Commit 5607f5ed authored by Dan Carpenter's avatar Dan Carpenter Committed by Bartosz Golaszewski
Browse files

gpio: sysfs: Fix an end of loop test in gpiod_unexport() 



The test for "if (!desc_data)" does not work correctly because the list
iterator in a list_for_each_entry() loop is always non-NULL. If we don't
exit via a break, then it points to invalid memory.  Instead, use a tmp
variable for the list iterator and only set the "desc_data" when we have
found a match.

Fixes: 1cd53df7 ("gpio: sysfs: don't look up exported lines as class devices")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/747545bf-05f0-4f89-ba77-cb96bf9041f1@sabinyo.mountain


Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent ae455b24

drivers/gpio/gpiolib-sysfs.c

+6 −3
Original line number Diff line number Diff line
@@ -927,7 +927,7 @@ EXPORT_SYMBOL_GPL(gpiod_export_link); 
 */

void gpiod_unexport(struct gpio_desc *desc)

{

	struct gpiod_data *desc_data = NULL;

	struct gpiod_data *tmp, *desc_data = NULL;

	struct gpiodev_data *gdev_data;

	struct gpio_device *gdev;
@@ -945,9 +945,12 @@ void gpiod_unexport(struct gpio_desc *desc) 
		if (!gdev_data)

			return;



		list_for_each_entry(desc_data, &gdev_data->exported_lines, list)

			if (gpiod_is_equal(desc, desc_data->desc))

		list_for_each_entry(tmp, &gdev_data->exported_lines, list) {

			if (gpiod_is_equal(desc, tmp->desc)) {

				desc_data = tmp;

				break;

			}

		}



		if (!desc_data)

			return;