MDEV-40147 MSAN: use-of-uninitialized-value in my_time_compare

Field::get_date and Item::get_date can return true and not
have their ltime pointer structure initialized.

This was the case with Field_vers_trx_id::get_date.

Type_handler_time_common::stored_field_cmp_to_item rather
than doing a my_time_compare on uninitialized values can
return a non-equality (!=0) value for when the fetching of
Field or Item fails and avoid the call to my_time_compare.

Added checks for other invalid results before being
passed to my_time_compare.

Add nonnull as an attribute on my_time_compare and the
unpack_time function it used. Also pack_time since related
and it obviously requires a non-null argument.

Reviewed by: Alexey Midenkov

mysql-test/suite/versioning/r/trx_id.result

@@ -611,3 +611,21 @@ ERROR HY000: Lock wait timeout exceeded; try restarting transaction
 disconnect con1;
 connection default;
 drop table t1;
+#
+# MDEV-40147 MSAN: use-of-uninitialized-value in my_time_compare
+#
+create table t (
+a int,
+row_start bigint unsigned generated always as row start,
+row_end bigint unsigned generated always as row end,
+period for system_time (row_start, row_end)
+) with system versioning engine=InnoDB;
+insert into t () values ();
+analyze table t persistent for all;
+Table	Op	Msg_type	Msg_text
+test.t	analyze	status	Engine-independent statistics collected
+test.t	analyze	status	OK
+select * from t where row_end > current_time();
+ERROR HY000: TRX_ID ... not found in `mysql.transaction_registry`
+drop table t;
+# End of 10.11 tests

mysql-test/suite/versioning/t/trx_id.test

@@ -643,3 +643,26 @@ alter table xx;
 --disconnect con1
 --connection default
 drop table t1;
+
+--echo #
+--echo # MDEV-40147 MSAN: use-of-uninitialized-value in my_time_compare
+--echo #
+
+create table t (
+  a int,
+  row_start bigint unsigned generated always as row start,
+  row_end bigint unsigned generated always as row end,
+  period for system_time (row_start, row_end)
+) with system versioning engine=InnoDB;
+
+insert into t () values ();
+
+analyze table t persistent for all;
+
+--replace_regex /TRX_ID \d+/TRX_ID .../
+--error ER_VERS_NO_TRX_ID
+select * from t where row_end > current_time();
+
+drop table t;
+
+--echo # End of 10.11 tests

sql/sql_time.h

@@ -121,7 +121,8 @@ int append_interval(String *str, interval_type int_type,
 */
 bool calc_time_diff(const MYSQL_TIME *l_time1, const MYSQL_TIME *l_time2,
                     int lsign, MYSQL_TIME *l_time3, date_mode_t fuzzydate);
-int my_time_compare(const MYSQL_TIME *a, const MYSQL_TIME *b);
+int my_time_compare(const MYSQL_TIME *a, const MYSQL_TIME *b)
+                    __attribute__((nonnull));
 void localtime_to_TIME(MYSQL_TIME *to, struct tm *from);
 
 void calc_time_from_sec(MYSQL_TIME *to, ulong seconds, ulong microseconds);
@@ -183,8 +184,10 @@ check_date_with_warn(THD *thd, const MYSQL_TIME *ltime,
 
 bool adjust_time_range_with_warn(THD *thd, MYSQL_TIME *ltime, uint dec);
 
-longlong pack_time(const MYSQL_TIME *my_time);
+longlong pack_time(const MYSQL_TIME *my_time)
+                   __attribute__((nonnull));
 void unpack_time(longlong packed, MYSQL_TIME *my_time,
-                 enum_mysql_timestamp_type ts_type);
+                 enum_mysql_timestamp_type ts_type)
+                 __attribute__((nonnull));
 
 #endif /* SQL_TIME_INCLUDED */

sql/sql_type.cc

@@ -8951,7 +8951,7 @@ Type_handler_temporal_result::Item_const_eq(const Item_const *a,
 {
   const MYSQL_TIME *ta= a->const_ptr_mysql_time();
   const MYSQL_TIME *tb= b->const_ptr_mysql_time();
-  return !my_time_compare(ta, tb) &&
+  return ta && tb && !my_time_compare(ta, tb) &&
          (!binary_cmp ||
           a->get_type_all_attributes_from_const()->decimals ==
           b->get_type_all_attributes_from_const()->decimals);
@@ -9107,8 +9107,9 @@ int Type_handler_temporal_with_date::stored_field_cmp_to_item(THD *thd,
                                                               Item *item) const
 {
   MYSQL_TIME field_time, item_time, item_time2, *item_time_cmp= &item_time;
-  field->get_date(&field_time, Datetime::Options(TIME_INVALID_DATES, thd));
-  item->get_date(thd, &item_time, Datetime::Options(TIME_INVALID_DATES, thd));
+  if (field->get_date(&field_time, Datetime::Options(TIME_INVALID_DATES, thd))
+      || item->get_date(thd, &item_time, Datetime::Options(TIME_INVALID_DATES, thd)))
+    return -1;
   if (item_time.time_type == MYSQL_TIMESTAMP_TIME &&
       time_to_datetime(thd, &item_time, item_time_cmp= &item_time2))
     return 1;
@@ -9121,8 +9122,9 @@ int Type_handler_time_common::stored_field_cmp_to_item(THD *thd,
                                                        Item *item) const
 {
   MYSQL_TIME field_time, item_time;
-  field->get_date(&field_time, Time::Options(thd));
-  item->get_date(thd, &item_time, Time::Options(thd));
+  if (field->get_date(&field_time, Time::Options(thd))
+      || item->get_date(thd, &item_time, Time::Options(thd)))
+    return -1; /* !=0 is important, and avoid my_time_compare */
   return my_time_compare(&field_time, &item_time);
 }