[PATCH] gpiolib: check validity for gpio_info in *_active()

[Uwe Kleine-König]

gpio_set_active, gpio_is_active and gpio_direction_active are public
functions, accordingly there should be error checking.

If an invalid gpio number is given to these functions without checking
gpio_adjust_value is called with gi == NULL which then dereferences this
pointer.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
---
 drivers/gpio/gpiolib.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 67d771bae3a8..c17cfdbb3350 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -204,6 +204,10 @@ EXPORT_SYMBOL(gpio_set_value);
 void gpio_set_active(unsigned gpio, bool value)
 {
 	struct gpio_info *gi = gpio_to_desc(gpio);
+
+	if (!gi)
+		return;
+
 	gpio_set_value(gpio, gpio_adjust_value(gi, value));
 }
 EXPORT_SYMBOL(gpio_set_active);
@@ -229,6 +233,10 @@ EXPORT_SYMBOL(gpio_get_value);
 int gpio_is_active(unsigned gpio)
 {
 	struct gpio_info *gi = gpio_to_desc(gpio);
+
+	if (!gi)
+		return;
+
 	return gpio_adjust_value(gi, gpio_get_value(gpio));
 }
 EXPORT_SYMBOL(gpio_is_active);
@@ -255,6 +263,10 @@ EXPORT_SYMBOL(gpio_direction_output);
 int gpio_direction_active(unsigned gpio, bool value)
 {
 	struct gpio_info *gi = gpio_to_desc(gpio);
+
+	if (!gi)
+		return;
+
 	return gpio_direction_output(gpio, gpio_adjust_value(gi, value));
 }
 EXPORT_SYMBOL(gpio_direction_active);
-- 
2.11.0