdr.name;
+		kc[i].name = kstrdup(ec->hdr.name, GFP_KERNEL);
+		if (kc[i].name == NULL)
+			goto err_se;
 		kc[i].private_value = (long)se;
 		kc[i].iface = SNDRV_CTL_ELEM_IFACE_MIXER;
 		kc[i].access = ec->hdr.access;
@@ -1386,6 +1394,7 @@ static struct snd_kcontrol_new *soc_tplg_dapm_widget_denum_create(
 			kfree(se->dobj.control.dtexts[j]);
 
 		kfree(se);
+		kfree(kc[i].name);
 	}
 err:
 	kfree(kc);
@@ -1424,7 +1433,9 @@ static struct snd_kcontrol_new *soc_tplg_dapm_widget_dbytes_create(
 			"ASoC: adding bytes kcontrol %s with access 0x%x\n",
 			be->hdr.name, be->hdr.access);
 
-		kc[i].name = be->hdr.name;
+		kc[i].name = kstrdup(be->hdr.name, GFP_KERNEL);
+		if (kc[i].name == NULL)
+			goto err;
 		kc[i].private_value = (long)sbe;
 		kc[i].iface = SNDRV_CTL_ELEM_IFACE_MIXER;
 		kc[i].access = be->hdr.access;
@@ -1454,8 +1465,10 @@ static struct snd_kcontrol_new *soc_tplg_dapm_widget_dbytes_create(
 	return kc;
 
 err:
-	for (--i; i >= 0; i--)
+	for (--i; i >= 0; i--) {
 		kfree((void *)kc[i].private_value);
+		kfree(kc[i].name);
+	}
 
 	kfree(kc);
 	return NULL;