diff options
| author | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2024-10-24 15:38:34 +0200 |
|---|---|---|
| committer | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2024-10-24 20:51:09 +0200 |
| commit | 1f4a640e9ac7f450752365541ad9c064b13ef8bf (patch) | |
| tree | 23fe36bb0548066e513d8a047bf1e3dacf874efe /drivers/gpio/gpiolib.c | |
| parent | 4295f4ccfe8c6e6ac5b631919ba7a4fe89d22acf (diff) | |
gpiolib: fix a NULL-pointer dereference when setting direction
For optional GPIOs we may pass NULL to gpiod_direction_(input|output)().
With the call to the notifier chain added by commit 07c61d4da43f
("gpiolib: notify user-space about in-kernel line state changes") we
will now dereference a NULL pointer in this case. The reason for that is
the fact that the expansion of the VALIDATE_DESC() macro (which returns
0 for NULL descriptors) was moved into the nonotify variants of the
direction setters.
Move them back to the top-level interfaces as the nonotify ones are only
ever called from inside the GPIO core and are always passed valid GPIO
descriptors. This way we'll never call the line_state notifier chain
with non-valid descs.
Fixes: 07c61d4da43f ("gpiolib: notify user-space about in-kernel line state changes")
Reported-by: Mark Brown <broonie@kernel.org>
Closes: https://lore.kernel.org/all/d6601a31-7685-4b21-9271-1b76116cc483@sirena.org.uk/
Tested-by: Klara Modin <klarasmodin@gmail.com>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241024133834.47395-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index ae758ba6dc3d..6001ec96693c 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2695,6 +2695,8 @@ int gpiod_direction_input(struct gpio_desc *desc) { int ret; + VALIDATE_DESC(desc); + ret = gpiod_direction_input_nonotify(desc); if (ret == 0) gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); @@ -2707,8 +2709,6 @@ int gpiod_direction_input_nonotify(struct gpio_desc *desc) { int ret = 0; - VALIDATE_DESC(desc); - CLASS(gpio_chip_guard, guard)(desc); if (!guard.gc) return -ENODEV; @@ -2841,6 +2841,8 @@ int gpiod_direction_output(struct gpio_desc *desc, int value) { int ret; + VALIDATE_DESC(desc); + ret = gpiod_direction_output_nonotify(desc, value); if (ret == 0) gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); @@ -2854,8 +2856,6 @@ int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value) unsigned long flags; int ret; - VALIDATE_DESC(desc); - flags = READ_ONCE(desc->flags); if (test_bit(FLAG_ACTIVE_LOW, &flags)) |