diff --git a/components/net/at/src/at_client.c b/components/net/at/src/at_client.c
index 81416be90b..a613ea1435 100644
--- a/components/net/at/src/at_client.c
+++ b/components/net/at/src/at_client.c
@@ -8,6 +8,7 @@
  * 2018-03-30     chenyong     first version
  * 2018-04-12     chenyong     add client implement
  * 2018-08-17     chenyong     multiple client support
+ * 2021-03-17     Meco Man     fix a buf of leaking memory 
  */
 
 #include <at.h>