gpio: fix line flag validation in lineevent_create

lineevent_create should not allow any of GPIOHANDLE_REQUEST_OUTPUT,
GPIOHANDLE_REQUEST_OPEN_DRAIN or GPIOHANDLE_REQUEST_OPEN_SOURCE to be set.

Fixes: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 7502230a4ec8ac320bcabcbfe3ee3a5edba0dd05..d9074191edef4da533d27673660e6f357df32fe7 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -934,7 +934,9 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
        }
 
        /* This is just wrong: we don't look for events on output lines */
-       if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
+       if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) ||
+           (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
+           (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) {
                ret = -EINVAL;
                goto out_free_label;
        }
@@ -948,10 +950,6 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
 
        if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
                set_bit(FLAG_ACTIVE_LOW, &desc->flags);
-       if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
-               set_bit(FLAG_OPEN_DRAIN, &desc->flags);
-       if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
-               set_bit(FLAG_OPEN_SOURCE, &desc->flags);
 
        ret = gpiod_direction_input(desc);
        if (ret)