gpio: GPIO_GET_LINEEVENT_IOCTL: Reject invalid line and event flags

[cascardo/linux.git] / drivers / gpio / gpiolib.c

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index b5b1a84..20e09b7 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -556,6 +556,10 @@ struct lineevent_state {
        struct mutex read_lock;
 };
 
+#define GPIOEVENT_REQUEST_VALID_FLAGS \
+       (GPIOEVENT_REQUEST_RISING_EDGE | \
+       GPIOEVENT_REQUEST_FALLING_EDGE)
+
 static unsigned int lineevent_poll(struct file *filep,
                                   struct poll_table_struct *wait)
 {
@@ -753,6 +757,13 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
                goto out_free_label;
        }
 
+       /* Return an error if a unknown flag is set */
+       if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
+           (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
+               ret = -EINVAL;
+               goto out_free_label;
+       }
+
        /* This is just wrong: we don't look for events on output lines */
        if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
                ret = -EINVAL;