Bug#21977380 - POSSIBLE BUFFER OVERFLOW ISSUES

DESCRIPTION
===========
Buffer overflow is reported in a lot of code sections
spanning across server, client programs, Regex libraries
etc. If not handled appropriately, they can cause abnormal
behaviour.

ANALYSIS
========
The reported casea are the ones which are likely to result
in SEGFAULT, MEMORY LEAK etc.

FIX
===
- sprintf() has been replaced by my_snprintf() to avoid
buffer overflow.
- my_free() is done after checking if the pointer isn't
  NULL already and setting it to NULL thereafter at few
  places.
- Buffer is ensured to be large enough to hold the data.
- 'unsigned int' (aka 'uint') is replaced with 'size_t'
to avoid wraparound.
- Memory is freed (if not done so) after its alloced and
used.
- Inserted assert() for size check in InnoDb memcached
code (from 5.6 onwards)
- Other minor changes

(cherry picked from commit 3487e20959c940cbd24429afa795ebfc8a01e94f)

Author: Shishir Jaiswal

client/mysqlcheck.c

@@ -213,13 +213,13 @@ static int process_selected_tables(char *db, char **table_names, int tables);
 static int process_all_tables_in_db(char *database);
 static int process_one_db(char *database);
 static int use_db(char *database);
-static int handle_request_for_tables(char *tables, uint length);
+static int handle_request_for_tables(char *tables, size_t length);
 static int dbConnect(char *host, char *user,char *passwd);
 static void dbDisconnect(char *host);
 static void DBerror(MYSQL *mysql, const char *when);
 static void safe_exit(int error);
 static void print_result();
-static uint fixed_name_length(const char *name);
+static size_t fixed_name_length(const char *name);
 static char *fix_table_name(char *dest, char *src);
 int what_to_do = 0;
 
@@ -486,7 +486,7 @@ static int process_selected_tables(char *db, char **table_names, int tables)
       *end++= ',';
     }
     *--end = 0;
-    handle_request_for_tables(table_names_comma_sep + 1, (uint) (tot_length - 1));
+    handle_request_for_tables(table_names_comma_sep + 1, tot_length - 1);
     my_free(table_names_comma_sep);
   }
   else
@@ -496,10 +496,10 @@ static int process_selected_tables(char *db, char **table_names, int tables)
 } /* process_selected_tables */
 
 
-static uint fixed_name_length(const char *name)
+static size_t fixed_name_length(const char *name)
 {
   const char *p;
-  uint extra_length= 2;  /* count the first/last backticks */
+  size_t extra_length= 2;  /* count the first/last backticks */
 
   for (p= name; *p; p++)
   {
@@ -508,7 +508,7 @@ static uint fixed_name_length(const char *name)
     else if (*p == '.')
       extra_length+= 2;
   }
-  return (uint) ((p - name) + extra_length);
+  return (size_t) ((p - name) + extra_length);
 }
 
 
@@ -564,7 +564,7 @@ static int process_all_tables_in_db(char *database)
      */
 
     char *tables, *end;
-    uint tot_length = 0;
+    size_t tot_length = 0;
 
