From 267e2c6fd7ca3d4076d20f9d52d49dc91addfe9d Mon Sep 17 00:00:00 2001
From: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Date: Tue, 27 Mar 2018 12:04:04 +0100
Subject: [PATCH] ASoC: topology: Fix kcontrol name string handling
Git-commit: 267e2c6fd7ca3d4076d20f9d52d49dc91addfe9d
Patch-mainline: v4.17-rc1
References: bsc#1051510

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
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 sound/soc/soc-topology.c |   23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

--- a/sound/soc/soc-topology.c
+++ b/sound/soc/soc-topology.c
@@ -504,6 +504,7 @@ static void remove_widget(struct snd_soc
 				kfree(se->dobj.control.dtexts[j]);
 
 			kfree(se);
+			kfree(w->kcontrol_news[i].name);
 		}
 		kfree(w->kcontrol_news);
 	} else {
@@ -521,6 +522,7 @@ static void remove_widget(struct snd_soc
 			 */
 			kfree((void *)kcontrol->private_value);
 			snd_ctl_remove(card, kcontrol);
+			kfree(w->kcontrol_news[i].name);
 		}
 		kfree(w->kcontrol_news);
 	}
@@ -1213,7 +1215,9 @@ static struct snd_kcontrol_new *soc_tplg
 		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;
@@ -1258,8 +1262,10 @@ static struct snd_kcontrol_new *soc_tplg
 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;
 }
@@ -1290,7 +1296,9 @@ static struct snd_kcontrol_new *soc_tplg
 		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;
@@ -1366,6 +1374,7 @@ err_se:
 			kfree(se->dobj.control.dtexts[j]);
 
 		kfree(se);
+		kfree(kc[i].name);
 	}
 err:
 	kfree(kc);
@@ -1404,7 +1413,9 @@ static struct snd_kcontrol_new *soc_tplg
 			"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;
@@ -1434,8 +1445,10 @@ static struct snd_kcontrol_new *soc_tplg
 	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;