diff options
| author | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2025-02-10 11:51:56 +0100 |
|---|---|---|
| committer | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2025-02-24 09:58:58 +0100 |
| commit | 69920338f8130da929ade6f93e6fa3e0e68433ee (patch) | |
| tree | 2756984d79627a1b8b7172a79c21d79d1d56efe6 | |
| parent | 2d13f801f1a67e9e19ccb810dc4f56870f4e9704 (diff) | |
gpiolib: sanitize the return value of gpio_chip::request()
The return value of the request() 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-v1-2-12ea88506cb2@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
| -rw-r--r-- | drivers/gpio/gpiolib.c | 2 | ||||
| -rw-r--r-- | include/linux/gpio/driver.h | 3 |
2 files changed, 4 insertions, 1 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index fea0cdec0b26..a98025b0ecf7 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2349,6 +2349,8 @@ static int gpiod_request_commit(struct gpio_desc *desc, const char *label) ret = guard.gc->request(guard.gc, offset); else ret = -EINVAL; + if (ret > 0) + ret = -EBADE; if (ret) goto out_clear_bit; } diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 10544f4a03e5..ce22c072337c 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -329,7 +329,8 @@ struct gpio_irq_chip { * @fwnode: optional fwnode providing this controller's properties * @owner: helps prevent removal of modules exporting active GPIOs * @request: optional hook for chip-specific activation, such as - * enabling module power and clock; may sleep + * enabling module power and clock; may sleep; must return 0 on success + * or negative error number on failure * @free: optional hook for chip-specific deactivation, such as * disabling module power and clock; may sleep * @get_direction: returns direction for signal "offset", 0=out, 1=in, |