This crash is a proxy for various run-time errors. I have two reproductions:

Reproduction 1: subquery cannot be executed because "The storage engine for the table doesn't support IDB-1001: Function 'whatever' isn't supported.
Test 1: as reported:
MariaDB [gjd]> create table t2 (a int) engine=Columnstore;
Query OK, 0 rows affected (0.664 sec)

MariaDB [gjd]> insert into t2 values (1),(2);
Query OK, 2 rows affected (0.192 sec)
Records: 2 Duplicates: 0 Warnings: 0

MariaDB [gjd]>
MariaDB [gjd]> select count>0 from t2;
ERROR 1178 (42000): The storage engine for the table doesn't support IDB-1001: Function '>' isn't supported.
MariaDB [gjd]> select * from t2 where (select count>0 from t2);
ERROR 1815 (HY000): Internal error: Lost connection to ExeMgr. Please contact your administrator

Test 2. Another reproduction
MariaDB [gjd]> drop table if exists t3;
Query OK, 0 rows affected (0.357 sec)

MariaDB [gjd]> create table t3 (a int, b datetime) engine=Columnstore;
Query OK, 0 rows affected (0.592 sec)

MariaDB [gjd]> insert into t3 values (1,'2008-05-15 12:00:00');
Query OK, 1 row affected (1.165 sec)

MariaDB [gjd]>
MariaDB [gjd]> select convert_tz(b,'UTC','America/New_York') from t3;
ERROR 1178 (42000): The storage engine for the table doesn't support IDB-1001: Function 'convert_tz' isn't supported.
MariaDB [gjd]> select * from t3 where (select convert_tz(b,'UTC','America/New_York') from t3);
ERROR 1815 (HY000): Internal error: Lost connection to ExeMgr. Please contact your administrator

(why convert_tz is not supported, is a different ticker - MCOL-4375, used here just as another proofpoint)

Reproduction 2. It is supposed to be run-time error.
Test 1. Using InnoDB
MariaDB [gjd]> select * from t2i where (select true from t2i);
ERROR 1242 (21000): Subquery returns more than 1 row

Test 1.2 Using Columnstore:
MariaDB [gjd]> select * from t2 where (select true from t2);
ERROR 1815 (HY000): Internal error: Lost connection to ExeMgr. Please contact your administrator