ASoC: core: Fix access to uninitialized list heads

The error path of soc_new_pcm_runtime() invokes soc_free_pcm_runtime()
that may cause a few problems.  First off, it calls list_del() for
rtd->list that may not be initialized.  Similarly,
snd_soc_pcm_component_free() traverses over the component list that
may not be initialized, either.  Such access to the uninitialized list
head would lead to either a BUG_ON() or a memory corruption.

This patch fixes the access to uninitialized list heads by
initializing the list heads properly at the beginning before those
error paths.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20191204151454.21643-1-tiwai@suse.de
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 6050c4c..8ef0efe 100644 (file)
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -479,6 +479,12 @@ static struct snd_soc_pcm_runtime *soc_new_pcm_runtime(
                goto free_rtd;
 
        rtd->dev = dev;
+       INIT_LIST_HEAD(&rtd->list);
+       INIT_LIST_HEAD(&rtd->component_list);
+       INIT_LIST_HEAD(&rtd->dpcm[SNDRV_PCM_STREAM_PLAYBACK].be_clients);
+       INIT_LIST_HEAD(&rtd->dpcm[SNDRV_PCM_STREAM_CAPTURE].be_clients);
+       INIT_LIST_HEAD(&rtd->dpcm[SNDRV_PCM_STREAM_PLAYBACK].fe_clients);
+       INIT_LIST_HEAD(&rtd->dpcm[SNDRV_PCM_STREAM_CAPTURE].fe_clients);
        dev_set_drvdata(dev, rtd);
        INIT_DELAYED_WORK(&rtd->delayed_work, close_delayed_work);
 
@@ -494,12 +500,6 @@ static struct snd_soc_pcm_runtime *soc_new_pcm_runtime(
        /*
         * rtd remaining settings
         */
-       INIT_LIST_HEAD(&rtd->component_list);
-       INIT_LIST_HEAD(&rtd->dpcm[SNDRV_PCM_STREAM_PLAYBACK].be_clients);
-       INIT_LIST_HEAD(&rtd->dpcm[SNDRV_PCM_STREAM_CAPTURE].be_clients);
-       INIT_LIST_HEAD(&rtd->dpcm[SNDRV_PCM_STREAM_PLAYBACK].fe_clients);
-       INIT_LIST_HEAD(&rtd->dpcm[SNDRV_PCM_STREAM_CAPTURE].fe_clients);
-
        rtd->card = card;
        rtd->dai_link = dai_link;
        if (!rtd->dai_link->ops)