Merge tag 'gpio-fixes-for-v5.12-rc8' of git://git.kernel.org/pub/scm/…

…linux/kernel/git/brgl/linux

Pull gpio fix from Bartosz Golaszewski:
 "A single fix for an older problem with the sysfs interface: do not
  allow exporting GPIO lines which were marked invalid by the driver"

* tag 'gpio-fixes-for-v5.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpio: sysfs: Obey valid_mask

drivers/gpio/gpiolib-sysfs.c

@@ -458,6 +458,8 @@ static ssize_t export_store(struct class *class,
 	long			gpio;
 	struct gpio_desc	*desc;
 	int			status;
+	struct gpio_chip	*gc;
+	int			offset;
 
 	status = kstrtol(buf, 0, &gpio);
 	if (status < 0)
@@ -469,6 +471,12 @@ static ssize_t export_store(struct class *class,
 		pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
 		return -EINVAL;
 	}
+	gc = desc->gdev->chip;
+	offset = gpio_chip_hwgpio(desc);
+	if (!gpiochip_line_is_valid(gc, offset)) {
+		pr_warn("%s: GPIO %ld masked\n", __func__, gpio);
+		return -EINVAL;
+	}
 
 	/* No extra locking here; FLAG_SYSFS just signifies that the
 	 * request and export were done by on behalf of userspace, so