MDEV-15465 Server crash or ASAN heap-use-after-free in Item_func_match::cleanup upon using FT search with partitioning.

Partition engine FT keys are implemented in such a way that
the FT function's cleanup() methods use table's internals.
So calling them after close_thread_tables is unsafe.

mysql-test/main/partition_sync.result

@@ -61,3 +61,28 @@ connection default;
 disconnect con2;
 disconnect con3;
 DROP TABLE tbl_with_partitions;
+#
+# MDEV-15465 Server crash or ASAN heap-use-after-free in Item_func_match::cleanup
+#            upon using FT search with partitioning.
+#
+connect  con1,localhost,root,,test;
+CREATE OR REPLACE TABLE t1 (c CHAR(8)) ENGINE=MyISAM PARTITION BY KEY(c);
+connection default;
+set debug_sync= 'execute_command_after_close_tables SIGNAL opened WAIT_FOR go';
+DELETE FROM t1 WHERE MATCH(c) AGAINST ('foo' IN BOOLEAN MODE);
+connection con1;
+set debug_sync= 'now WAIT_FOR opened';
+FLUSH TABLES;
+set debug_sync= 'now SIGNAL go';
+connection default;
+set debug_sync= 'execute_command_after_close_tables SIGNAL opened WAIT_FOR go';
+SELECT * FROM t1 WHERE MATCH(c) AGAINST ('foo' IN BOOLEAN MODE);
+connection con1;
+set debug_sync= 'now WAIT_FOR opened';
+FLUSH TABLES;
+set debug_sync= 'now SIGNAL go';
+disconnect con1;
+connection default;
+c
+DROP TABLE t1;
+set debug_sync= 'RESET';

mysql-test/main/partition_sync.test

@@ -77,6 +77,42 @@ disconnect con2;
 disconnect con3;
 DROP TABLE tbl_with_partitions;
 
+--echo #
+--echo # MDEV-15465 Server crash or ASAN heap-use-after-free in Item_func_match::cleanup
+--echo #            upon using FT search with partitioning.
+--echo #
+
+--connect (con1,localhost,root,,test)
+CREATE OR REPLACE TABLE t1 (c CHAR(8)) ENGINE=MyISAM PARTITION BY KEY(c);
+
+--connection default
+set debug_sync= 'execute_command_after_close_tables SIGNAL opened WAIT_FOR go';
+--send
+DELETE FROM t1 WHERE MATCH(c) AGAINST ('foo' IN BOOLEAN MODE);
+
+--connection con1
+set debug_sync= 'now WAIT_FOR opened';
+FLUSH TABLES;
+set debug_sync= 'now SIGNAL go';
+
+--connection default
+--reap
+set debug_sync= 'execute_command_after_close_tables SIGNAL opened WAIT_FOR go';
+--send
+SELECT * FROM t1 WHERE MATCH(c) AGAINST ('foo' IN BOOLEAN MODE);
+
+--connection con1
+set debug_sync= 'now WAIT_FOR opened';
+FLUSH TABLES;
+set debug_sync= 'now SIGNAL go';
+
+# Cleanup
+--disconnect con1
+--connection default
+--reap
+DROP TABLE t1;
+set debug_sync= 'RESET';
+
 
 # Check that all connections opened by test cases in this file are really
 # gone so execution of other tests won't be affected by their presence.

sql/sql_base.cc

@@ -8639,6 +8639,19 @@ int setup_ftfuncs(SELECT_LEX *select_lex)
 }
 
 
+void cleanup_ftfuncs(SELECT_LEX *select_lex)
+{
+  List_iterator<Item_func_match> li(*(select_lex->ftfunc_list)),
+                                 lj(*(select_lex->ftfunc_list));
+  Item_func_match *ftf;
+
+  while ((ftf=li++))
+  {
+    ftf->cleanup();
+  }
+}
+
+
 int init_ftfuncs(THD *thd, SELECT_LEX *select_lex, bool no_order)
 {
   if (select_lex->ftfunc_list->elements)

sql/sql_base.h

@@ -216,6 +216,7 @@ int setup_conds(THD *thd, TABLE_LIST *tables, List<TABLE_LIST> &leaves,
 		COND **conds);
 void wrap_ident(THD *thd, Item **conds);
 int setup_ftfuncs(SELECT_LEX* select);
+void cleanup_ftfuncs(SELECT_LEX *select_lex);
 int init_ftfuncs(THD *thd, SELECT_LEX* select, bool no_order);
 bool lock_table_names(THD *thd, const DDL_options_st &options,
                       TABLE_LIST *table_list,

sql/sql_union.cc

@@ -1916,6 +1916,7 @@ bool st_select_lex::cleanup()
 
   cleanup_order(order_list.first);
   cleanup_order(group_list.first);
+  cleanup_ftfuncs(this);
 
   if (join)
   {