     while ((row = mysql_fetch_row(res)))
       tot_length+= fixed_name_length(row[0]) + 2;
@@ -622,7 +622,9 @@ static int fix_table_storage_name(const char *name)
   int rc= 0;
   if (strncmp(name, "#mysql50#", 9))
     return 1;
-  sprintf(qbuf, "RENAME TABLE `%s` TO `%s`", name, name + 9);
+  my_snprintf(qbuf, sizeof(qbuf), "RENAME TABLE `%s` TO `%s`",
+              name, name + 9);
+
   rc= run_query(qbuf);
   if (verbose)
     printf("%-50s %s\n", name, rc ? "FAILED" : "OK");
@@ -635,7 +637,8 @@ static int fix_database_storage_name(const char *name)
   int rc= 0;
   if (strncmp(name, "#mysql50#", 9))
     return 1;
-  sprintf(qbuf, "ALTER DATABASE `%s` UPGRADE DATA DIRECTORY NAME", name);
+  my_snprintf(qbuf, sizeof(qbuf), "ALTER DATABASE `%s` UPGRADE DATA DIRECTORY "
+              "NAME", name);
   rc= run_query(qbuf);
   if (verbose)
     printf("%-50s %s\n", name, rc ? "FAILED" : "OK");
@@ -653,7 +656,7 @@ static int rebuild_table(char *name)
   ptr= strmov(query, "ALTER TABLE ");
   ptr= fix_table_name(ptr, name);
   ptr= strxmov(ptr, " FORCE", NullS);
-  if (mysql_real_query(sock, query, (uint)(ptr - query)))
+  if (mysql_real_query(sock, query, (ulong)(ptr - query)))
   {
     fprintf(stderr, "Failed to %s\n", query);
     fprintf(stderr, "Error: %s\n", mysql_error(sock));
@@ -702,10 +705,10 @@ static int disable_binlog()
   return run_query(stmt);
 }
 
-static int handle_request_for_tables(char *tables, uint length)
+static int handle_request_for_tables(char *tables, size_t length)
 {
   char *query, *end, options[100], message[100];
-  uint query_length= 0;
+  size_t query_length= 0, query_size= sizeof(char)*(length+110);
   const char *op = 0;
 
   options[0] = 0;
@@ -736,10 +739,14 @@ static int handle_request_for_tables(char *tables, uint length)
     return fix_table_storage_name(tables);
   }
 
-  if (!(query =(char *) my_malloc((sizeof(char)*(length+110)), MYF(MY_WME))))
+  if (!(query =(char *) my_malloc(query_size, MYF(MY_WME))))
+  {
     return 1;
+  }
   if (opt_all_in_1)
   {
+    DBUG_ASSERT(strlen(op)+strlen(tables)+strlen(options)+8+1 <= query_size);
+
     /* No backticks here as we added them before */
     query_length= sprintf(query, "%s TABLE %s %s", op, tables, options);
   }
@@ -750,7 +757,7 @@ static int handle_request_for_tables(char *tables, uint length)
     ptr= strmov(strmov(query, op), " TABLE ");
     ptr= fix_table_name(ptr, tables);
     ptr= strxmov(ptr, " ", options, NullS);
-    query_length= (uint) (ptr - query);
+    query_length= (size_t) (ptr - query);
   }
   if (mysql_real_query(sock, query, query_length))
   {
@@ -834,7 +841,10 @@ static void print_result()
               prev_alter[0]= 0;
             }
             else
-              strcpy(prev_alter, alter_txt);
+            {
+              strncpy(prev_alter, alter_txt, MAX_ALTER_STR_SIZE-1);
+              prev_alter[MAX_ALTER_STR_SIZE-1]= 0;
+            }
           }
         }
       }
@@ -978,7 +988,7 @@ int main(int argc, char **argv)
     process_databases(argv);
   if (opt_auto_repair)
   {
-    uint i;
+    size_t i;
 
     if (!opt_silent && (tables4repair.elements || tables4rebuild.elements))
       puts("\nRepairing tables");

client/mysqldump.c

@@ -86,7 +86,7 @@
 
 static void add_load_option(DYNAMIC_STRING *str, const char *option,
                              const char *option_value);
-static ulong find_set(TYPELIB *lib, const char *x, uint length,
+static ulong find_set(TYPELIB *lib, const char *x, size_t length,
                       char **err_pos, uint *err_len);
 static char *alloc_query_str(ulong size);
 
