[PATCH xf86-input-libinput v3] Ignore property changes if the device is disabled

[Peter Hutterer]

On Wed, Feb 25, 2015 at 11:49:19AM +0100, Olivier Fourdan wrote:
> If the device is present but disabled, the server will still call into
> SetProperty. We don't have a libinput device to back it up in this case,
> causing a null-pointer dereference.
> 
> This is a bug specific to this driver that cannot easily be fixed. All
> other drivers can handle property changes even if no device is present,
> here we rely on libinput to make the final call. But without a device
> path/fd we don't have a libinput reference.
> 
> The protocol doesn't mention this case, so let's pick BadMatch as the
> least wrong error code. And put a warning in the log, this needs a
> workaround in the client.
> 
> Also, if we get here and the device is on, then that's definitely a bug,
> warn about that.
> 
> https://bugs.freedesktop.org/show_bug.cgi?id=89296
> 
> Signed-off-by: Olivier Fourdan <ofourdan at redhat.com>
> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> ---
> 
>  v3: Check for valid device only for libinput properties

pushed, thanks

   2600a4a..98ae01b  master -> master

Cheers,
   Peter

> 
>  src/libinput.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++------
>  1 file changed, 53 insertions(+), 6 deletions(-)
> 
> diff --git a/src/libinput.c b/src/libinput.c
> index 9613fbd..9afa6d1 100644
> --- a/src/libinput.c
> +++ b/src/libinput.c
> @@ -1293,6 +1293,26 @@ static Atom prop_float;
>  static Atom prop_device;
>  static Atom prop_product_id;
>  
> +static inline BOOL
> +xf86libinput_check_device (DeviceIntPtr dev,
> +			   Atom atom)
> +{
> +	InputInfoPtr pInfo = dev->public.devicePrivate;
> +	struct xf86libinput *driver_data = pInfo->private;
> +	struct libinput_device *device = driver_data->device;
> +
> +	if (device == NULL) {
> +		BUG_WARN(dev->public.on);
> +		xf86IDrvMsg(pInfo, X_INFO,
> +			    "SetProperty on %d called but device is disabled.\n"
> +			    "This driver cannot change properties on a disabled device\n",
> +			    atom);
> +		return FALSE;
> +	}
> +
> +	return TRUE;
> +}
> +
>  static inline int
>  LibinputSetPropertyTap(DeviceIntPtr dev,
>                         Atom atom,
> @@ -1312,6 +1332,9 @@ LibinputSetPropertyTap(DeviceIntPtr dev,
>  		if (*data != 0 && *data != 1)
>  			return BadValue;
>  
> +		if (!xf86libinput_check_device (dev, atom))
> +			return BadMatch;
> +
>  		if (libinput_device_config_tap_get_finger_count(device) == 0)
>  			return BadMatch;
>  	} else {
> @@ -1343,6 +1366,9 @@ LibinputSetPropertyCalibration(DeviceIntPtr dev,
>  		    data[8] != 1)
>  			return BadValue;
>  
> +		if (!xf86libinput_check_device (dev, atom))
> +			return BadMatch;
> +
>  		if (!libinput_device_config_calibration_has_matrix(device))
>  			return BadMatch;
>  	} else {
> @@ -1374,6 +1400,9 @@ LibinputSetPropertyAccel(DeviceIntPtr dev,
>  		if (*data < -1 || *data > 1)
>  			return BadValue;
>  
> +		if (!xf86libinput_check_device (dev, atom))
> +			return BadMatch;
> +
>  		if (libinput_device_config_accel_is_available(device) == 0)
>  			return BadMatch;
>  	} else {
> @@ -1403,6 +1432,9 @@ LibinputSetPropertyNaturalScroll(DeviceIntPtr dev,
>  		if (*data != 0 && *data != 1)
>  			return BadValue;
>  
> +		if (!xf86libinput_check_device (dev, atom))
> +			return BadMatch;
> +
>  		if (libinput_device_config_scroll_has_natural_scroll(device) == 0)
>  			return BadMatch;
>  	} else {
> @@ -1435,9 +1467,12 @@ LibinputSetPropertySendEvents(DeviceIntPtr dev,
>  		modes |= LIBINPUT_CONFIG_SEND_EVENTS_DISABLED_ON_EXTERNAL_MOUSE;
>  
>  	if (checkonly) {
> -		uint32_t supported =
> -			libinput_device_config_send_events_get_modes(device);
> +		uint32_t supported;
> +
> +		if (!xf86libinput_check_device (dev, atom))
> +			return BadMatch;
>  
> +		supported = libinput_device_config_send_events_get_modes(device);
>  		if ((modes | supported) != supported)
>  			return BadValue;
>  
> @@ -1465,9 +1500,13 @@ LibinputSetPropertyLeftHanded(DeviceIntPtr dev,
>  	data = (BOOL*)val->data;
>  
>  	if (checkonly) {
> -		int supported = libinput_device_config_left_handed_is_available(device);
> +		int supported;
>  		int left_handed = *data;
>  
> +		if (!xf86libinput_check_device (dev, atom))
> +			return BadMatch;
> +
> +		supported = libinput_device_config_left_handed_is_available(device);
>  		if (!supported && left_handed)
>  			return BadValue;
>  	} else {
> @@ -1502,11 +1541,15 @@ LibinputSetPropertyScrollMethods(DeviceIntPtr dev,
>  		modes |= LIBINPUT_CONFIG_SCROLL_ON_BUTTON_DOWN;
>  
>  	if (checkonly) {
> -		uint32_t supported = libinput_device_config_scroll_get_methods(device);
> +		uint32_t supported;
>  
>  		if (__builtin_popcount(modes) > 1)
>  			return BadValue;
>  
> +		if (!xf86libinput_check_device (dev, atom))
> +			return BadMatch;
> +
> +		supported = libinput_device_config_scroll_get_methods(device);
>  		if (modes && (modes & supported) == 0)
>  			return BadValue;
>  	} else {
> @@ -1534,9 +1577,13 @@ LibinputSetPropertyScrollButton(DeviceIntPtr dev,
>  
>  	if (checkonly) {
>  		uint32_t button = *data;
> -		uint32_t supported = libinput_device_has_button(device,
> -								btn_xorg2linux(button));
> +		uint32_t supported;
> +
> +		if (!xf86libinput_check_device (dev, atom))
> +			return BadMatch;
>  
> +		supported = libinput_device_has_button(device,
> +						       btn_xorg2linux(button));
>  		if (button && !supported)
>  			return BadValue;
>  	} else {
> -- 
> 2.1.0
>