Use memory safe snprintf() in Connect Engine and elsewhere (#2210)

Continue with similar changes as done in 19af1890 to replace sprintf(buf, ...)
with snprintf(buf, sizeof(buf), ...), specifically in the "easy" cases where buf
is allocated with a size known at compile time.

All new code of the whole pull request, including one or several files that are
either new files or modified ones, are contributed under the BSD-new license.  I
am contributing on behalf of my employer Amazon Web Services, Inc.

13 files changed, 70 insertions, 61 deletions

diff --git a/client/mysqlshow.c b/client/mysqlshow.c
index dfa1eac3673..d4085988342 100644
--- a/client/mysqlshow.c
+++ b/client/mysqlshow.c
@@ -449,7 +449,7 @@ list_dbs(MYSQL *mysql,const char *wild)
 	MYSQL_RES *tresult = mysql_list_tables(mysql,(char*)NULL);
 	if (mysql_affected_rows(mysql) > 0)
 	{
-	  sprintf(tables,"%6lu",(ulong) mysql_affected_rows(mysql));
+	  snprintf(tables, sizeof(tables), "%6lu",(ulong) mysql_affected_rows(mysql));
 	  rowcount = 0;
 	  if (opt_verbose > 1)
 	  {
@@ -470,13 +470,13 @@ list_dbs(MYSQL *mysql,const char *wild)
 		}
 	      }
 	    }
-	    sprintf(rows,"%12lu",rowcount);
+	    snprintf(rows, sizeof(rows), "%12lu", rowcount);
 	  }
 	}
 	else
 	{
-	  sprintf(tables,"%6d",0);
-	  sprintf(rows,"%12d",0);
+	  snprintf(tables, sizeof(tables), "%6d" ,0);
+	  snprintf(rows, sizeof(rows), "%12d", 0);
 	}
 	mysql_free_result(tresult);
       }
@@ -594,7 +594,7 @@ list_tables(MYSQL *mysql,const char *db,const char *table)
 	}
 	else
 	{
-	  sprintf(fields,"%8u",(uint) mysql_num_fields(rresult));
+	  snprintf(fields, sizeof(fields), "%8u", (uint) mysql_num_fields(rresult));
 	  mysql_free_result(rresult);
 
 	  if (opt_verbose > 1)
@@ -610,10 +610,10 @@ list_tables(MYSQL *mysql,const char *db,const char *table)
 		rowcount += (unsigned long) strtoull(rrow[0], (char**) 0, 10);
 		mysql_free_result(rresult);
 	      }
-	      sprintf(rows,"%10lu",rowcount);
+	      snprintf(rows, sizeof(rows), "%10lu", rowcount);
 	    }
 	    else
-	      sprintf(rows,"%10d",0);
+	      snprintf(rows, sizeof(rows), "%10d", 0);
 	  }
 	}
       }
diff --git a/sql/sql_analyse.cc b/sql/sql_analyse.cc
index 65049348869..6b2b9c3de85 100644
--- a/sql/sql_analyse.cc
+++ b/sql/sql_analyse.cc
@@ -412,7 +412,7 @@ void field_real::add()
 
   if ((decs = decimals()) >= FLOATING_POINT_DECIMALS)
   {
-    length= sprintf(buff, "%g", num);
+    length= snprintf(buff, sizeof(buff), "%g", num);
     if (rint(num) != num)
       max_notzero_dec_len = 1;
   }
@@ -423,7 +423,7 @@ void field_real::add()
     snprintf(buff, sizeof(buff)-1, "%-.*f", (int) decs, num);
     length = (uint) strlen(buff);
 #else
-    length= sprintf(buff, "%-.*f", (int) decs, num);
+    length= snprintf(buff, sizeof(buff), "%-.*f", (int) decs, num);
 #endif
 
