path: root/sound
diff options
authorLars-Peter Clausen <>2013-08-01 18:30:38 +0200
committerGreg Kroah-Hartman <>2013-08-20 08:43:03 -0700
commit4bd3f15b77578866fda9b0da4ef027f06ed3b746 (patch)
tree3181d776657e190ba88821e669e08db1f64d05f3 /sound
parent20fd3d46726e60f936e8901745a7d00bae32958f (diff)
ASoC: dapm: Fix empty list check in dapm_new_mux()
commit fe581391147cb3d738d961d0f1233d91a9e1113c upstream. list_first_entry() will always return a valid pointer, even if the list is empty. So the check whether path is NULL will always be false. So we end up calling dapm_create_or_share_mixmux_kcontrol() with a path struct that points right in the middle of the widget struct and by trying to modify the path the widgets memory will become corrupted. Fix this by using list_emtpy() to check if the widget doesn't have any paths. Signed-off-by: Lars-Peter Clausen <> Tested-by: Stephen Warren <> Signed-off-by: Mark Brown <> Signed-off-by: Greg Kroah-Hartman <>
Diffstat (limited to 'sound')
1 files changed, 4 insertions, 3 deletions
diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index c7051c457b75..360638362e98 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -682,13 +682,14 @@ static int dapm_new_mux(struct snd_soc_dapm_widget *w)
return -EINVAL;
- path = list_first_entry(&w->sources, struct snd_soc_dapm_path,
- list_sink);
- if (!path) {
+ if (list_empty(&w->sources)) {
dev_err(dapm->dev, "ASoC: mux %s has no paths\n", w->name);
return -EINVAL;
+ path = list_first_entry(&w->sources, struct snd_soc_dapm_path,
+ list_sink);
ret = dapm_create_or_share_mixmux_kcontrol(w, 0, path);
if (ret < 0)
return ret;