Hotfix/sangshuduo/td 3801 taosdump coverity scan issue (#6642)

* [TD-3801]<fix>: taosdump coverity scan issue.

* merge from commit: 069169e7 and fix coverity scan issue.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

src/kit/taosdemo/taosdemo.c

@@ -5098,7 +5098,7 @@ static int32_t generateStbDataTail(
     } else {
         retLen = getRowDataFromSample(
                   data,
-                  remainderBufLen,
+                  remainderBufLen < MAX_DATA_SIZE ? remainderBufLen : MAX_DATA_SIZE,
                   startTime + superTblInfo->timeStampStep * k,
                   superTblInfo,
                   pSamplePos);

src/kit/taosdump/taosdump.c

@@ -29,6 +29,9 @@
 #define COMMAND_SIZE 65536
 //#define DEFAULT_DUMP_FILE "taosdump.sql"
 
+// for strncpy buffer overflow
+#define min(a, b) (((a) < (b)) ? (a) : (b))
+
 int  converStringToReadable(char *str, int size, char *buf, int bufsize);
 int  convertNCharToReadable(char *str, int size, char *buf, int bufsize);
 void taosDumpCharset(FILE *fp);
@@ -1119,12 +1122,11 @@ int taosGetTableDes(
   TAOS_FIELD *fields = taos_fetch_fields(res);
 
   tstrncpy(tableDes->name, table, TSDB_TABLE_NAME_LEN);
-
   while ((row = taos_fetch_row(res)) != NULL) {
     strncpy(tableDes->cols[count].field, (char *)row[TSDB_DESCRIBE_METRIC_FIELD_INDEX],
             fields[TSDB_DESCRIBE_METRIC_FIELD_INDEX].bytes);
     strncpy(tableDes->cols[count].type, (char *)row[TSDB_DESCRIBE_METRIC_TYPE_INDEX],
-            fields[TSDB_DESCRIBE_METRIC_TYPE_INDEX].bytes);
+            min(15, fields[TSDB_DESCRIBE_METRIC_TYPE_INDEX].bytes));
     tableDes->cols[count].length = *((int *)row[TSDB_DESCRIBE_METRIC_LENGTH_INDEX]);
     strncpy(tableDes->cols[count].note, (char *)row[TSDB_DESCRIBE_METRIC_NOTE_INDEX],
             fields[TSDB_DESCRIBE_METRIC_NOTE_INDEX].bytes);
@@ -1575,7 +1577,7 @@ int taosDumpDb(SDbInfo *dbInfo, struct arguments *arguments, FILE *fp, TAOS *tao
     tstrncpy(tableRecord.name, (char *)row[TSDB_SHOW_TABLES_NAME_INDEX],
             fields[TSDB_SHOW_TABLES_NAME_INDEX].bytes);
     tstrncpy(tableRecord.metric, (char *)row[TSDB_SHOW_TABLES_METRIC_INDEX],
-            fields[TSDB_SHOW_TABLES_METRIC_INDEX].bytes);
+            min(TSDB_TABLE_NAME_LEN, fields[TSDB_SHOW_TABLES_METRIC_INDEX].bytes));
 
     taosWrite(fd, &tableRecord, sizeof(STableRecord));