Bug#32167 another privilege bypass with DATA/INDEX DIRECORY(ver 4.1,5.0)

added new function test_if_data_home_dir() which checks that
path does not contain mysql data home directory.
Using of mysql data home directory in
DATA DIRECTORY & INDEX DIRECTORY is disallowed.

mysql-test/r/symlink.result

@@ -91,23 +91,15 @@ t1	CREATE TABLE `t1` (
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
 CREATE TABLE t1(a INT)
-DATA DIRECTORY='TEST_DIR/master-data/mysql'
-INDEX DIRECTORY='TEST_DIR/master-data/mysql';
-RENAME TABLE t1 TO user;
-ERROR HY000: Can't create/write to file 'TEST_DIR/master-data/mysql/user.MYI' (Errcode: 17)
-DROP TABLE t1;
-show create table t1;
-Table	Create Table
-t1	CREATE TABLE `t1` (
-  `i` int(11) default NULL
-) ENGINE=MyISAM DEFAULT CHARSET=latin1
-drop table t1;
-show create table t1;
-Table	Create Table
-t1	CREATE TABLE `t1` (
-  `i` int(11) default NULL
-) ENGINE=MyISAM DEFAULT CHARSET=latin1
-drop table t1;
+DATA DIRECTORY='TEST_DIR/tmp'
+INDEX DIRECTORY='TEST_DIR/tmp';
+ERROR HY000: Can't create/write to file 'TEST_DIR/tmp/t1.MYI' (Errcode: 17)
+CREATE TABLE t2(a INT)
+DATA DIRECTORY='TEST_DIR/tmp'
+INDEX DIRECTORY='TEST_DIR/tmp';
+RENAME TABLE t2 TO t1;
+ERROR HY000: Can't create/write to file 'TEST_DIR/tmp/t1.MYI' (Errcode: 17)
+DROP TABLE t2;
 show create table t1;
 Table	Create Table
 t1	CREATE TEMPORARY TABLE `t1` (
@@ -144,4 +136,16 @@ t1	CREATE TABLE `t1` (
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1 DATA DIRECTORY='MYSQLTEST_VARDIR/tmp/'
 drop table t1;
 deallocate prepare stmt;
+CREATE TABLE t1(a INT)
+DATA DIRECTORY='TEST_DIR/var/master-data/test';
+ERROR HY000: Incorrect arguments to DATA DIRECORY
+CREATE TABLE t1(a INT)
+DATA DIRECTORY='/home/gluh/MySQL/Merge/4.1-opt/mysql-test/var/master-data/';
+ERROR HY000: Incorrect arguments to DATA DIRECORY
+CREATE TABLE t1(a INT)
+INDEX DIRECTORY='/home/gluh/MySQL/Merge/4.1-opt/mysql-test/var/master-data';
+ERROR HY000: Incorrect arguments to INDEX DIRECORY
+CREATE TABLE t1(a INT)
+INDEX DIRECTORY='/home/gluh/MySQL/Merge/4.1-opt/mysql-test/var/master-data_var';
+ERROR HY000: Can't create/write to file '/home/gluh/MySQL/Merge/4.1-opt/mysql-test/var/master-data_var/t1.MYI' (Errcode: 2)
 End of 4.1 tests

mysql-test/t/symlink.test

@@ -121,29 +121,22 @@ drop table t1;
 #
 # BUG#32111 - Security Breach via DATA/INDEX DIRECORY and RENAME TABLE
 #
+--write_file $MYSQLTEST_VARDIR/tmp/t1.MYI
+EOF
 --replace_result $MYSQLTEST_VARDIR TEST_DIR
+--error 1
 eval CREATE TABLE t1(a INT)
-DATA DIRECTORY='$MYSQLTEST_VARDIR/master-data/mysql'
-INDEX DIRECTORY='$MYSQLTEST_VARDIR/master-data/mysql';
+DATA DIRECTORY='$MYSQLTEST_VARDIR/tmp'
+INDEX DIRECTORY='$MYSQLTEST_VARDIR/tmp';
+--replace_result $MYSQLTEST_VARDIR TEST_DIR
+eval CREATE TABLE t2(a INT)
+DATA DIRECTORY='$MYSQLTEST_VARDIR/tmp'
+INDEX DIRECTORY='$MYSQLTEST_VARDIR/tmp';
 --replace_result $MYSQLTEST_VARDIR TEST_DIR
 --error 1
-RENAME TABLE t1 TO user;
-DROP TABLE t1;
-
-#
-# Test specifying DATA DIRECTORY that is the same as what would normally
-# have been chosen. (Bug #8707)
-#
-disable_query_log;
-eval create table t1 (i int) data directory = "$MYSQL_TEST_DIR/var/master-data/test/";
-enable_query_log;
-show create table t1;
-drop table t1;
-disable_query_log;
-eval create table t1 (i int) index directory = "$MYSQL_TEST_DIR/var/master-data/test/";
-enable_query_log;
-show create table t1;
-drop table t1;
+RENAME TABLE t2 TO t1;
+DROP TABLE t2;
+--remove_file $MYSQLTEST_VARDIR/tmp/t1.MYI
 
 #
 # Bug#8706 - temporary table with data directory option fails
@@ -201,4 +194,21 @@ show create table t1;
 drop table t1;
 deallocate prepare stmt;
 
