diff --git a/source/common/src/tdatablock.c b/source/common/src/tdatablock.c
index 8e50c943b9..718763e063 100644
--- a/source/common/src/tdatablock.c
+++ b/source/common/src/tdatablock.c
@@ -3036,6 +3036,11 @@ int32_t blockDecode(SSDataBlock* pBlock, const char* pData, const char** pEndPos
   // total rows sizeof(int32_t)
   int32_t numOfRows = *(int32_t*)pStart;
   pStart += sizeof(int32_t);
+  if (numOfRows <= 0) {
+    uError("block decode numOfRows:%d error", numOfRows);
+    terrno = TSDB_CODE_QRY_EXECUTOR_INTERNAL_ERROR;
+    return terrno;
+  }
 
   // total columns sizeof(int32_t)
   int32_t numOfCols = *(int32_t*)pStart;
@@ -3084,8 +3089,9 @@ int32_t blockDecode(SSDataBlock* pBlock, const char* pData, const char** pEndPos
 
   for (int32_t i = 0; i < numOfCols; ++i) {
     colLen[i] = htonl(colLen[i]);
-    if (colLen[i] < 0) {
+    if (colLen[i] <= 0) {
       uError("block decode colLen:%d error, colIdx:%d", colLen[i], i);
+      ASSERT(0);
       terrno = TSDB_CODE_QRY_EXECUTOR_INTERNAL_ERROR;
       return terrno;
     }