From:   Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
To:     stable@vger.kernel.org
Cc:     sashal@kernel.org, broonie@kernel.org, alsa-devel@alsa-project.org,
        pierre-louis.bossart@linux.intel.com,
        ranjani.sridharan@linux.intel.com, gregkh@linuxfoundation.org
Subject: [PATCH BACKPORT 5.4] ASoC: SOF: Intel: hda-dai: fix possible stream_tag leak
Date:   Mon, 20 Feb 2023 13:17:21 +0200
Message-Id: <20230220111721.32502-1-peter.ujfalusi@linux.intel.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

[ Upstream commit 1f810d2b6b2fbdc5279644d8b2c140b1f7c9d43d ]

There were just too many code changes since 5.4 stable to prevent clean
picking the fix from mainline.

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.

Cc: stable@vger.kernel.org # 5.4.x
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>
---
 sound/soc/sof/intel/hda-dai.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/sound/soc/sof/intel/hda-dai.c b/sound/soc/sof/intel/hda-dai.c
index b3cdd10c83ae..c30e450fa970 100644
--- a/sound/soc/sof/intel/hda-dai.c
+++ b/sound/soc/sof/intel/hda-dai.c
@@ -211,6 +211,10 @@ static int hda_link_hw_params(struct snd_pcm_substream *substream,
 	int stream_tag;
 	int ret;
 
+	link = snd_hdac_ext_bus_get_link(bus, codec_dai->component->name);
+	if (!link)
+		return -EINVAL;
+
 	/* get stored dma data if resuming from system suspend */
 	link_dev = snd_soc_dai_get_dma_data(dai, substream);
 	if (!link_dev) {
@@ -231,10 +235,6 @@ static int hda_link_hw_params(struct snd_pcm_substream *substream,
 	if (ret < 0)
 		return ret;
 
-	link = snd_hdac_ext_bus_get_link(bus, codec_dai->component->name);
-	if (!link)
-		return -EINVAL;
-
 	/* set the stream tag in the codec dai dma params */
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 		snd_soc_dai_set_tdm_slot(codec_dai, stream_tag, 0, 0, 0);
-- 
2.39.2