[PATCH AUTOSEL 5.1 201/219] ASoC: audio-graph-card: fix use-after-free in graph_for_each_link

Sasha Levin
2019-07-15T14:16:16Z

From: Wen Yang <wen.yang99@zte.com.cn>

[ Upstream commit 1bcc1fd64e4dd903f4d868a9e053986e3b102713 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/soc/generic/audio-graph-card.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/sound/soc/generic/audio-graph-card.c b/sound/soc/generic/audio-graph-card.c
index 69bc4848d787..f730830fb36c 100644
--- a/sound/soc/generic/audio-graph-card.c
+++ b/sound/soc/generic/audio-graph-card.c
@@ -460,9 +460,6 @@ static int graph_for_each_link(struct graph_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_get_conversion(dev, codec_ep, &adata);
@@ -482,6 +479,9 @@ static int graph_for_each_link(struct graph_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;

--
2.20.1