Commit 36f597bb authored Jan 08, 2026 by Bartosz Golaszewski

gpiolib: fix lookup table matching

If on any iteration in gpiod_find(), gpio_desc_table_match() returns
NULL (which is normal and expected), we never reinitialize desc back to
ERR_PTR(-ENOENT) and if we don't find a match later on, we will return
NULL causing a NULL-pointer dereference in users not expecting it. Don't
initialize desc, but return ERR_PTR(-ENOENT) explicitly at the end of
the function.

Fixes: 9700b0fc ("gpiolib: allow multiple lookup tables per consumer")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Closes: https://lore.kernel.org/all/00107523-7737-4b92-a785-14ce4e93b8cb@samsung.com/

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20260108102314.18816-1-bartosz.golaszewski@oss.qualcomm.com

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

parent a8020807

drivers/gpio/gpiolib.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -4602,8 +4602,8 @@ static struct gpio_desc gpio_desc_table_match(struct device dev, const char *c
		static struct gpio_desc gpiod_find(struct device dev, const char *con_id,
		unsigned int idx, unsigned long *flags)
		{
		struct gpio_desc *desc = ERR_PTR(-ENOENT);
		struct gpiod_lookup_table *table;
		struct gpio_desc *desc;

		guard(mutex)(&gpio_lookup_lock);

		@@ -4619,7 +4619,7 @@ static struct gpio_desc gpiod_find(struct device dev, const char *con_id,
		return desc;
		}

		return desc;
		return ERR_PTR(-ENOENT);
		}

		static int platform_gpio_count(struct device dev, const char con_id)