     // We never need to check further than this
@@ -810,32 +810,32 @@ void field_str::get_opt_type(String *answer, ha_rows total_rows)
   if (can_be_still_num)
   {
     if (num_info.is_float)
-      sprintf(buff, "DOUBLE");	  // number was like 1e+50... TODO:
+      snprintf(buff, sizeof(buff), "DOUBLE");	  // number was like 1e+50... TODO:
     else if (num_info.decimals) // DOUBLE(%d,%d) sometime
     {
       if (num_info.dval > -FLT_MAX && num_info.dval < FLT_MAX)
-	sprintf(buff, "FLOAT(%d,%d)", (num_info.integers + num_info.decimals), num_info.decimals);
+	snprintf(buff, sizeof(buff), "FLOAT(%d,%d)", (num_info.integers + num_info.decimals), num_info.decimals);
       else
-	sprintf(buff, "DOUBLE(%d,%d)", (num_info.integers + num_info.decimals), num_info.decimals);
+	snprintf(buff, sizeof(buff), "DOUBLE(%d,%d)", (num_info.integers + num_info.decimals), num_info.decimals);
     }
     else if (ev_num_info.llval >= -128 &&
 	     ev_num_info.ullval <=
 	     (ulonglong) (ev_num_info.llval >= 0 ? 255 : 127))
-      sprintf(buff, "TINYINT(%d)", num_info.integers);
+      snprintf(buff, sizeof(buff), "TINYINT(%d)", num_info.integers);
     else if (ev_num_info.llval >= INT_MIN16 &&
 	     ev_num_info.ullval <= (ulonglong) (ev_num_info.llval >= 0 ?
 						UINT_MAX16 : INT_MAX16))
-      sprintf(buff, "SMALLINT(%d)", num_info.integers);
+      snprintf(buff, sizeof(buff), "SMALLINT(%d)", num_info.integers);
     else if (ev_num_info.llval >= INT_MIN24 &&
 	     ev_num_info.ullval <= (ulonglong) (ev_num_info.llval >= 0 ?
 						UINT_MAX24 : INT_MAX24))
-      sprintf(buff, "MEDIUMINT(%d)", num_info.integers);
+      snprintf(buff, sizeof(buff), "MEDIUMINT(%d)", num_info.integers);
     else if (ev_num_info.llval >= INT_MIN32 &&
 	     ev_num_info.ullval <= (ulonglong) (ev_num_info.llval >= 0 ?
 						UINT_MAX32 : INT_MAX32))
-      sprintf(buff, "INT(%d)", num_info.integers);
+      snprintf(buff, sizeof(buff), "INT(%d)", num_info.integers);
     else
-      sprintf(buff, "BIGINT(%d)", num_info.integers);
+      snprintf(buff, sizeof(buff), "BIGINT(%d)", num_info.integers);
     answer->append(buff, (uint) strlen(buff));
     if (ev_num_info.llval >= 0 && ev_num_info.min_dval >= 0)
       answer->append(STRING_WITH_LEN(" UNSIGNED"));
@@ -853,12 +853,12 @@ void field_str::get_opt_type(String *answer, ha_rows total_rows)
     }
     else if ((max_length * (total_rows - nulls)) < (sum + total_rows))
     {
-      sprintf(buff, "CHAR(%d)", (int) max_length);
+      snprintf(buff, sizeof(buff), "CHAR(%d)", (int) max_length);
       answer->append(buff, (uint) strlen(buff));
     }
     else
     {
-      sprintf(buff, "VARCHAR(%d)", (int) max_length);
+      snprintf(buff, sizeof(buff), "VARCHAR(%d)", (int) max_length);
       answer->append(buff, (uint) strlen(buff));
     }
   }
@@ -897,18 +897,18 @@ void field_real::get_opt_type(String *answer,
 				 0 : (item->decimals + 1));
 
     if (min_arg >= -128 && max_arg <= (min_arg >= 0 ? 255 : 127))
-      sprintf(buff, "TINYINT(%d)", len);
+      snprintf(buff, sizeof(buff), "TINYINT(%d)", len);
     else if (min_arg >= INT_MIN16 && max_arg <= (min_arg >= 0 ?
 						 UINT_MAX16 : INT_MAX16))
-      sprintf(buff, "SMALLINT(%d)", len);
+      snprintf(buff, sizeof(buff), "SMALLINT(%d)", len);
     else if (min_arg >= INT_MIN24 && max_arg <= (min_arg >= 0 ?
 						 UINT_MAX24 : INT_MAX24))
-      sprintf(buff, "MEDIUMINT(%d)", len);
+      snprintf(buff, sizeof(buff), "MEDIUMINT(%d)", len);
     else if (min_arg >= INT_MIN32 && max_arg <= (min_arg >= 0 ?
 						 UINT_MAX32 : INT_MAX32))
-      sprintf(buff, "INT(%d)", len);
+      snprintf(buff, sizeof(buff), "INT(%d)", len);
     else
-      sprintf(buff, "BIGINT(%d)", len);
+      snprintf(buff, sizeof(buff), "BIGINT(%d)", len);
     answer->append(buff, (uint) strlen(buff));
     if (min_arg >= 0)
       answer->append(STRING_WITH_LEN(" UNSIGNED"));
@@ -923,10 +923,10 @@ void field_real::get_opt_type(String *answer,
   else
   {
     if (min_arg >= -FLT_MAX && max_arg <= FLT_MAX)
-      sprintf(buff, "FLOAT(%d,%d)", (int) max_length - (item->decimals + 1) + max_notzero_dec_len,
+      snprintf(buff, sizeof(buff), "FLOAT(%d,%d)", (int) max_length - (item->decimals + 1) + max_notzero_dec_len,
 	      max_notzero_dec_len);
     else
-      sprintf(buff, "DOUBLE(%d,%d)", (int) max_length - (item->decimals + 1) + max_notzero_dec_len,
+      snprintf(buff, sizeof(buff), "DOUBLE(%d,%d)", (int) max_length - (item->decimals + 1) + max_notzero_dec_len,
 	      max_notzero_dec_len);
     answer->append(buff, (uint) strlen(buff));
   }
@@ -945,18 +945,18 @@ void field_longlong::get_opt_type(String *answer,
   char buff[MAX_FIELD_WIDTH];
 
