From 47812017c67f1cba46cbc9dceee4c613a00dfd94 Mon Sep 17 00:00:00 2001 From: Brandon Nesterenko Date: Tue, 10 May 2022 14:25:35 -0600 Subject: MDEV-28530: Revoking privileges from a non-existing user on a master breaks replication on the slave in the presence of replication filters Problem: ======== Replication can break while applying a query log event if its respective command errors on the primary, but is ignored by the replication filter within Grant_tables on the replica. The bug reported by MDEV-28530 shows this with REVOKE ALL PRIVILEGES using a non-existent user. The primary will binlog the REVOKE command with an error code, and the replica will think the command executed with success because the replication filter will ignore the command while accessing the Grant_tables classes. When the replica performs an error check, it sees the difference between the error codes, and replication breaks. Solution: ======== If the replication filter check done by Grant_tables logic ignores the tables, reset thd->slave_expected_error to 0 so that Query_log_event::do_apply_event() can be made aware that the underlying query was ignored when it compares errors. Note that this bug also effects DROP USER if not all users exist in the provided list, and the patch fixes and tests this case. Reviewed By: ============ andrei.elkin@mariadb.com --- sql/log_event.cc | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'sql/log_event.cc') diff --git a/sql/log_event.cc b/sql/log_event.cc index 3639b7a5d00..a5a31d57ed2 100644 --- a/sql/log_event.cc +++ b/sql/log_event.cc @@ -5703,6 +5703,13 @@ int Query_log_event::do_apply_event(rpl_group_info *rgi, thd->update_server_status(); log_slow_statement(thd); thd->lex->restore_set_statement_var(); + + /* + When THD::slave_expected_error gets reset inside execution stack + that is the case of to be ignored event. In this case the expected + error must change to the reset value as well. + */ + expected_error= thd->slave_expected_error; } thd->variables.option_bits&= ~OPTION_MASTER_SQL_ERROR; -- cgit v1.2.1