From:   Ameer Hamza <amhamza.mgc@gmail.com>
To:     lgirdwood@gmail.com, broonie@kernel.org, perex@perex.cz,
        tiwai@suse.com, kuninori.morimoto.gx@renesas.com,
        alsa-devel@alsa-project.org
Cc:     linux-kernel@vger.kernel.org, amhamza.mgc@gmail.com
Subject: [PATCH v2] ASoC: test-component: fix null pointer dereference.
Date:   Tue,  7 Dec 2021 19:23:09 +0500
Message-Id: <20211207142309.222820-1-amhamza.mgc@gmail.com>
In-Reply-To: <Ya9YxoUqkATCOASh@sirena.org.uk>
References: <Ya9YxoUqkATCOASh@sirena.org.uk>
MIME-Version: 1.0
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Dereferncing of_id pointer will result in exception in current
implementation since of_match_device() will assign it to NULL.
Adding NULL check for protection.

Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
---
changes in v2:
Replace of_match_device() with of_device_get_match_data to simplify the
logic as suggested by Kuninori Morimoto
---
 sound/soc/generic/test-component.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/sound/soc/generic/test-component.c b/sound/soc/generic/test-component.c
index 8fc97d3ff011..5da4725d9e16 100644
--- a/sound/soc/generic/test-component.c
+++ b/sound/soc/generic/test-component.c
@@ -531,17 +531,13 @@ static int test_driver_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct device_node *node = dev->of_node;
 	struct device_node *ep;
-	const struct of_device_id *of_id = of_match_device(test_of_match, &pdev->dev);
-	const struct test_adata *adata;
+	const struct test_adata *adata = of_device_get_match_data(&pdev->dev);
 	struct snd_soc_component_driver *cdriv;
 	struct snd_soc_dai_driver *ddriv;
 	struct test_dai_name *dname;
 	struct test_priv *priv;
 	int num, ret, i;
 
-	if (!of_id)
-		return -EINVAL;
-	adata = of_id->data;
 	num = of_graph_get_endpoint_count(node);
 	if (!num) {
 		dev_err(dev, "no port exits\n");
@@ -552,7 +548,7 @@ static int test_driver_probe(struct platform_device *pdev)
 	cdriv	= devm_kzalloc(dev, sizeof(*cdriv),		GFP_KERNEL);
 	ddriv	= devm_kzalloc(dev, sizeof(*ddriv) * num,	GFP_KERNEL);
 	dname	= devm_kzalloc(dev, sizeof(*dname) * num,	GFP_KERNEL);
-	if (!priv || !cdriv || !ddriv || !dname)
+	if (!priv || !cdriv || !ddriv || !dname || !adata)
 		return -EINVAL;
 
 	priv->dev		= dev;
-- 
2.25.1