From f53c4c20d6d38bcefd89bfcab135486cbb797884 Mon Sep 17 00:00:00 2001
From: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Date: Tue, 27 Mar 2018 14:30:44 +0100
Subject: [PATCH] ASoC: topology: Check widget kcontrols before deref
Git-commit: f53c4c20d6d38bcefd89bfcab135486cbb797884
Patch-mainline: v4.17-rc3
References: bsc#1051510

Validate the topology input before we dereference the pointer.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 sound/soc/soc-topology.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/sound/soc/soc-topology.c
+++ b/sound/soc/soc-topology.c
@@ -494,7 +494,7 @@ static void remove_widget(struct snd_soc
 	 */
 	if (dobj->widget.kcontrol_type == SND_SOC_TPLG_TYPE_ENUM) {
 		/* enumerated widget mixer */
-		for (i = 0; i < w->num_kcontrols; i++) {
+		for (i = 0; w->kcontrols != NULL && i < w->num_kcontrols; i++) {
 			struct snd_kcontrol *kcontrol = w->kcontrols[i];
 			struct soc_enum *se =
 				(struct soc_enum *)kcontrol->private_value;
@@ -511,7 +511,7 @@ static void remove_widget(struct snd_soc
 		}
 	} else {
 		/* volume mixer or bytes controls */
-		for (i = 0; i < w->num_kcontrols; i++) {
+		for (i = 0; w->kcontrols != NULL && i < w->num_kcontrols; i++) {
 			struct snd_kcontrol *kcontrol = w->kcontrols[i];
 
 			if (dobj->widget.kcontrol_type