Index: sql/sql_acl.cc
===================================================================
--- sql/sql_acl.cc	(revision 1)
+++ sql/sql_acl.cc	(working copy)
@@ -7810,6 +7810,13 @@
   bool save_binlog_row_based;
   DBUG_ENTER("mysql_user_password_expire");
 
+  /* without check, the next operations will cause crash */
+  if (!initialized)
+  {
+    my_error(ER_OPTION_PREVENTS_STATEMENT, MYF(0), "--skip-grant-tables");
+    DBUG_RETURN(-1);
+  }
+
   tables.init_one_table("mysql", 5, "user", 4, "user", TL_WRITE);
 
 #ifdef HAVE_REPLICATION