ASoC: dapm: Lock during userspace access
The DAPM lock must be held when accessing the DAPM graph status through
sysfs or debugfs, otherwise concurrent changes to the graph can result in
undefined behaviour.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index a47a8ce..1779430 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -1952,6 +1952,7 @@
size_t count, loff_t *ppos)
{
struct snd_soc_dapm_widget *w = file->private_data;
+ struct snd_soc_card *card = w->dapm->card;
char *buf;
int in, out;
ssize_t ret;
@@ -1961,6 +1962,8 @@
if (!buf)
return -ENOMEM;
+ mutex_lock(&card->dapm_mutex);
+
/* Supply widgets are not handled by is_connected_{input,output}_ep() */
if (w->is_supply) {
in = 0;
@@ -2007,6 +2010,8 @@
p->sink->name);
}
+ mutex_unlock(&card->dapm_mutex);
+
ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
kfree(buf);
@@ -2281,11 +2286,15 @@
struct snd_soc_pcm_runtime *rtd = dev_get_drvdata(dev);
int i, count = 0;
+ mutex_lock(&rtd->card->dapm_mutex);
+
for (i = 0; i < rtd->num_codecs; i++) {
struct snd_soc_codec *codec = rtd->codec_dais[i]->codec;
count += dapm_widget_show_codec(codec, buf + count);
}
+ mutex_unlock(&rtd->card->dapm_mutex);
+
return count;
}