ALSA: hda/realtek - Fix Oops in alc_mux_select()

commit cce4aa378a049f4275416ee6302dd24f37b289df upstream.

When no imux is available (e.g. a single capture source),
alc_auto_init_input_src() may trigger an Oops due to the access to -1.
Add a proper zero-check to avoid it.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index e7dc0340da6..eb0a141966a 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -509,6 +509,8 @@ static int alc_mux_enum_put(struct snd_kcontrol *kcontrol,
         imux = &spec->input_mux[mux_idx];
         if (!imux->num_items && mux_idx > 0)
                 imux = &spec->input_mux[0];
+        if (!imux->num_items)
+                return 0;
 
         type = get_wcaps_type(get_wcaps(codec, nid));
         if (type == AC_WID_AUD_MIX) {