[PATCH] bus: imx-weim: fix to avoid potential NULL pointer dereference

[Zhang Shurong]

of_match_device() may fail and returns a NULL pointer.

Fix this by checking the return value of of_match_device.

Fixes: 3f98b6baad63 ("drivers: bus: imx-weim: Add support for i.MX1/21/25/27/31/35/50/51/53")
Signed-off-by: Zhang Shurong <zhang_shurong at foxmail.com>
---
 drivers/bus/imx-weim.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
index 52a5d0447390..65402bb60c18 100644
--- a/drivers/bus/imx-weim.c
+++ b/drivers/bus/imx-weim.c
@@ -202,15 +202,19 @@ static int weim_timing_setup(struct device *dev, struct device_node *np,
 
 static int weim_parse_dt(struct platform_device *pdev)
 {
-	const struct of_device_id *of_id = of_match_device(weim_id_table,
-							   &pdev->dev);
-	const struct imx_weim_devtype *devtype = of_id->data;
+	const struct of_device_id *of_id;
+	const struct imx_weim_devtype *devtype;
 	int ret = 0, have_child = 0;
 	struct device_node *child;
 	struct weim_priv *priv;
 	void __iomem *base;
 	u32 reg;
 
+	of_id = of_match_device(weim_id_table, &pdev->dev);
+	if (!of_id)
+		return -EINVAL;
+
+	devtype = of_id->data;
 	if (devtype == &imx50_weim_devtype) {
 		ret = imx_weim_gpr_setup(pdev);
 		if (ret)
-- 
2.30.2