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>

diff --git a/drivers/gpio/gpio-74xx-mmio.c b/drivers/gpio/gpio-74xx-mmio.c
index 6ed7c0f..6b18682 100644 (file)
--- 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;