diff --git a/components/zcancmder/zcan_protocol_parser.cpp b/components/zcancmder/zcan_protocol_parser.cpp
index 4923af5..987c6bf 100644
--- a/components/zcancmder/zcan_protocol_parser.cpp
+++ b/components/zcancmder/zcan_protocol_parser.cpp
@@ -1,6 +1,7 @@
 #include "zcan_protocol_parser.hpp"
 
 #include <stdio.h>
+#include <string.h>
 
 #include "sdk/os/zos.hpp"
 
@@ -133,6 +134,8 @@ void ZCanProtocolParser::_onRceivePacket(ZIModule* module, zcr_cmd_header_t* rxc
   cxt.acklen      = 0;
   cxt.ackbuf      = ackbuf;
 
+  memset(ackbuf, 0, sizeof(ackbuf));
+
   int32_t ecode = fn->cb(&cxt);
   if (ecode != 0) {
     m_cancmder->sendErrorAck(rxcmd, ecode);
@@ -147,9 +150,9 @@ void ZCanProtocolParser::_onRceivePacket(ZIModule* module, zcr_cmd_header_t* rxc
   if (module == nullptr) return err::koperation_not_support; \
   if (paraNum >= 0 && paraNum != cxt->paramlen / 4) return err::kcmd_param_num_error;
 
-  #define GET_MODULE(paraNum)                        \
-  auto* module = dynamic_cast<MODULE_CLASS*>(cxt->module);   \
-  if (module == nullptr) return err::koperation_not_support; 
+#define GET_MODULE(paraNum)                                \
+  auto* module = dynamic_cast<MODULE_CLASS*>(cxt->module); \
+  if (module == nullptr) return err::koperation_not_support;
 
 #define MODULE_CLASS ZIModule
 int32_t ZCanProtocolParser::module_ping(cmdcontxt_t* cxt) {
diff --git a/components/zcancmder/zcan_protocol_parser.hpp b/components/zcancmder/zcan_protocol_parser.hpp
index e096023..c7da80e 100644
--- a/components/zcancmder/zcan_protocol_parser.hpp
+++ b/components/zcancmder/zcan_protocol_parser.hpp
@@ -29,7 +29,7 @@ class ZCanProtocolParser : public IZCanReceiverListener {
   IZCanReceiver*           m_cancmder = nullptr;
   map<uint16_t, ZIModule*> m_modulers;
 
-  uint8_t ackbuf[ZCANCMD_READ_BUF_MAX_SIZE + 100];
+  uint8_t ackbuf[ZCANCMD_READ_BUF_MAX_SIZE + 10];
   int32_t acklen = 0;
 
   cmdfn_t cmdfnlist[100];