[PATCH] io: adc: stm32-adc: fix potential NULL pointer dereference in stm32_adc_probe()

[Zhang Shurong]

of_match_device() may fail and returns a NULL pointer.

Fix this by checking the return value of of_match_device().

Fixes: 64ad7f6438f3 ("iio: adc: stm32: introduce compatible data cfg")
Signed-off-by: Zhang Shurong <zhang_shurong@xxxxxxxxxxx>
---
 drivers/iio/adc/stm32-adc-core.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c
index 48f02dcc81c1..70011fdbf5f6 100644
--- a/drivers/iio/adc/stm32-adc-core.c
+++ b/drivers/iio/adc/stm32-adc-core.c
@@ -706,6 +706,8 @@ static int stm32_adc_probe(struct platform_device *pdev)
 	struct stm32_adc_priv *priv;
 	struct device *dev = &pdev->dev;
 	struct device_node *np = pdev->dev.of_node;
+	const struct of_device_id *of_id;
+
 	struct resource *res;
 	u32 max_rate;
 	int ret;
@@ -718,8 +720,11 @@ static int stm32_adc_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	platform_set_drvdata(pdev, &priv->common);
 
-	priv->cfg = (const struct stm32_adc_priv_cfg *)
-		of_match_device(dev->driver->of_match_table, dev)->data;
+	of_id = of_match_device(dev->driver->of_match_table, dev);
+	if (!of_id)
+		return -ENODEV;
+
+	priv->cfg = (const struct stm32_adc_priv_cfg *)of_id->data;
 	priv->nb_adc_max = priv->cfg->num_adcs;
 	spin_lock_init(&priv->common.lock);
 
-- 
2.30.2