From: Bartosz Golaszewski Date: Mon, 10 Feb 2025 10:51:58 +0000 (+0100) Subject: gpiolib: sanitize the return value of gpio_chip::get() X-Git-Tag: v6.15-rc1~179^2~85 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=86ef402d805d606a10e6da8e5a64a51f6f5fb7e2;p=thirdparty%2Flinux.git gpiolib: sanitize the return value of gpio_chip::get() As per the API contract, the get() callback is only allowed to return 0, 1 or a negative error number. Add a wrapper around the callback calls that filters out anything else. Reviewed-by: Linus Walleij Link: https://lore.kernel.org/r/20250210-gpio-sanitize-retvals-v1-4-12ea88506cb2@linaro.org Signed-off-by: Bartosz Golaszewski --- diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 67a735d579427..1a3f527aba0ea 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -3115,9 +3115,25 @@ void gpiod_toggle_active_low(struct gpio_desc *desc) } EXPORT_SYMBOL_GPL(gpiod_toggle_active_low); +static int gpiochip_get(struct gpio_chip *gc, unsigned int offset) +{ + int ret; + + lockdep_assert_held(&gc->gpiodev->srcu); + + if (!gc->get) + return -EIO; + + ret = gc->get(gc, offset); + if (ret > 1) + ret = -EBADE; + + return ret; +} + static int gpio_chip_get_value(struct gpio_chip *gc, const struct gpio_desc *desc) { - return gc->get ? gc->get(gc, gpio_chip_hwgpio(desc)) : -EIO; + return gpiochip_get(gc, gpio_chip_hwgpio(desc)); } /* I/O calls are only valid after configuration completed; the relevant @@ -3174,7 +3190,7 @@ static int gpio_chip_get_multiple(struct gpio_chip *gc, int i, value; for_each_set_bit(i, mask, gc->ngpio) { - value = gc->get(gc, i); + value = gpiochip_get(gc, i); if (value < 0) return value; __assign_bit(i, bits, value);