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gpiolib: Fix Oops in gpiod_direction_input_nonotify()

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The gpiod_direction_input_nonotify() function is supposed to return zero
if the direction for the pin is input.  But instead it accidentally
returns GPIO_LINE_DIRECTION_IN (1) which will be cast into an ERR_PTR()
in gpiochip_request_own_desc().  The callers dereference it and it leads
to a crash.

I changed gpiod_direction_output_raw_commit() just for consistency but
returning GPIO_LINE_DIRECTION_OUT (0) is fine.

Cc: stable@vger.kernel.org
Fixes: 9d846b1aeb ("gpiolib: check the return value of gpio_chip::get_direction()")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/254f3925-3015-4c9d-aac5-bb9b4b2cd2c5@stanley.mountain
[Bartosz: moved the variable declarations to the top of the functions]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
This commit is contained in:
Dan Carpenter 2025-02-28 16:03:47 +03:00 • committed by Bartosz Golaszewski
parent d082ecbc71
commit 64407f4b58
1 changed files with 10 additions and 10 deletions
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20
drivers/gpio/gpiolib.c
View file

@ -2712,7 +2712,7 @@ EXPORT_SYMBOL_GPL(gpiod_direction_input);
int gpiod_direction_input_nonotify(struct gpio_desc *desc)
{
int ret = 0;
int ret = 0, dir;
CLASS(gpio_chip_guard, guard)(desc);
if (!guard.gc)
@ -2740,12 +2740,12 @@ int gpiod_direction_input_nonotify(struct gpio_desc *desc)
ret = guard.gc->direction_input(guard.gc,
gpio_chip_hwgpio(desc));
} else if (guard.gc->get_direction) {
ret = guard.gc->get_direction(guard.gc,
dir = guard.gc->get_direction(guard.gc,
gpio_chip_hwgpio(desc));
if (ret < 0)
return ret;
if (dir < 0)
return dir;
if (ret != GPIO_LINE_DIRECTION_IN) {
if (dir != GPIO_LINE_DIRECTION_IN) {
gpiod_warn(desc,
"%s: missing direction_input() operation and line is output\n",
__func__);
@ -2764,7 +2764,7 @@ int gpiod_direction_input_nonotify(struct gpio_desc *desc)
static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
{
int val = !!value, ret = 0;
int val = !!value, ret = 0, dir;
CLASS(gpio_chip_guard, guard)(desc);
if (!guard.gc)
@ -2788,12 +2788,12 @@ static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
} else {
/* Check that we are in output mode if we can */
if (guard.gc->get_direction) {
ret = guard.gc->get_direction(guard.gc,
dir = guard.gc->get_direction(guard.gc,
gpio_chip_hwgpio(desc));
if (ret < 0)
return ret;
if (dir < 0)
return dir;
if (ret != GPIO_LINE_DIRECTION_OUT) {
if (dir != GPIO_LINE_DIRECTION_OUT) {
gpiod_warn(desc,
"%s: missing direction_output() operation\n",
__func__);