Index: uspace/srv/devman/driver.c
===================================================================
--- uspace/srv/devman/driver.c	(revision a01f7320d7baed06438e7cde66ccddacc299ba1d)
+++ uspace/srv/devman/driver.c	(revision 5aa06adf17a2a702478c5e98e856235e79264c04)
@@ -462,8 +462,11 @@
 			list_remove(&dev->driver_devices);
 			fibril_mutex_unlock(&driver->driver_mutex);
+			/* Give an extra reference to driver_reassign_fibril */
+			dev_add_ref(dev);
 			fid_t fid = fibril_create(driver_reassign_fibril, dev);
 			if (fid == 0) {
 				log_msg(LOG_DEFAULT, LVL_ERROR,
 				    "Error creating fibril to assign driver.");
+				dev_del_ref(dev);
 			}
 			fibril_add_ready(fid);