gpio: 74xx: fix a possible NULL dereference

of_match_device could return NULL, and so cause a NULL pointer
dereference later at line 132:
priv->flags = (uintptr_t) of_id->data;

Reported-by: coverity (CID 1324141)
Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/gpio/gpio-74xx-mmio.c b/drivers/gpio/gpio-74xx-mmio.c
index 6ed7c0fb3378..6b186829087c 100644
--- a/drivers/gpio/gpio-74xx-mmio.c
+++ b/drivers/gpio/gpio-74xx-mmio.c
@@ -113,13 +113,16 @@ static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 
 static int mmio_74xx_gpio_probe(struct platform_device *pdev)
 {
-        const struct of_device_id *of_id =
-                of_match_device(mmio_74xx_gpio_ids, &pdev->dev);
+        const struct of_device_id *of_id;
         struct mmio_74xx_gpio_priv *priv;
         struct resource *res;
         void __iomem *dat;
         int err;
 
+        of_id = of_match_device(mmio_74xx_gpio_ids, &pdev->dev);
+        if (!of_id)
+                return -ENODEV;
+
         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
         if (!priv)
                 return -ENOMEM;