Re: [alsa-devel] [PATCH] sound: hdmi: avoid dereferencing uninitialized 'jack' pointer

On Tuesday 16 February 2016 17:59:04 Arnd Bergmann wrote:

--- a/sound/pci/hda/hda_jack.c +++ b/sound/pci/hda/hda_jack.c @@ -403,8 +403,10 @@ int snd_hda_jack_add_kctl(struct hda_codec *codec, hda_nid_t nid,

    jack->phantom_jack = !!phantom_jack;
    jack->type = type;

•   jack->jack->private_data = jack;
  

•   jack->jack->private_free = hda_free_jack_priv;
  

•   if (IS_ENABLED(CONFIG_SND_JACK)) {
  

•           jack->jack->private_data = jack;
  

•           jack->jack->private_free = hda_free_jack_priv;
  

•   }
    state = snd_hda_jack_detect(codec, nid);
    snd_jack_report(jack->jack, state ? jack->type : 0);
  
  

Or another idea: if we pass private_{data,free} into snd_jack_new() as arguments, the snd_jack structure can become private to sound/core/jack.c, so we can be sure to never hit this bug again.

Arnd