@@ -852,7 +852,7 @@ get_one_option(int optid, const struct my_option *opt __attribute__((unused)),
       opt_set_charset= 0;
       opt_compatible_mode_str= argument;
       opt_compatible_mode= find_set(&compatible_mode_typelib,
-                                    argument, (uint) strlen(argument),
+                                    argument, strlen(argument),
                                     &err_ptr, &err_len);
       if (err_len)
       {
@@ -862,7 +862,7 @@ get_one_option(int optid, const struct my_option *opt __attribute__((unused)),
       }
 #if !defined(DBUG_OFF)
       {
-        uint size_for_sql_mode= 0;
+        size_t size_for_sql_mode= 0;
         const char **ptr;
         for (ptr= compatible_mode_names; *ptr; ptr++)
           size_for_sql_mode+= strlen(*ptr);
@@ -1138,8 +1138,8 @@ static int fetch_db_collation(const char *db_name,
       break;
     }
 
-    strncpy(db_cl_name, db_cl_row[0], db_cl_size);
-    db_cl_name[db_cl_size - 1]= 0; /* just in case. */
+    strncpy(db_cl_name, db_cl_row[0], db_cl_size-1);
+    db_cl_name[db_cl_size - 1]= 0;
 
   } while (FALSE);
 
@@ -1150,7 +1150,7 @@ static int fetch_db_collation(const char *db_name,
 
 
 static char *my_case_str(const char *str,
-                         uint str_len,
+                         size_t str_len,
                          const char *token,
                          uint token_len)
 {
@@ -1366,7 +1366,7 @@ static int switch_character_set_results(MYSQL *mysql, const char *cs_name)
 */
 
 static char *cover_definer_clause(const char *stmt_str,
-                                  uint stmt_length,
+                                  size_t stmt_length,
                                   const char *definer_version_str,
                                   uint definer_version_length,
                                   const char *stmt_version_str,
@@ -1548,14 +1548,14 @@ static void dbDisconnect(char *host)
 } /* dbDisconnect */
 
 
-static void unescape(FILE *file,char *pos,uint length)
+static void unescape(FILE *file,char *pos, size_t length)
 {
   char *tmp;
   DBUG_ENTER("unescape");
   if (!(tmp=(char*) my_malloc(length*2+1, MYF(MY_WME))))
     die(EX_MYSQLERR, "Couldn't allocate memory");
 
-  mysql_real_escape_string(&mysql_connection, tmp, pos, length);
+  mysql_real_escape_string(&mysql_connection, tmp, pos, (ulong)length);
   fputc('\'', file);
   fputs(tmp, file);
   fputc('\'', file);
@@ -1669,7 +1669,7 @@ static char *quote_for_like(const char *name, char *buff)
     Quote '<' '>' '&' '\"' chars and print a string to the xml_file.
 */
 
-static void print_quoted_xml(FILE *xml_file, const char *str, ulong len,
+static void print_quoted_xml(FILE *xml_file, const char *str, size_t len,
                              my_bool is_attribute_name)
 {
   const char *end;
@@ -1928,7 +1928,7 @@ static void print_xml_row(FILE *xml_file, const char *row_name,
     squeezed to a single hyphen.
 */
 
-static void print_xml_comment(FILE *xml_file, ulong len,
+static void print_xml_comment(FILE *xml_file, size_t len,
                               const char *comment_string)
 {
   const char* end;
@@ -2045,7 +2045,7 @@ static uint dump_events_for_db(char *db)
   DBUG_ENTER("dump_events_for_db");
   DBUG_PRINT("enter", ("db: '%s'", db));
 
-  mysql_real_escape_string(mysql, db_name_buff, db, strlen(db));
+  mysql_real_escape_string(mysql, db_name_buff, db, (ulong)strlen(db));
 
   /* nice comments */
   print_comment(sql_file, 0,
@@ -2164,6 +2164,11 @@ static uint dump_events_for_db(char *db)
                   (const char *) (query_str != NULL ? query_str : row[3]),
                   (const char *) delimiter);
 
+          if(query_str)
+          {
+            my_free(query_str);
+            query_str= NULL;
+          }
           restore_time_zone(sql_file, delimiter);
           restore_sql_mode(sql_file, delimiter);
 
