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>

1 files changed, 7 insertions, 5 deletions

diff --git a/sound/pci/oxygen/oxygen_mixer.c b/sound/pci/oxygen/oxygen_mixer.c
index cc0cddadd589..6facac5aed90 100644
--- 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;