I tried to reproduce this with exact same version and by using your my.cnf but no avail. I couldn't reproduce this problem.

mysql> SHOW VARIABLES LIKE '%version%';
+-------------------------+------------------------------------------------------+
| Variable_name           | Value                                                |
+-------------------------+------------------------------------------------------+
| innodb_version          | 5.6.35-81.0                                          |
| protocol_version        | 10                                                   |
| slave_type_conversions  |                                                      |
| tls_version             | TLSv1.1,TLSv1.2                                      |
| tokudb_version          | 5.6.35-81.0                                          |
| version                 | 5.6.35-81.0-log                                      |
| version_comment         | Percona Server (GPL), Release 81.0, Revision c96c427 |
| version_compile_machine | x86_64                                               |
| version_compile_os      | Linux                                                |
+-------------------------+------------------------------------------------------+
9 rows in set (0.00 sec)

-- created test tables using InnoDB and TokuDB engines.

mysql> use information_schema
mysql> show tables;
79 rows in set (0.00 sec)

mysql> SELECT * FROM TABLES;
161 rows in set (0.03 sec)

mysql> SHOW ENGINES; 
+--------------------+---------+----------------------------------------------------------------------------+--------------+------+------------+
| Engine             | Support | Comment                                                                    | Transactions | XA   | Savepoints |
+--------------------+---------+----------------------------------------------------------------------------+--------------+------+------------+
| CSV                | YES     | CSV storage engine                                                         | NO           | NO   | NO         |
| MRG_MYISAM         | YES     | Collection of identical MyISAM tables                                      | NO           | NO   | NO         |
| MEMORY             | YES     | Hash based, stored in memory, useful for temporary tables                  | NO           | NO   | NO         |
| BLACKHOLE          | YES     | /dev/null storage engine (anything you write to it disappears)             | NO           | NO   | NO         |
| MyISAM             | YES     | MyISAM storage engine                                                      | NO           | NO   | NO         |
| TokuDB             | YES     | Percona TokuDB Storage Engine with Fractal Tree(tm) Technology             | YES          | YES  | YES        |
| PERFORMANCE_SCHEMA | YES     | Performance Schema                                                         | NO           | NO   | NO         |
| ARCHIVE            | YES     | Archive storage engine                                                     | NO           | NO   | NO         |
| FEDERATED          | NO      | Federated MySQL storage engine                                             | NULL         | NULL | NULL       |
| InnoDB             | DEFAULT | Percona-XtraDB, Supports transactions, row-level locking, and foreign keys | YES          | YES  | YES        |
+--------------------+---------+----------------------------------------------------------------------------+--------------+------+------------+
10 rows in set (0.00 sec)

I even tried to query information_schema tables randomly through script but no crashes either.