+#
+# Bug#32167 another privilege bypass with DATA/INDEX DIRECORY
+#
+--replace_result $MYSQL_TEST_DIR TEST_DIR
+--error 1210
+eval CREATE TABLE t1(a INT)
+DATA DIRECTORY='$MYSQL_TEST_DIR/var/master-data/test';
+--error 1210
+eval CREATE TABLE t1(a INT)
+DATA DIRECTORY='$MYSQL_TEST_DIR/var/master-data/';
+--error 1210
+eval CREATE TABLE t1(a INT)
+INDEX DIRECTORY='$MYSQL_TEST_DIR/var/master-data';
+--error 1
+eval CREATE TABLE t1(a INT)
+INDEX DIRECTORY='$MYSQL_TEST_DIR/var/master-data_var';
+
 --echo End of 4.1 tests

sql/mysql_priv.h

@@ -890,6 +890,7 @@ void my_dbopt_free(void);
 extern time_t start_time;
 extern char *mysql_data_home,server_version[SERVER_VERSION_LENGTH],
 	    mysql_real_data_home[], *opt_mysql_tmpdir, mysql_charsets_dir[],
+	    mysql_unpacked_real_data_home[],
             def_ft_boolean_syntax[sizeof(ft_boolean_syntax)];
 #define mysql_tmpdir (my_tmpdir(&mysql_tmpdir_list))
 extern MY_TMPDIR mysql_tmpdir_list;

sql/mysqld.cc

@@ -390,6 +390,7 @@ const char *opt_date_time_formats[3];
 char compiled_default_collation_name[]= MYSQL_DEFAULT_COLLATION_NAME;
 char *language_ptr, *default_collation_name, *default_character_set_name;
 char mysql_data_home_buff[2], *mysql_data_home=mysql_real_data_home;
+char mysql_unpacked_real_data_home[FN_REFLEN];
 struct passwd *user_info;
 char server_version[SERVER_VERSION_LENGTH];
 char *mysqld_unix_port, *opt_mysql_tmpdir;
@@ -6896,6 +6897,9 @@ static void fix_paths(void)
     pos[1]= 0;
   }
   convert_dirname(mysql_real_data_home,mysql_real_data_home,NullS);
+  (void) fn_format(buff, mysql_real_data_home, "", "",
+                   (MY_RETURN_REAL_PATH|MY_RESOLVE_SYMLINKS));
+  (void) unpack_dirname(mysql_unpacked_real_data_home, buff);
   convert_dirname(language,language,NullS);
   (void) my_load_path(mysql_home,mysql_home,""); // Resolve current dir
   (void) my_load_path(mysql_real_data_home,mysql_real_data_home,mysql_home);

sql/sql_parse.cc

@@ -66,6 +66,7 @@ static bool append_file_to_dir(THD *thd, const char **filename_ptr,
              
 static TABLE_LIST* get_table_by_alias(TABLE_LIST* tl, const char* db,
   const char* alias);
+static bool test_if_data_home_dir(const char *dir);
 
 const char *any_db="*any*";	// Special symbol for check_access
 
@@ -2531,6 +2532,20 @@ mysql_execute_command(THD *thd)
                    "INDEX DIRECTORY option ignored");
     create_info.data_file_name= create_info.index_file_name= NULL;
 #else
+
+    if (test_if_data_home_dir(lex->create_info.data_file_name))
+    {
+      my_error(ER_WRONG_ARGUMENTS,MYF(0),"DATA DIRECORY");
+      res= -1;
+      break;
+    }
+    if (test_if_data_home_dir(lex->create_info.index_file_name))
+    {
+      my_error(ER_WRONG_ARGUMENTS,MYF(0),"INDEX DIRECORY");
+      res= -1;
+      break;
+    }
+
     /* Fix names if symlinked tables */
     if (append_file_to_dir(thd, &create_info.data_file_name,
 			   create_table->real_name) ||
@@ -5920,3 +5935,47 @@ Item *negate_expression(THD *thd, Item *expr)
     return negated;
   return new Item_func_not(expr);
 }
+
+
+/*
+  Check if path does not contain mysql data home directory
+
+  SYNOPSIS
+    test_if_data_home_dir()
+    dir                     directory
+    conv_home_dir           converted data home directory
+    home_dir_len            converted data home directory length
+
+  RETURN VALUES
+    0	ok
+    1	error  
+*/
+
+static bool test_if_data_home_dir(const char *dir)
+{
+  char path[FN_REFLEN], conv_path[FN_REFLEN];
+  uint dir_len, home_dir_len= strlen(mysql_unpacked_real_data_home);
+  DBUG_ENTER("test_if_data_home_dir");
+
+  if (!dir)
+    DBUG_RETURN(0);
+
+  (void) fn_format(path, dir, "", "",
+                   (MY_RETURN_REAL_PATH|MY_RESOLVE_SYMLINKS));
+  dir_len= unpack_dirname(conv_path, dir);
+
+  if (home_dir_len <= dir_len)
+  {
+    if (lower_case_file_system)
+    {
+      if (!my_strnncoll(default_charset_info, (const uchar*) conv_path,
+                        home_dir_len,
+                        (const uchar*) mysql_unpacked_real_data_home,
+                        home_dir_len))
+        DBUG_RETURN(1);
+    }
+    else if (!memcmp(conv_path, mysql_unpacked_real_data_home, home_dir_len))
+      DBUG_RETURN(1);
+  }
+  DBUG_RETURN(0);
+}