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>

diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index c687e14733d7fa71e2fb36f6acfa56cac9c15cce..20d920743e7c4ea78cd69aaecf5b4158bb315559 100644 (file)
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -280,6 +280,8 @@ static int alc_mux_select(struct hda_codec *codec, unsigned int adc_idx,
        imux = &spec->input_mux[mux_idx];
        if (!imux->num_items && mux_idx > 0)
                imux = &spec->input_mux[0];
+       if (!imux->num_items)
+               return 0;
 
        if (idx >= imux->num_items)
                idx = imux->num_items - 1;