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 <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20250210-gpio-sanitize-retvals-v1-4-12ea88506cb2@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
This commit is contained in:
Bartosz Golaszewski 2025-02-10 11:51:58 +01:00
parent dcf8f3bffa
commit 86ef402d80

View File

@ -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);