From b99b9986b8343fb9cdce2ce77334e4ea0e152e12 Mon Sep 17 00:00:00 2001
From: wangmm0220 <wangmm0220@gmail.com>
Date: Mon, 11 Dec 2023 19:46:51 +0800
Subject: [PATCH] fix:heap overflow if print json value node

---
 source/libs/scalar/src/scalar.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/source/libs/scalar/src/scalar.c b/source/libs/scalar/src/scalar.c
index 90cec4522f..b1cd10eac9 100644
--- a/source/libs/scalar/src/scalar.c
+++ b/source/libs/scalar/src/scalar.c
@@ -1367,8 +1367,8 @@ EDealRes sclRewriteCaseWhen(SNode **pNode, SScalarCtx *ctx) {
   } else {
     int32_t type = output.columnData->info.type;
     if (IS_VAR_DATA_TYPE(type)) {  // todo refactor
-      res->datum.p = output.columnData->pData;
-      output.columnData->pData = NULL;
+      res->datum.p = taosMemoryCalloc(varDataTLen(output.columnData->pData) + 1, sizeof(char));      // add \0 to the end for print json value
+      memcpy(res->datum.p, output.columnData->pData, varDataTLen(output.columnData->pData));
     } else {
       nodesSetValueNodeValue(res, output.columnData->pData);
     }