linux-kernel - [PATCH] ASoC: ux500: mop500: Fix some refcounted resources issues

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Date:   Tue, 12 May 2020 12:07:05 +0200
From:   Christophe JAILLET <christophe.jaillet@...adoo.fr>
To:     lgirdwood@...il.com, broonie@...nel.org, perex@...ex.cz,
        tiwai@...e.com, linus.walleij@...aro.org, lee.jones@...aro.org
Cc:     alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
        kernel-janitors@...r.kernel.org,
        Christophe JAILLET <christophe.jaillet@...adoo.fr>
Subject: [PATCH] ASoC: ux500: mop500: Fix some refcounted resources issues

There are 2 issues here:
   - if one of the 'of_parse_phandle' fails, calling 'mop500_of_node_put()'
     is a no-op because the 'mop500_dai_links' structure has not been
     initialized yet, so the referenced are not decremented
   - The reference stored in 'mop500_dai_links[i].codecs' is refcounted
     only once in the probe and must be decremented only once.

Fixes: 39013bd60e79 ("ASoC: Ux500: Dispose of device nodes correctly")
Signed-off-by: Christophe JAILLET <christophe.jaillet@...adoo.fr>
---
 sound/soc/ux500/mop500.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/sound/soc/ux500/mop500.c b/sound/soc/ux500/mop500.c
index 2873e8e6f02b..cdae1190b930 100644
--- a/sound/soc/ux500/mop500.c
+++ b/sound/soc/ux500/mop500.c
@@ -63,10 +63,11 @@ static void mop500_of_node_put(void)
 {
 	int i;
 
-	for (i = 0; i < 2; i++) {
+	for (i = 0; i < 2; i++)
 		of_node_put(mop500_dai_links[i].cpus->of_node);
-		of_node_put(mop500_dai_links[i].codecs->of_node);
-	}
+
+	/* Both links use the same codec, which is refcounted only once */
+	of_node_put(mop500_dai_links[0].codecs->of_node);
 }
 
 static int mop500_of_probe(struct platform_device *pdev,
@@ -81,7 +82,9 @@ static int mop500_of_probe(struct platform_device *pdev,
 
 	if (!(msp_np[0] && msp_np[1] && codec_np)) {
 		dev_err(&pdev->dev, "Phandle missing or invalid\n");
-		mop500_of_node_put();
+		for (i = 0; i < 2; i++)
+			of_node_put(msp_np[i]);
+		of_node_put(codec_np);
 		return -EINVAL;
 	}
 
-- 
2.25.1