diff --git a/src/client/inc/tsclient.h b/src/client/inc/tsclient.h
index 85bdfa43fdf164ac2a3a51b5d8bba047821267c0..2b3f928993a3cdd73d5e6fd4aed607c0efe372cc 100644
--- a/src/client/inc/tsclient.h
+++ b/src/client/inc/tsclient.h
@@ -386,6 +386,7 @@ typedef struct SSqlObj {
   SSqlRes          res;
 
   SSubqueryState   subState;
+  pthread_mutex_t  mtxSubs;      // avoid double access pSubs after failure
   struct SSqlObj **pSubs;
   struct SSqlObj  *rootObj;
 
diff --git a/src/client/src/tscAsync.c b/src/client/src/tscAsync.c
index 911da05b4379ad871a09db6f7b87d26712051e02..5cd81517e42839fe0f31c438832b1b602bf782f9 100644
--- a/src/client/src/tscAsync.c
+++ b/src/client/src/tscAsync.c
@@ -46,6 +46,8 @@ void doAsyncQuery(STscObj* pObj, SSqlObj* pSql, __async_cb_func_t fp, void* para
   pSql->fetchFp   = fp;
   pSql->rootObj   = pSql;
 
+  pthread_mutex_init(&pSql->mtxSubs, NULL);
+
   registerSqlObj(pSql);
 
   pSql->sqlstr = calloc(1, sqlLen + 1);
diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index c4c7311fe7a2c0725483ac9edc7c476e3c57beff..6c40629213bb89db0173392a741bfd1f07049663 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -3165,7 +3165,9 @@ int tscRenewTableMeta(SSqlObj *pSql) {
   pSql->rootObj->retryReason = pSql->retryReason;
 
   SSqlObj *rootSql = pSql->rootObj;
+  pthread_mutex_lock(&rootSql->mtxSubs);
   tscFreeSubobj(rootSql);
+  pthread_mutex_unlock(&rootSql->mtxSubs);
   tfree(rootSql->pSubs);
   tscResetSqlCmd(&rootSql->cmd, true, rootSql->self);
 
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 70634a938109d883573f930224e6364b02dc0c02..7bf51d898dbc40991ffb1a4d356b3e26044c1e76 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -1738,6 +1738,10 @@ void tscFreeSqlObj(SSqlObj* pSql) {
 
   tscFreeSubobj(pSql);
 
+  if (pSql && (pSql == pSql->rootObj)) {
+    pthread_mutex_destroy(&pSql->mtxSubs);
+  }
+
   pSql->signature = NULL;
   pSql->fp = NULL;
   tfree(pSql->sqlstr);