If snd_hda_hdmi_codec module is denylisted and any event causes i915 enumeration to fail, is_likely_hdmi_codec() ends in null-ptr-deref.
As snd_soc_hda is an ASoC-based driver, its initialization is delayed until all the necessary components appear in the system - allowing actual sound card to enumerate. snd_hda_codec_configure() gets called by the avs-driver core during probe_codecs() but the snd_hda_codec_device_new(), necessary to complete codecs initialization, happens only when codec-component of hda sound card is being probed.
Denylisting snd_hda_codec_hdmi module causes snd_hda_codec_configure() to reach: codec_bind_generic() -> is_likely_hdmi_codec() which makes use of ->wcaps and at this point the it isn't initialized yet - again, requires completion of snd_hda_codec_device_new().
Signed-off-by: Cezary Rojewski cezary.rojewski@intel.com --- sound/pci/hda/hda_bind.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/sound/pci/hda/hda_bind.c b/sound/pci/hda/hda_bind.c index c572fb5886d5..cae9a975cbcc 100644 --- a/sound/pci/hda/hda_bind.c +++ b/sound/pci/hda/hda_bind.c @@ -248,6 +248,13 @@ static bool is_likely_hdmi_codec(struct hda_codec *codec) { hda_nid_t nid;
+ /* + * For ASoC users, if snd_hda_hdmi_codec module is denylisted and any + * event causes i915 enumeration to fail, ->wcaps remains uninitialized. + */ + if (!codec->wcaps) + return true; + for_each_hda_codec_node(nid, codec) { unsigned int wcaps = get_wcaps(codec, nid); switch (get_wcaps_type(wcaps)) {