   if (min_arg >= -128 && max_arg <= (min_arg >= 0 ? 255 : 127))
-    sprintf(buff, "TINYINT(%d)", (int) max_length);
+    snprintf(buff, sizeof(buff), "TINYINT(%d)", (int) max_length);
   else if (min_arg >= INT_MIN16 && max_arg <= (min_arg >= 0 ?
 					       UINT_MAX16 : INT_MAX16))
-    sprintf(buff, "SMALLINT(%d)", (int) max_length);
+    snprintf(buff, sizeof(buff), "SMALLINT(%d)", (int) max_length);
   else if (min_arg >= INT_MIN24 && max_arg <= (min_arg >= 0 ?
 					       UINT_MAX24 : INT_MAX24))
-    sprintf(buff, "MEDIUMINT(%d)", (int) max_length);
+    snprintf(buff, sizeof(buff), "MEDIUMINT(%d)", (int) max_length);
   else if (min_arg >= INT_MIN32 && max_arg <= (min_arg >= 0 ?
 					       UINT_MAX32 : INT_MAX32))
-    sprintf(buff, "INT(%d)", (int) max_length);
+    snprintf(buff, sizeof(buff), "INT(%d)", (int) max_length);
   else
-    sprintf(buff, "BIGINT(%d)", (int) max_length);
+    snprintf(buff, sizeof(buff), "BIGINT(%d)", (int) max_length);
   answer->append(buff, (uint) strlen(buff));
   if (min_arg >= 0)
     answer->append(STRING_WITH_LEN(" UNSIGNED"));
@@ -976,15 +976,15 @@ void field_ulonglong::get_opt_type(String *answer,
   char buff[MAX_FIELD_WIDTH];
 
   if (max_arg < 256)
-    sprintf(buff, "TINYINT(%d) UNSIGNED", (int) max_length);
+    snprintf(buff, sizeof(buff), "TINYINT(%d) UNSIGNED", (int) max_length);
    else if (max_arg <= ((2 * INT_MAX16) + 1))
-     sprintf(buff, "SMALLINT(%d) UNSIGNED", (int) max_length);
+     snprintf(buff, sizeof(buff), "SMALLINT(%d) UNSIGNED", (int) max_length);
   else if (max_arg <= ((2 * INT_MAX24) + 1))
-    sprintf(buff, "MEDIUMINT(%d) UNSIGNED", (int) max_length);
+    snprintf(buff, sizeof(buff), "MEDIUMINT(%d) UNSIGNED", (int) max_length);
   else if (max_arg < (((ulonglong) 1) << 32))
-    sprintf(buff, "INT(%d) UNSIGNED", (int) max_length);
+    snprintf(buff, sizeof(buff), "INT(%d) UNSIGNED", (int) max_length);
   else
-    sprintf(buff, "BIGINT(%d) UNSIGNED", (int) max_length);
+    snprintf(buff, sizeof(buff), "BIGINT(%d) UNSIGNED", (int) max_length);
   // if item is FIELD_ITEM, it _must_be_ Field_num in this class
   answer->append(buff, (uint) strlen(buff));
   if (item->type() == Item::FIELD_ITEM &&
@@ -1005,7 +1005,7 @@ void field_decimal::get_opt_type(String *answer,
   my_decimal_set_zero(&zero);
   my_bool is_unsigned= (my_decimal_cmp(&zero, &min_arg) >= 0);
 
