sound: oxygen: fix NULL pointer dereference when loading snd-oxygen

Check that model->control_filter is set before trying to call it.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/pci/oxygen/oxygen_mixer.c b/sound/pci/oxygen/oxygen_mixer.c
index cc0cdda..6facac5 100644 (file)
--- a/sound/pci/oxygen/oxygen_mixer.c
+++ b/sound/pci/oxygen/oxygen_mixer.c
@@ -936,11 +936,13 @@ static int add_controls(struct oxygen *chip,
 
        for (i = 0; i < count; ++i) {
                template = controls[i];
-               err = chip->model->control_filter(&template);
-               if (err < 0)
-                       return err;
-               if (err == 1)
-                       continue;
+               if (chip->model->control_filter) {
+                       err = chip->model->control_filter(&template);
+                       if (err < 0)
+                               return err;
+                       if (err == 1)
+                               continue;
+               }
                if (!strcmp(template.name, "Master Playback Volume") &&
                    chip->model->dac_tlv) {
                        template.tlv.p = chip->model->dac_tlv;