media: media-device: fix infoleak in ioctl media_enum_entities()

commit e6a62346 upstream.

This fixes CVE-2014-1739.
Signed-off-by: Salva Peiró <speiro@ai2.upv.es>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/media/media-device.c

@@ -90,6 +90,7 @@ static long media_device_enum_entities(struct media_device *mdev,
 	struct media_entity *ent;
 	struct media_entity_desc u_ent;
 
+	memset(&u_ent, 0, sizeof(u_ent));
 	if (copy_from_user(&u_ent.id, &uent->id, sizeof(u_ent.id)))
 		return -EFAULT;