-  length= sprintf(buff, "DECIMAL(%d, %d)",
+  length= snprintf(buff, sizeof(buff), "DECIMAL(%d, %d)",
                   (int) (max_length - (item->decimals ? 1 : 0)),
                   item->decimals);
   if (is_unsigned)
diff --git a/sql/sql_repl.cc b/sql/sql_repl.cc
index 7d1ddc08aaa..c52f0ab1ae9 100644
--- a/sql/sql_repl.cc
+++ b/sql/sql_repl.cc
@@ -4032,7 +4032,7 @@ bool mysql_show_binlog_events(THD* thd)
     binlog_size= s.st_size;
     if (lex_mi->pos > binlog_size)
     {
-      sprintf(errmsg_buf, "Invalid pos specified. Requested from pos:%llu is "
+      snprintf(errmsg_buf, sizeof(errmsg_buf), "Invalid pos specified. Requested from pos:%llu is "
               "greater than actual file size:%lu\n", lex_mi->pos,
               (ulong)s.st_size);
       errmsg= errmsg_buf;
diff --git a/storage/connect/bsonudf.cpp b/storage/connect/bsonudf.cpp
index 7d930d1f410..e93f40eb509 100644
--- a/storage/connect/bsonudf.cpp
+++ b/storage/connect/bsonudf.cpp
@@ -1144,7 +1144,7 @@ my_bool BJNX::LocateArray(PGLOBAL g, PBVAL jarp)
 
 	for (int i = 0; i < n && !Found; i++) {
 		Jp->N = m;
-		sprintf(s, "[%d]", i + B);
+		snprintf(s, sizeof(s), "[%d]", i + B);
 
 		if (Jp->WriteStr(s))
 			return true;
@@ -1438,7 +1438,7 @@ my_bool BJNX::AddPath(void)
 
 	for (int i = 0; i <= I; i++) {
 		if (Jpnp[i].Type == TYPE_JAR) {
-			sprintf(s, "[%d]", Jpnp[i].N + B);
+			snprintf(s, sizeof(s), "[%d]", Jpnp[i].N + B);
 
 			if (Jp->WriteStr(s))
 				return true;
diff --git a/storage/connect/global.h b/storage/connect/global.h
index eb3d4106477..bc1585eba41 100644
--- a/storage/connect/global.h
+++ b/storage/connect/global.h
@@ -14,6 +14,8 @@
 #include <time.h>                   /* time_t type declaration         */
 #include <setjmp.h>                 /* Long jump   declarations        */
 
+#define ROUNDUP_TO_8(num) (((num + 7) / 8) * 8)
+
 #if defined(_WIN32) && !defined(NOEX)
 #define DllExport  __declspec( dllexport )
 #else   // !_WIN32
diff --git a/storage/connect/jdbconn.cpp b/storage/connect/jdbconn.cpp
index 7af2b7e3a44..09786f28beb 100644
--- a/storage/connect/jdbconn.cpp
+++ b/storage/connect/jdbconn.cpp
@@ -451,8 +451,14 @@ PQRYRES JDBCSrcCols(PGLOBAL g, PCSZ src, PJPARM sjp)
 
 	if (strstr(src, "%s")) {
 		// Place holder for an eventual where clause
-		sqry = (char*)PlugSubAlloc(g, NULL, strlen(src) + 2);
-		sprintf(sqry, src, "1=1");			 // dummy where clause
+		size_t sqry_size = strlen(src) + 2;
+		sqry = (char*)PlugSubAlloc(g, NULL, sqry_size);
+		// Function PlugSubAlloc(...) recalculate string size
+		// while allocate memory - it rounds size up size to multiple of 8
+		// we need to know the real allocated size 
+		// to use it in sprintf(...)
+		const int sqry_real_allocated_size = ROUNDUP_TO_8(sqry_size);
+		snprintf(sqry, sqry_real_allocated_size, src, "1=1");			 // dummy where clause
 	} else
 		sqry = (char*)src;
 
