ASoC: SOF: Intel: hda-dai: fix possible stream_tag leak

The HDaudio stream allocation is done first, and in a second step the
LOSIDV parameter is programmed for the multi-link used by a codec.

This leads to a possible stream_tag leak, e.g. if a DisplayAudio link
is not used. This would happen when a non-Intel graphics card is used
and userspace unconditionally uses the Intel Display Audio PCMs without
checking if they are connected to a receiver with jack controls.

We should first check that there is a valid multi-link entry to
configure before allocating a stream_tag. This change aligns the
dma_assign and dma_cleanup phases.

Complements: b0cd60f3e9f5 ("ALSA/ASoC: hda: clarify bus_get_link() and bus_link_get() helpers")
Link: https://github.com/thesofproject/linux/issues/4151
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20230216162340.19480-1-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/sof/intel/hda-dai.c b/sound/soc/sof/intel/hda-dai.c
index 1c3d4887aa304c15d1f56a39b3ef1a4cae308b40..a642c3067ec5c83fbefb56532314064016759bf2 100644 (file)
--- a/sound/soc/sof/intel/hda-dai.c
+++ b/sound/soc/sof/intel/hda-dai.c
@@ -216,6 +216,10 @@ static int hda_link_dma_hw_params(struct snd_pcm_substream *substream,
        sdev = snd_soc_component_get_drvdata(cpu_dai->component);
        bus = sof_to_bus(sdev);
 
+       hlink = snd_hdac_ext_bus_get_hlink_by_name(bus, codec_dai->component->name);
+       if (!hlink)
+               return -EINVAL;
+
        hext_stream = snd_soc_dai_get_dma_data(cpu_dai, substream);
        if (!hext_stream) {
                hext_stream = hda_link_stream_assign(bus, substream);
@@ -225,10 +229,6 @@ static int hda_link_dma_hw_params(struct snd_pcm_substream *substream,
                snd_soc_dai_set_dma_data(cpu_dai, substream, (void *)hext_stream);
        }
 
-       hlink = snd_hdac_ext_bus_get_hlink_by_name(bus, codec_dai->component->name);
-       if (!hlink)
-               return -EINVAL;
-
        /* set the hdac_stream in the codec dai */
        snd_soc_dai_set_stream(codec_dai, hdac_stream(hext_stream), substream->stream);