[PATCH 3/4] ASoC: audio-graph-card: fix use-after-free in graph_dai_link_of_dpcm()

[Wen Yang]

After calling of_node_put() on the ports, port, and node variables,
they are still being used, which may result in use-after-free.
Fix this issue by calling of_node_put() after the last usage.

Fixes: dd98fbc558a0 ("ASoC: audio-graph-card: cleanup DAI link loop method - 
step1")
Signed-off-by: Wen Yang <wen.yan...@zte.com.cn>
Cc: Liam Girdwood <lgirdw...@gmail.com>
Cc: Mark Brown <broo...@kernel.org>
Cc: Jaroslav Kysela <pe...@perex.cz>
Cc: Takashi Iwai <ti...@suse.com>
Cc: Kuninori Morimoto <kuninori.morimoto...@renesas.com>
Cc: alsa-de...@alsa-project.org
Cc: linux-kernel@vger.kernel.org
---
 sound/soc/generic/audio-graph-card.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/sound/soc/generic/audio-graph-card.c 
b/sound/soc/generic/audio-graph-card.c
index 30a4e83..31fc83d 100644
--- a/sound/soc/generic/audio-graph-card.c
+++ b/sound/soc/generic/audio-graph-card.c
@@ -208,10 +208,6 @@ static int graph_dai_link_of_dpcm(struct asoc_simple_priv 
*priv,
 
        dev_dbg(dev, "link_of DPCM (%pOF)\n", ep);
 
-       of_node_put(ports);
-       of_node_put(port);
-       of_node_put(node);
-
        if (li->cpu) {
                int is_single_links = 0;
 
@@ -229,17 +225,17 @@ static int graph_dai_link_of_dpcm(struct asoc_simple_priv 
*priv,
 
                ret = asoc_simple_parse_cpu(ep, dai_link, &is_single_links);
                if (ret)
-                       return ret;
+                       goto out_put_node;
 
                ret = asoc_simple_parse_clk_cpu(dev, ep, dai_link, dai);
                if (ret < 0)
-                       return ret;
+                       goto out_put_node;
 
                ret = asoc_simple_set_dailink_name(dev, dai_link,
                                                   "fe.%s",
                                                   cpus->dai_name);
                if (ret < 0)
-                       return ret;
+                       goto out_put_node;
 
                /* card->num_links includes Codec */
                asoc_simple_canonicalize_cpu(dai_link, is_single_links);
@@ -263,17 +259,17 @@ static int graph_dai_link_of_dpcm(struct asoc_simple_priv 
*priv,
 
                ret = asoc_simple_parse_codec(ep, dai_link);
                if (ret < 0)
-                       return ret;
+                       goto out_put_node;
 
                ret = asoc_simple_parse_clk_codec(dev, ep, dai_link, dai);
                if (ret < 0)
-                       return ret;
+                       goto out_put_node;
 
                ret = asoc_simple_set_dailink_name(dev, dai_link,
                                                   "be.%s",
                                                   codecs->dai_name);
                if (ret < 0)
-                       return ret;
+                       goto out_put_node;
 
                /* check "prefix" from top node */
                snd_soc_of_parse_node_prefix(top, cconf, codecs->of_node,
@@ -293,19 +289,23 @@ static int graph_dai_link_of_dpcm(struct asoc_simple_priv 
*priv,
 
        ret = asoc_simple_parse_tdm(ep, dai);
        if (ret)
-               return ret;
+               goto out_put_node;
 
        ret = asoc_simple_parse_daifmt(dev, cpu_ep, codec_ep,
                                       NULL, &dai_link->dai_fmt);
        if (ret < 0)
-               return ret;
+               goto out_put_node;
 
        dai_link->dpcm_playback         = 1;
        dai_link->dpcm_capture          = 1;
        dai_link->ops                   = &graph_ops;
        dai_link->init                  = asoc_simple_dai_init;
 
-       return 0;
+out_put_node:
+       of_node_put(ports);
+       of_node_put(port);
+       of_node_put(node);
+       return ret;
 }
 
 static int graph_dai_link_of(struct asoc_simple_priv *priv,
-- 
2.9.5