diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c
index 73ade0513ccb..65065f7e1499 100644
--- a/drivers/gpu/drm/drm_auth.c
+++ b/drivers/gpu/drm/drm_auth.c
@@ -120,6 +120,10 @@ int drm_authmagic(struct drm_device *dev, void *data,
 	DRM_DEBUG("%u\n", auth->magic);
 
 	down_write(&dev->master_rwsem);
+	if (unlikely(!drm_is_current_master(file_priv))) {
+		up_write(&dev->master_rwsem);
+		return -EACCES;
+	}
 	file = idr_find(&file_priv->master->magic_map, auth->magic);
 	if (file) {
 		file->authenticated = 1;
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 158629d88319..8bea39ffc5c0 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -386,6 +386,10 @@ static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *f
 	int if_version, retcode = 0;
 
 	down_write(&dev->master_rwsem);
+	if (unlikely(!drm_is_current_master(file_priv))) {
+		retcode = -EACCES;
+		goto unlock;
+	}
 	if (sv->drm_di_major != -1) {
 		if (sv->drm_di_major != DRM_IF_MAJOR ||
 		    sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
@@ -420,8 +424,9 @@ static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *f
 	sv->drm_di_minor = DRM_IF_MINOR;
 	sv->drm_dd_major = dev->driver->major;
 	sv->drm_dd_minor = dev->driver->minor;
-	up_write(&dev->master_rwsem);
 
+unlock:
+	up_write(&dev->master_rwsem);
 	return retcode;
 }
 
@@ -574,12 +579,12 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
 	DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0),
 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
-	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
+	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, 0),
 
 	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 	DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
-	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_MASTER),
+	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, 0),
 
 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
@@ -706,10 +711,10 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
 		      DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, 0),
 	DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, 0),
-	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER),
+	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, 0),
 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER),
 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER),
-	DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER),
+	DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, 0),
 };
 
 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
@@ -776,6 +781,9 @@ long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
 	if (unlikely(drm_core_check_feature(dev, DRIVER_LEGACY)) && !(flags & DRM_UNLOCKED))
 		mutex_lock(&drm_global_mutex);
 
+	if (unlikely(flags & DRM_MASTER))
+		down_read(&dev->master_rwsem);
+
 	retcode = drm_ioctl_permit(flags, file_priv);
 	if (unlikely(retcode))
 		goto out;
@@ -783,6 +791,8 @@ long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
 	retcode = func(dev, kdata, file_priv);
 
 out:
+	if (unlikely(flags & DRM_MASTER))
+		up_read(&dev->master_rwsem);
 	if (unlikely(drm_core_check_feature(dev, DRIVER_LEGACY)) && !(flags & DRM_UNLOCKED))
 		mutex_unlock(&drm_global_mutex);
 	return retcode;
diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c
index dee4f24a1808..bed6f7636cbe 100644
--- a/drivers/gpu/drm/drm_lease.c
+++ b/drivers/gpu/drm/drm_lease.c
@@ -500,6 +500,18 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
 		return -EINVAL;
 	}
 
+	/* Clone the lessor file to create a new file for us */
+	DRM_DEBUG_LEASE("Allocating lease file\n");
+	lessee_file = file_clone_open(lessor_file);
+	if (IS_ERR(lessee_file))
+		return PTR_ERR(lessee_file);
+
+	down_read(&dev->master_rwsem);
+	if (unlikely(!drm_is_current_master(lessor_priv))) {
+		ret = -EACCES;
+		goto out_file;
+	}
+
 	lessor = drm_file_get_master(lessor_priv);
 	/* Do not allow sub-leases */
 	if (lessor->lessor) {
@@ -547,14 +559,6 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
 		goto out_leases;
 	}
 
-	/* Clone the lessor file to create a new file for us */
-	DRM_DEBUG_LEASE("Allocating lease file\n");
-	lessee_file = file_clone_open(lessor_file);
-	if (IS_ERR(lessee_file)) {
-		ret = PTR_ERR(lessee_file);
-		goto out_lessee;
-	}
-
 	lessee_priv = lessee_file->private_data;
 	/* Change the file to a master one */
 	drm_master_put(&lessee_priv->master);
@@ -571,17 +575,19 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
 	fd_install(fd, lessee_file);
 
 	drm_master_put(&lessor);
+	up_read(&dev->master_rwsem);
 	DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl succeeded\n");
 	return 0;
 
-out_lessee:
-	drm_master_put(&lessee);
-
 out_leases:
 	put_unused_fd(fd);
 
 out_lessor:
 	drm_master_put(&lessor);
+
+out_file:
+	up_read(&dev->master_rwsem);
+	fput(lessee_file);
 	DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret);
 	return ret;
 }
@@ -705,6 +711,11 @@ int drm_mode_revoke_lease_ioctl(struct drm_device *dev,
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
 		return -EOPNOTSUPP;
 
+	down_write(&dev->master_rwsem);
+	if (unlikely(!drm_is_current_master(lessor_priv))) {
+		ret = -EACCES;
+		goto unlock;
+	}
 	lessor = drm_file_get_master(lessor_priv);
 	mutex_lock(&dev->mode_config.idr_mutex);
 
@@ -728,5 +739,7 @@ int drm_mode_revoke_lease_ioctl(struct drm_device *dev,
 	mutex_unlock(&dev->mode_config.idr_mutex);
 	drm_master_put(&lessor);
 
+unlock:
+	up_write(&dev->master_rwsem);
 	return ret;
 }
diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
index 142fb2f6e74d..7d32bb69e6db 100644
--- a/include/drm/drm_device.h
+++ b/include/drm/drm_device.h
@@ -151,6 +151,11 @@ struct drm_device {
 	 * Lock for &drm_device.master, &drm_file.was_master,
 	 * &drm_file.is_master, &drm_file.master, &drm_master.unique,
 	 * &drm_master.unique_len, and &drm_master.magic_map.
+	 *
+	 * Additionally, synchronizes modesetting rights between multiple users.
+	 * Users that can change the modeset or display state must hold a read
+	 * lock on @master_rwsem, and users that change modesetting rights
+	 * should hold a write lock.
 	 */
 	struct rw_semaphore master_rwsem;
 
