gpio: fix line flag validation in lineevent_create

commit 5ca2f54b597c816df54ff1b28eb99cf7262b955d upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 0ca8f3e..6008a30 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -797,7 +797,9 @@ 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;
        }
@@ -811,10 +813,6 @@ 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)