6.14-stable review patch. If anyone has any objections, please let me know.
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From: Bartosz Golaszewski bartosz.golaszewski@linaro.org
[ Upstream commit dcf8f3bffa2de2c7f3b5771b63605194ccd2286f ]
The return value of the set_config() callback may be propagated to user-space. If a bad driver returns a positive number, it may confuse user programs. Tighten the API contract and check for positive numbers returned by GPIO controllers.
Reviewed-by: Linus Walleij linus.walleij@linaro.org Link: https://lore.kernel.org/r/20250210-gpio-sanitize-retvals-v1-3-12ea88506cb2@l... Signed-off-by: Bartosz Golaszewski bartosz.golaszewski@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpio/gpiolib.c | 3 +++ include/linux/gpio/driver.h | 3 ++- 2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 0c00ed2ab4315..960ca0ad45fc8 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2577,6 +2577,9 @@ int gpio_do_set_config(struct gpio_desc *desc, unsigned long config) return -ENOTSUPP;
ret = guard.gc->set_config(guard.gc, gpio_chip_hwgpio(desc), config); + if (ret > 0) + ret = -EBADE; + #ifdef CONFIG_GPIO_CDEV /* * Special case - if we're setting debounce period, we need to store diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 2dd7cb9cc270a..5ce6b2167f808 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -347,7 +347,8 @@ struct gpio_irq_chip { * @set: assigns output value for signal "offset" * @set_multiple: assigns output values for multiple signals defined by "mask" * @set_config: optional hook for all kinds of settings. Uses the same - * packed config format as generic pinconf. + * packed config format as generic pinconf. Must return 0 on success and + * a negative error number on failure. * @to_irq: optional hook supporting non-static gpiod_to_irq() mappings; * implementation may not sleep * @dbg_show: optional routine to show contents in debugfs; default code