@@ -2257,7 +2262,7 @@ static uint dump_routines_for_db(char *db)
   DBUG_ENTER("dump_routines_for_db");
   DBUG_PRINT("enter", ("db: '%s'", db));
 
-  mysql_real_escape_string(mysql, db_name_buff, db, strlen(db));
+  mysql_real_escape_string(mysql, db_name_buff, db, (ulong)strlen(db));
 
   /* nice comments */
   print_comment(sql_file, 0,
@@ -2311,9 +2316,9 @@ static uint dump_routines_for_db(char *db)
             if the user has EXECUTE privilege he see routine names, but NOT the
             routine body of other routines that are not the creator of!
           */
-          DBUG_PRINT("info",("length of body for %s row[2] '%s' is %d",
+          DBUG_PRINT("info",("length of body for %s row[2] '%s' is %zu",
                              routine_name, row[2] ? row[2] : "(null)",
-                             row[2] ? (int) strlen(row[2]) : 0));
+                             row[2] ? strlen(row[2]) : 0));
           if (row[2] == NULL)
           {
             print_comment(sql_file, 1, "\n-- insufficient privileges to %s\n",
@@ -3873,7 +3878,7 @@ static int dump_tablespaces_for_tables(char *db, char **table_names, int tables)
   int i;
   char name_buff[NAME_LEN*2+3];
 
-  mysql_real_escape_string(mysql, name_buff, db, strlen(db));
+  mysql_real_escape_string(mysql, name_buff, db, (ulong)strlen(db));
 
   init_dynamic_string_checked(&where, " AND TABLESPACE_NAME IN ("
                       "SELECT DISTINCT TABLESPACE_NAME FROM"
@@ -3886,7 +3891,7 @@ static int dump_tablespaces_for_tables(char *db, char **table_names, int tables)
   for (i=0 ; i<tables ; i++)
   {
     mysql_real_escape_string(mysql, name_buff,
-                             table_names[i], strlen(table_names[i]));
+                             table_names[i], (ulong)strlen(table_names[i]));
 
     dynstr_append_checked(&where, "'");
     dynstr_append_checked(&where, name_buff);
@@ -3917,7 +3922,7 @@ static int dump_tablespaces_for_databases(char** databases)
   {
     char db_name_buff[NAME_LEN*2+3];
     mysql_real_escape_string(mysql, db_name_buff,
-                             databases[i], strlen(databases[i]));
+                             databases[i], (ulong)strlen(databases[i]));
     dynstr_append_checked(&where, "'");
     dynstr_append_checked(&where, db_name_buff);
     dynstr_append_checked(&where, "',");
@@ -4927,7 +4932,7 @@ static int start_transaction(MYSQL *mysql_con)
 }
 
 
-static ulong find_set(TYPELIB *lib, const char *x, uint length,
+static ulong find_set(TYPELIB *lib, const char *x, size_t length,
                       char **err_pos, uint *err_len)
 {
   const char *end= x + length;
@@ -4985,7 +4990,7 @@ static void print_value(FILE *file, MYSQL_RES  *result, MYSQL_ROW row,
         fputc(' ',file);
         fputs(prefix, file);
         if (string_value)
-          unescape(file,row[0],(uint) strlen(row[0]));
+          unescape(file,row[0], strlen(row[0]));
         else
           fputs(row[0], file);
         check_io(file);
@@ -5238,8 +5243,8 @@ static my_bool get_view_structure(char *table, char* db)
   verbose_msg("-- Retrieving view structure for table %s...\n", table);
 
 #ifdef NOT_REALLY_USED_YET
-  sprintf(insert_pat, "SET SQL_QUOTE_SHOW_CREATE=%d",
-          (opt_quoted || opt_keywords));
+  dynstr_append_checked(&insert_pat, "SET SQL_QUOTE_SHOW_CREATE=");
+  dynstr_append_checked(&insert_pat, (opt_quoted || opt_keywords)? "1":"0");
 #endif
 
   result_table=     quote_name(table, table_buff, 1);