[PATCH] ASoC: davinci-evm: Fix reference leak in davinci_evm_probe

[Kery Qi <qikeyu2017@gmail.com>]

The davinci_evm_probe() function calls of_parse_phandle() to acquire
device nodes for "ti,audio-codec" and "ti,mcasp-controller". These
functions return device nodes with incremented reference counts.

However, in several error paths (e.g., when the second of_parse_phandle(),
snd_soc_of_parse_card_name(), or devm_snd_soc_register_card() fails),
the function returns directly without releasing the acquired nodes,
leading to reference leaks.

This patch adds an error handling path 'err_put' to properly release
the device nodes using of_node_put() and clean up the pointers when
an error occurs.

Signed-off-by: Kery Qi <qikeyu2017@gmail.com>
---
 sound/soc/ti/davinci-evm.c | 39 ++++++++++++++++++++++++++++++--------
 1 file changed, 31 insertions(+), 8 deletions(-)

diff --git a/sound/soc/ti/davinci-evm.c b/sound/soc/ti/davinci-evm.c
index 3848766d96c3..ad514c2e5a25 100644
--- a/sound/soc/ti/davinci-evm.c
+++ b/sound/soc/ti/davinci-evm.c
@@ -194,27 +194,32 @@ static int davinci_evm_probe(struct platform_device *pdev)
 		return -EINVAL;
 
 	dai->cpus->of_node = of_parse_phandle(np, "ti,mcasp-controller", 0);
-	if (!dai->cpus->of_node)
-		return -EINVAL;
+	if (!dai->cpus->of_node) {
+		ret = -EINVAL;
+		goto err_put;
+	}
 
 	dai->platforms->of_node = dai->cpus->of_node;
 
 	evm_soc_card.dev = &pdev->dev;
 	ret = snd_soc_of_parse_card_name(&evm_soc_card, "ti,model");
 	if (ret)
-		return ret;
+		goto err_put;
 
 	mclk = devm_clk_get(&pdev->dev, "mclk");
 	if (PTR_ERR(mclk) == -EPROBE_DEFER) {
-		return -EPROBE_DEFER;
+		ret = -EPROBE_DEFER;
+		goto err_put;
 	} else if (IS_ERR(mclk)) {
 		dev_dbg(&pdev->dev, "mclk not found.\n");
 		mclk = NULL;
 	}
 
 	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
-	if (!drvdata)
-		return -ENOMEM;
+	if (!drvdata) {
+		ret = -ENOMEM;
+		goto err_put;
+	}
 
 	drvdata->mclk = mclk;
 
@@ -224,7 +229,8 @@ static int davinci_evm_probe(struct platform_device *pdev)
 		if (!drvdata->mclk) {
 			dev_err(&pdev->dev,
 				"No clock or clock rate defined.\n");
-			return -EINVAL;
+			ret = -EINVAL;
+			goto err_put;
 		}
 		drvdata->sysclk = clk_get_rate(drvdata->mclk);
 	} else if (drvdata->mclk) {
@@ -240,8 +246,25 @@ static int davinci_evm_probe(struct platform_device *pdev)
 	snd_soc_card_set_drvdata(&evm_soc_card, drvdata);
 	ret = devm_snd_soc_register_card(&pdev->dev, &evm_soc_card);
 
-	if (ret)
+	if (ret) {
 		dev_err(&pdev->dev, "snd_soc_register_card failed (%d)\n", ret);
+		goto err_put;
+	}
+
+	return ret;
+
+err_put:
+	dai->platforms->of_node = NULL;
+
+	if (dai->cpus->of_node) {
+		of_node_put(dai->cpus->of_node);
+		dai->cpus->of_node = NULL;
+	}
+
+	if (dai->codecs->of_node) {
+		of_node_put(dai->codecs->of_node);
+		dai->codecs->of_node = NULL;
+	}
 
 	return ret;
 }
-- 
2.34.1