ASoC: audio-graph-card: fix use-after-free in graph_for_each_link

After calling of_node_put() on the codec_ep and codec_port variables,
they are still being used, which may result in use-after-free.
We fix this issue by calling of_node_put() after the last usage.

Fixes: fce9b90c1ab7 ("ASoC: audio-graph-card: cleanup DAI link loop method - step2")
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: alsa-devel@alsa-project.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/1562229530-8121-1-git-send-email-wen.yang99@zte.com.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/generic/audio-graph-card.c b/sound/soc/generic/audio-graph-card.c
index ec7e673ba475f8ff4de5d58cf77d05ddcc9aedad..70ed28d97d49776f7f6993f9af5b809ded79ae11 100644 (file)
--- a/sound/soc/generic/audio-graph-card.c
+++ b/sound/soc/generic/audio-graph-card.c
@@ -435,9 +435,6 @@ static int graph_for_each_link(struct asoc_simple_priv *priv,
                        codec_ep = of_graph_get_remote_endpoint(cpu_ep);
                        codec_port = of_get_parent(codec_ep);
 
-                       of_node_put(codec_ep);
-                       of_node_put(codec_port);
-
                        /* get convert-xxx property */
                        memset(&adata, 0, sizeof(adata));
                        graph_parse_convert(dev, codec_ep, &adata);
@@ -457,6 +454,9 @@ static int graph_for_each_link(struct asoc_simple_priv *priv,
                        else
                                ret = func_noml(priv, cpu_ep, codec_ep, li);
 
+                       of_node_put(codec_ep);
+                       of_node_put(codec_port);
+
                        if (ret < 0)
                                return ret;