diff --git a/storage/connect/json.cpp b/storage/connect/json.cpp
index 755480b1608..0786c3139e1 100644
--- a/storage/connect/json.cpp
+++ b/storage/connect/json.cpp
@@ -1023,13 +1023,13 @@ bool JDOC::SerializeValue(PJVAL jvp)
     case TYPE_DTM:
       return js->Escape(jvp->Strp);
     case TYPE_INTG:
-      sprintf(buf, "%d", jvp->N);
+      snprintf(buf, sizeof(buf), "%d", jvp->N);
       return js->WriteStr(buf);
     case TYPE_BINT:
-      sprintf(buf, "%lld", jvp->LLn);
+      snprintf(buf, sizeof(buf), "%lld", jvp->LLn);
       return js->WriteStr(buf);
     case TYPE_DBL:  // dfp to limit to the default number of decimals
-      sprintf(buf, "%.*f", MY_MIN(jvp->Nd, dfp), jvp->F);
+      snprintf(buf, sizeof(buf), "%.*f", MY_MIN(jvp->Nd, dfp), jvp->F);
       return js->WriteStr(buf);
     case TYPE_NULL:
       return js->WriteStr("null");
diff --git a/storage/connect/jsonudf.cpp b/storage/connect/jsonudf.cpp
index 2a209f67652..1b5ff9ae0c4 100644
--- a/storage/connect/jsonudf.cpp
+++ b/storage/connect/jsonudf.cpp
@@ -908,7 +908,7 @@ my_bool JSNX::LocateArray(PGLOBAL g, PJAR jarp)
 
 	for (int i = 0; i < jarp->size() && !Found; i++) {
 		Jp->N = m;
-		sprintf(s, "[%d]", i + B);
+		snprintf(s, sizeof(s), "[%d]", i + B);
 
 		if (Jp->WriteStr(s))
 			return true;
@@ -1189,7 +1189,7 @@ my_bool JSNX::AddPath(void) {
 
 	for (int i = 0; i <= I; i++) {
 		if (Jpnp[i].Type == TYPE_JAR) {
-			sprintf(s, "[%d]", Jpnp[i].N + B);
+			snprintf(s, sizeof(s), "[%d]", Jpnp[i].N + B);
 
 			if (Jp->WriteStr(s))
 				return true;
diff --git a/storage/connect/plugutil.cpp b/storage/connect/plugutil.cpp
index 8700bc992c4..be79d10eeb7 100644
--- a/storage/connect/plugutil.cpp
+++ b/storage/connect/plugutil.cpp
@@ -371,13 +371,13 @@ char *PlugReadMessage(PGLOBAL g, int mid, char *m)
   PlugSetPath(msgfile, NULL, buff, msg_path);
 
   if (!(mfile = fopen(msgfile, "rt"))) {
-    sprintf(stmsg, "Fail to open message file %s", msgfile);
+    snprintf(stmsg, sizeof(stmsg), "Fail to open message file %s", msgfile);
     goto err;
     } // endif mfile
 
   for (;;)
     if (!fgets(buff, 256, mfile)) {
-      sprintf(stmsg, "Cannot get message %d %s", mid, SVP(m));
+      snprintf(stmsg, sizeof(stmsg), "Cannot get message %d %s", mid, SVP(m));
       goto fin;
     } else
       if (atoi(buff) == mid)
@@ -386,7 +386,7 @@ char *PlugReadMessage(PGLOBAL g, int mid, char *m)
   if (sscanf(buff, " %*d %.31s \"%.255[^\"]", msgid, stmsg) < 2) {
     // Old message file
     if (!sscanf(buff, " %*d \"%.255[^\"]", stmsg)) {
-      sprintf(stmsg, "Bad message file for %d %s", mid, SVP(m));
+      snprintf(stmsg, sizeof(stmsg), "Bad message file for %d %s", mid, SVP(m));
       goto fin;
     } else
       m = NULL;
@@ -425,17 +425,18 @@ char *PlugGetMessage(PGLOBAL g, int mid)
 
   if (n == 0) {
     DWORD rc = GetLastError();
-    msg = (char*)PlugSubAlloc(g, NULL, 512);   // Extend buf allocation
-    n = sprintf(msg, "Message %d, rc=%d: ", mid, rc);
+    const int BUF_SIZE= 512;
+    msg = (char*)PlugSubAlloc(g, NULL, BUF_SIZE);   // Extend buf allocation
+    n = snprintf(msg, BUF_SIZE, "Message %d, rc=%d: ", mid, rc);
     FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
                   FORMAT_MESSAGE_IGNORE_INSERTS, NULL, rc, 0,
-                  (LPTSTR)(msg + n), 512 - n, NULL);
+                  (LPTSTR)(msg + n), BUF_SIZE - n, NULL);
     return msg;
     } // endif n
 
