gpio: grgpio: Add NULL check in grgpio_probe

devm_kasprintf() can return a NULL pointer on failure,but this
returned value in grgpio_probe is not checked.
Add NULL check in grgpio_probe, to handle kernel NULL
pointer dereference error.

Cc: [email protected]
Fixes: 7eb6ce2 ("gpio: Convert to using %pOF instead of full_name")
Signed-off-by: Charles Han <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bartosz Golaszewski <[email protected]>

Author: Charles Han

drivers/gpio/gpio-grgpio.c

@@ -369,6 +369,9 @@ static int grgpio_probe(struct platform_device *ofdev)
 	gc->owner = THIS_MODULE;
 	gc->to_irq = grgpio_to_irq;
 	gc->label = devm_kasprintf(dev, GFP_KERNEL, "%pOF", np);
+	if (!gc->label)
+		return -ENOMEM;
+
 	gc->base = -1;
 
 	err = of_property_read_u32(np, "nbits", &prop);