Bug #17139: Partitions: unprivileged user can effectively drop table

Now the DROP privilege is also required on a table in order to be able
to drop a partition from the table using ALTER TABLE.

mysql-test/r/partition_grant.result

+drop schema if exists mysqltest_1;
+create schema mysqltest_1;
+use mysqltest_1;
+create table t1 (a int) partition by list (a) (partition p1 values in (1), partition p2 values in (2), partition p3 values in (3));
+insert into t1 values (1),(2);
+grant select,alter on mysqltest_1.* to mysqltest_1@localhost;
+show grants for current_user;
+Grants for mysqltest_1@localhost
+GRANT USAGE ON *.* TO 'mysqltest_1'@'localhost'
+GRANT SELECT, ALTER ON `mysqltest_1`.* TO 'mysqltest_1'@'localhost'
+alter table t1 add b int;
+alter table t1 drop partition p2;
+ERROR 42000: DROP command denied to user 'mysqltest_1'@'localhost' for table 't1'
+grant drop on mysqltest_1.* to mysqltest_1@localhost;
+alter table t1 drop partition p2;
+revoke alter on mysqltest_1.* from mysqltest_1@localhost;
+alter table t1 drop partition p3;
+ERROR 42000: ALTER command denied to user 'mysqltest_1'@'localhost' for table 't1'
+revoke select,alter,drop on mysqltest_1.* from mysqltest_1@localhost;
+drop user mysqltest_1@localhost;
+drop table t1;
+drop schema mysqltest_1;
+End of 5.1 tests

mysql-test/t/partition_grant.test

+-- source include/have_partition.inc
+# Grant tests not performed with embedded server
+-- source include/not_embedded.inc
+
+--disable_warnings
+drop schema if exists mysqltest_1;
+--enable_warnings
+
+
+#
+# Bug #17139: ALTER TABLE ... DROP PARTITION should require DROP privilege
+#
+
+create schema mysqltest_1;
+use mysqltest_1;
+
+create table t1 (a int) partition by list (a) (partition p1 values in (1), partition p2 values in (2), partition p3 values in (3));
+insert into t1 values (1),(2);
+
+grant select,alter on mysqltest_1.* to mysqltest_1@localhost;
+
+connect (conn1,localhost,mysqltest_1,,mysqltest_1);
+show grants for current_user;
+alter table t1 add b int;
+--error ER_TABLEACCESS_DENIED_ERROR
+alter table t1 drop partition p2;
+disconnect conn1;
+
+connection default;
+grant drop on mysqltest_1.* to mysqltest_1@localhost;
+
+connect (conn2,localhost,mysqltest_1,,mysqltest_1);
+alter table t1 drop partition p2;
+disconnect conn2;
+
+connection default;
+revoke alter on mysqltest_1.* from mysqltest_1@localhost;
+
+connect (conn3,localhost,mysqltest_1,,mysqltest_1);
+--error ER_TABLEACCESS_DENIED_ERROR
+alter table t1 drop partition p3;
+disconnect conn3;
+
+connection default;
+
+revoke select,alter,drop on mysqltest_1.* from mysqltest_1@localhost;
+drop user mysqltest_1@localhost;
+drop table t1;
+drop schema mysqltest_1;
+
+--echo End of 5.1 tests

sql/sql_parse.cc

@@ -2975,6 +2975,11 @@ mysql_execute_command(THD *thd)
 #else
     {
       ulong priv=0;
+      ulong priv_needed= ALTER_ACL;
+      /* We also require DROP priv for ALTER TABLE ... DROP PARTITION */
+      if (lex->alter_info.flags & ALTER_DROP_PARTITION)
+        priv_needed|= DROP_ACL;
+
       if (lex->name && (!lex->name[0] || strlen(lex->name) > NAME_LEN))
       {
 	my_error(ER_WRONG_TABLE_NAME, MYF(0), lex->name);
@@ -2999,7 +3004,7 @@ mysql_execute_command(THD *thd)
         else
           select_lex->db= first_table->db;
       }
-      if (check_access(thd, ALTER_ACL, first_table->db,
+      if (check_access(thd, priv_needed, first_table->db,
 		       &first_table->grant.privilege, 0, 0,
                        test(first_table->schema_table)) ||
 	  check_access(thd,INSERT_ACL | CREATE_ACL,select_lex->db,&priv,0,0,
@@ -3010,7 +3015,7 @@ mysql_execute_command(THD *thd)
 	goto error;				/* purecov: inspected */
       if (grant_option)
       {
-	if (check_grant(thd, ALTER_ACL, all_tables, 0, UINT_MAX, 0))
+	if (check_grant(thd, priv_needed, all_tables, 0, UINT_MAX, 0))
 	  goto error;
 	if (lex->name && !test_all_bits(priv,INSERT_ACL | CREATE_ACL))
 	{					// Rename of table