 #else  // ALL
   if (!GetRcString(mid, stmsg, 200))
-    sprintf(stmsg, "Message %d not found", mid);
+    snprintf(stmsg, sizeof(stmsg) "Message %d not found", mid);
 #endif // ALL
 
   if (g) {
@@ -564,7 +565,7 @@ void *PlugSubAlloc(PGLOBAL g, void *memp, size_t size)
     /*******************************************************************/
     memp = g->Sarea;
 
-  size = ((size + 7) / 8) * 8;       /* Round up size to multiple of 8 */
+  size = ROUNDUP_TO_8(size);      /* Round up size to multiple of 8 */
   pph = (PPOOLHEADER)memp;
 
   if (trace(16))
diff --git a/storage/connect/tabbson.cpp b/storage/connect/tabbson.cpp
index 95360487ac1..22d8648d7c0 100644
--- a/storage/connect/tabbson.cpp
+++ b/storage/connect/tabbson.cpp
@@ -477,7 +477,7 @@ bool BSONDISC::Find(PGLOBAL g, PBVAL jvp, PCSZ key, int j)
         n = sizeof(fmt) - (strlen(fmt) + 1);
 
         if (!tdp->Xcol || stricmp(tdp->Xcol, key)) {
-          sprintf(buf, "%d", k);
+          snprintf(buf, sizeof(buf), "%d", k);
 
           if (tdp->Uri) {
             strncat(strncat(fmt, sep, n), buf, n - strlen(sep));
@@ -798,7 +798,7 @@ void BCUTIL::SetJsonValue(PGLOBAL g, PVAL vp, PBVAL jvp)
 
           break;
         default:
-          sprintf(G->Message, "Unsupported column type %d", vp->GetType());
+          snprintf(G->Message, sizeof(G->Message), "Unsupported column type %d", vp->GetType());
           throw 888;
       } // endswitch Type
 
diff --git a/storage/connect/tabwmi.cpp b/storage/connect/tabwmi.cpp
index f90ff98ca35..935d21c59c9 100644
--- a/storage/connect/tabwmi.cpp
+++ b/storage/connect/tabwmi.cpp
@@ -810,7 +810,7 @@ void WMICOL::ReadColumn(PGLOBAL g)
           char       buf[24];
           int        rc = VariantTimeToSystemTime(Prop.date, &stm);
 
-          sprintf(buf, "%02d/%02d/%d %02d:%02d:%02d", 
+          snprintf(buf, sizeof(buf), "%02d/%02d/%d %02d:%02d:%02d", 
                        stm.wDay, stm.wMonth, stm.wYear,
                        stm.wHour, stm.wMinute, stm.wSecond);
           Value->SetValue_psz(buf);
diff --git a/storage/connect/valblk.cpp b/storage/connect/valblk.cpp
index 95327b5d30f..c3e42945d70 100644
--- a/storage/connect/valblk.cpp
+++ b/storage/connect/valblk.cpp
@@ -604,7 +604,7 @@ int TYPBLK<TYPE>::GetMaxLength(void)
   int i, n, m;
 
   for (i = n = 0; i < Nval; i++) {
-    m = sprintf(buf, Fmt, UnalignedRead(i));
+    m = snprintf(buf, sizeof(buf), Fmt, UnalignedRead(i));
     n = MY_MAX(n, m);
     } // endfor i
 
diff --git a/storage/federatedx/ha_federatedx.cc b/storage/federatedx/ha_federatedx.cc
index ddd6d932724..21c37907ee0 100644
--- a/storage/federatedx/ha_federatedx.cc
+++ b/storage/federatedx/ha_federatedx.cc
@@ -2626,7 +2626,7 @@ int ha_federatedx::index_read_idx_with_result_set(uchar *buf, uint index,
 
   if (io->query(sql_query.ptr(), sql_query.length()))
   {
-    sprintf(error_buffer, "error: %d '%s'",
+    snprintf(error_buffer, sizeof(error_buffer), "error: %d '%s'",
             io->error_code(), io->error_str());
     retval= ER_QUERY_ON_FOREIGN_DATA_SOURCE;
     goto error;
@@ -3352,7 +3352,7 @@ static int test_connection(MYSQL_THD thd, federatedx_io *io,
 
   if ((retval= io->query(str.ptr(), str.length())))
   {
-    sprintf(buffer, "database: '%s'  username: '%s'  hostname: '%s'",
+    snprintf(buffer, sizeof(buffer), "database: '%s'  username: '%s'  hostname: '%s'",
             share->database, share->username, share->hostname);
     DBUG_PRINT("info", ("error-code: %d", io->error_code()));
     my_error(ER_CANT_CREATE_FEDERATED_TABLE, MYF(0), buffer);