fix: invalid read after teardown udfs and close uv pipe later

source/libs/function/src/tudf.c

@@ -1183,7 +1183,9 @@ void onUdfcPipeClose(uv_handle_t *handle) {
     QUEUE_REMOVE(&task->procTaskQueue);
     uv_sem_post(&task->taskSem);
   }
-  conn->session->udfUvPipe = NULL;
+  if (conn->session != NULL) {
+    conn->session->udfUvPipe = NULL;
+  }
   taosMemoryFree(conn->readBuf.buf);
   taosMemoryFree(conn);
   taosMemoryFree((uv_pipe_t *) handle);
@@ -1821,7 +1823,10 @@ int32_t doTeardownUdf(UdfcFuncHandle handle) {
   udfcRunUdfUvTask(task, UV_TASK_DISCONNECT);
 
   fnInfo("tear down udf. udf name: %s, udf func handle: %p", session->udfName, handle);
-
+  if (session->udfUvPipe->data != NULL) {
+    SClientUvConn *conn = session->udfUvPipe->data;
+    conn->session = NULL;
+  }
   taosMemoryFree(session);
   taosMemoryFree(task);