maria-developers team mailing list archive

[Alexander Barkov <bar@xxxxxxxxxxx>]

Hello Alexey,

can you please review a patch for MDEV-12416?

Thanks!

diff --git a/mysql-test/r/error_simulation.result b/mysql-test/r/error_simulation.result
index edb97d4..e0ec26b 100644
--- a/mysql-test/r/error_simulation.result
+++ b/mysql-test/r/error_simulation.result
@@ -121,3 +121,12 @@ a
 2
 #cleanup
 DROP TABLE t1, pid_table;
+#
+# MDEV-12416 OOM in create_virtual_tmp_table() makes the server crash
+#
+CREATE FUNCTION f1(a INT) RETURNS INT RETURN a;
+SET SESSION debug_dbug="+d,simulate_create_virtual_tmp_table_out_of_memory";
+SELECT f1(1);
+Got one of the listed errors
+DROP FUNCTION f1;
+SET SESSION debug_dbug=DEFAULT;
diff --git a/mysql-test/t/error_simulation.test b/mysql-test/t/error_simulation.test
index 7c343ed..beaaf60 100644
--- a/mysql-test/t/error_simulation.test
+++ b/mysql-test/t/error_simulation.test
@@ -148,3 +148,17 @@ SELECT a FROM t1 ORDER BY rand(1);
 
 --echo #cleanup
 DROP TABLE t1, pid_table;
+
+
+
+--echo #
+--echo # MDEV-12416 OOM in create_virtual_tmp_table() makes the server crash
+--echo #
+
+CREATE FUNCTION f1(a INT) RETURNS INT RETURN a;
+SET SESSION debug_dbug="+d,simulate_create_virtual_tmp_table_out_of_memory";
+# May fail with either ER_OUT_OF_RESOURCES or EE_OUTOFMEMORY
+--error ER_OUT_OF_RESOURCES, 5
+SELECT f1(1);
+DROP FUNCTION f1;
+SET SESSION debug_dbug=DEFAULT;
diff --git a/sql/sql_select.h b/sql/sql_select.h
index 0d4570f..e16d628 100644
--- a/sql/sql_select.h
+++ b/sql/sql_select.h
@@ -2025,6 +2025,7 @@ class Virtual_tmp_table: public TABLE
     @param thd         - Current thread.
   */
   static void *operator new(size_t size, THD *thd) throw();
+  static void operator delete(void *ptr, size_t size) { TRASH(ptr, size); }
 
   Virtual_tmp_table(THD *thd)
   {
@@ -2035,7 +2036,8 @@ class Virtual_tmp_table: public TABLE
 
   ~Virtual_tmp_table()
   {
-    destruct_fields();
+    if (s)
+      destruct_fields();
   }
 
   /**
@@ -2120,6 +2122,17 @@ create_virtual_tmp_table(THD *thd, List<Column_definition> &field_list)
   Virtual_tmp_table *table;
   if (!(table= new(thd) Virtual_tmp_table(thd)))
     return NULL;
+
+  /*
+    If "simulate_create_virtual_tmp_table_out_of_memory" debug option
+    is enabled, we now enable "simulate_out_of_memory". This effectively
+    makes table->init() fail on OOM inside multi_alloc_root().
+    This is done to test that ~Virtual_tmp_table() called from the "detele"
+    below correcly handle OOM.
+  */
+  DBUG_EXECUTE_IF("simulate_create_virtual_tmp_table_out_of_memory",
+                  DBUG_SET("+d,simulate_out_of_memory"););
+
   if (table->init(field_list.elements) ||
       table->add(field_list) ||
       table->open())