[alsa-devel] [PATCH] ASoC: topology: Check widget kcontrols before deref.

[Liam Girdwood]

Validate the topology input before we dereference the pointer.

Signed-off-by: Liam Girdwood <liam.r.girdwood at linux.intel.com>
---
 sound/soc/soc-topology.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/sound/soc/soc-topology.c b/sound/soc/soc-topology.c
index 4616286869a8..78197e82fc4f 100644
--- a/sound/soc/soc-topology.c
+++ b/sound/soc/soc-topology.c
@@ -508,6 +508,9 @@ static void remove_widget(struct snd_soc_component *comp,
 	if (dobj->ops && dobj->ops->widget_unload)
 		dobj->ops->widget_unload(comp, dobj);
 
+	if (!w->kcontrols)
+		goto free_news;
+
 	/*
 	 * Dynamic Widgets either have 1..N enum kcontrols or mixers.
 	 * The enum may either have an array of values or strings.
@@ -528,7 +531,6 @@ static void remove_widget(struct snd_soc_component *comp,
 
 			kfree(se);
 		}
-		kfree(w->kcontrol_news);
 	} else {
 		/* volume mixer or bytes controls */
 		for (i = 0; i < w->num_kcontrols; i++) {
@@ -545,8 +547,11 @@ static void remove_widget(struct snd_soc_component *comp,
 			kfree((void *)kcontrol->private_value);
 			snd_ctl_remove(card, kcontrol);
 		}
-		kfree(w->kcontrol_news);
 	}
+
+free_news:
+	kfree(w->kcontrol_news);
+
 	/* widget w is freed by soc-dapm.c */
 }
 
-- 
2.14.1