using cv destroy instead of free like a dumbass:

kern/synchprobs/traffic_synch.c

@@ -118,7 +118,7 @@ static void clearint(car * done)
     lock_acquire(globlock);
     cv_broadcast(temp->cv, globlock); // wake all/inform them you're all good
     lock_release(globlock);
-    kfree(temp->cv);
+    cv_destroy(temp->cv);
   }
   
   kfree(temp);
@@ -132,7 +132,7 @@ static void dellist(list * dead)
   while (temp)
   {
     car * temp2 = temp->next;
-    kfree(temp->cv);
+    cv_destroy(temp->cv);
     kfree(temp);
     temp = temp2;
   }