data processing net/tracker: return only valid nodes, check for NULL in pointer argument

lib/data_proc_net.c

@@ -215,13 +215,13 @@ struct proc_tracker *pn_get_next_pending_tracker(struct proc_net *pn)
 		if (cnt++ > pn->n)
 			break;
 
-		if (!pt_track_tasks_pending(pt))
-			pn_node_to_queue_tail(pn, pt);
-		else
-			break;
+		if (pt_track_tasks_pending(pt))
+			return pt;
+
+		pn_node_to_queue_tail(pn, pt);
 	}
 
-	return pt;
+	return NULL;
 }
 
 

lib/data_proc_tracker.c

@@ -152,6 +152,8 @@ struct proc_task *pt_track_get(struct proc_tracker *pt)
 {
 	struct proc_task *t;
 
+	if (!pt)
+		return NULL;
 
 	if (list_empty(&pt->tasks))
 		return NULL;