A fix and a test case for Bug#34166 Server crash in SHOW OPEN TABLES and

pre-locking.

The crash was caused by an implicit assumption in check_table_access() that
table_list parameter is always a part of lex->query_tables.

When iterating over the passed list of tables, check_table_access() used
to stop only when lex->query_tables_last_not_own was reached. 
In case of pre-locking, lex->query_tables_last_own is not NULL and points
to some element of lex->query_tables. When the parameter
of check_table_access() was not part of lex->query_tables, loop invariant
could never be violated and a crash would happen when the current table
pointer would point beyond the end of the provided list.

The fix is to change the signature of check_table_access() to also accept
a numeric limit of loop iterations, similarly to check_grant(), and 
supply this limit in all places when we want to check access of tables
that are outside lex->query_tables, or just want to check access to one table.


mysql-test/r/information_schema.result:
  Update test results (Bug#34166).
mysql-test/t/information_schema.test:
  Add a test case for Bug#34166.
sql/mysql_priv.h:
  Change signature of check_table_access() to accept a numeric limit
  of tables to check.
sql/sp_head.cc:
  Update to the new signature of check_table_access().
sql/sql_acl.cc:
  Improve code clarity: if there is a numeric limit, we should not need
  to look at first_not_own_table.
sql/sql_base.cc:
  Update to the new signature of check_table_access().
sql/sql_cache.cc:
  Update to the new signature of check_table_access().
sql/sql_parse.cc:
  Update to the new signature of check_table_access().
  Change check_table_access() to accept an optional numeric limit of tables
  to check. A crash would happen when check_table_access() was
  passed a list of tables that is not part of lex->query_tables and
  lex->query_tables_last_own was not NULL.
sql/sql_plugin.cc:
  Update to the new signature of check_table_access().
sql/sql_prepare.cc:
  Update to the new signature of check_table_access().
sql/sql_show.cc:
  Update to the new signature of check_table_access().
  Ensure that check_table_access() only checks access to the first
  table in the table list when called from list_open_tables().
  list_open_tables() supplies a table list that is created on stack,
  whereas check_table_access() used to assume that the supplied list is a part
  of thd->lex.
sql/sql_trigger.cc:
  Update to the new signature of check_table_access().
sql/sql_view.cc:
  Update to the new signature of check_table_access().

1 files changed, 2 insertions, 2 deletions

diff --git a/sql/sp_head.cc b/sql/sp_head.cc
index 74f5bf55828..036101021f5 100644
--- a/sql/sp_head.cc
+++ b/sql/sp_head.cc
@@ -2265,7 +2265,7 @@ bool check_show_routine_access(THD *thd, sp_head *sp, bool *full_access)
   bzero((char*) &tables,sizeof(tables));
   tables.db= (char*) "mysql";
   tables.table_name= tables.alias= (char*) "proc";
-  *full_access= (!check_table_access(thd, SELECT_ACL, &tables, 1) ||
+  *full_access= (!check_table_access(thd, SELECT_ACL, &tables, 1, TRUE) ||
                  (!strcmp(sp->m_definer_user.str,
                           thd->security_ctx->priv_user) &&
                   !strcmp(sp->m_definer_host.str,
@@ -2712,7 +2712,7 @@ int sp_instr::exec_open_and_lock_tables(THD *thd, TABLE_LIST *tables)
     Check whenever we have access to tables for this statement
     and open and lock them before executing instructions core function.
   */
-  if (check_table_access(thd, SELECT_ACL, tables, 0)
+  if (check_table_access(thd, SELECT_ACL, tables, UINT_MAX, FALSE)
       || open_and_lock_tables(thd, tables))
     result= -1;
   else