Index: uspace/srv/devman/driver.c
===================================================================
--- uspace/srv/devman/driver.c	(revision 64f85f54a27d11f2ce4cf0aef2e2fb35918fe5cd)
+++ uspace/srv/devman/driver.c	(revision b501de784dd26902c687e3142fa124f7aecd3384)
@@ -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);