Crash on a trigger on update.
Error is:

201008  0:54:01 [ERROR] mysqld got signal 11 ;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.
To report this bug, see https://mariadb.com/kb/en/reporting-bugs
We will try our best to scrape up some info that will hopefully help
diagnose the problem, but since we have already crashed,
something is definitely wrong and this may fail.
Server version: 10.4.14-MariaDB-1:10.4.14+maria~bionic-log
key_buffer_size=134217728
read_buffer_size=2097152
max_used_connections=1
max_threads=102
thread_count=8
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 760256 K  bytes of memory
Hope that's ok; if not, decrease some variables in the equation.
Thread pointer: 0x7feb240013a8
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
stack_bottom = 0x7feb8c495dd8 thread_stack 0x49000
/usr/sbin/mysqld(my_print_stacktrace+0x2e)[0x55698b4f455e]
/usr/sbin/mysqld(handle_fatal_signal+0x515)[0x55698af6fea5]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x128a0)[0x7feb9618b8a0]
/usr/sbin/mysqld(_ZN13st_join_table7cleanupEv+0xa)[0x55698ada066a]
/usr/sbin/mysqld(_ZN4JOIN7cleanupEb+0x88)[0x55698ada0a28]
/usr/sbin/mysqld(_ZN4JOIN7destroyEv+0x46)[0x55698ada1156]
/usr/sbin/mysqld(_ZN13st_select_lex7cleanupEv+0x69)[0x55698ae00f39]
/usr/sbin/mysqld(_ZN30subselect_single_select_engine7prepareEP3THD+0x3c)[0x55698b0203ac]
/usr/sbin/mysqld(_ZN14Item_subselect10fix_fieldsEP3THDPP4Item+0x139)[0x55698b01fda9]
/usr/sbin/mysqld(_ZN9Item_func10fix_fieldsEP3THDPP4Item+0x153)[0x55698afd3b93]
/usr/sbin/mysqld(_ZN13Item_func_not10fix_fieldsEP3THDPP4Item+0x1be)[0x55698afa7f4e]
/usr/sbin/mysqld(_ZN9Item_cond10fix_fieldsEP3THDPP4Item+0x447)[0x55698afa8a87]
/usr/sbin/mysqld(_ZN3THD16sp_fix_func_itemEPP4Item+0x90)[0x55698acc75b0]
/usr/sbin/mysqld(_ZN3THD20sp_prepare_func_itemEPP4Itemj+0xf)[0x55698acc75cf]
/usr/sbin/mysqld(_ZN20sp_instr_jump_if_not9exec_coreEP3THDPj+0x1e)[0x55698acc762e]
/usr/sbin/mysqld(_ZN13sp_lex_keeper23reset_lex_and_exec_coreEP3THDPjbP8sp_instr+0x111)[0x55698accd4b1]
/usr/sbin/mysqld(_ZN7sp_head7executeEP3THDb+0x93d)[0x55698acc918d]
/usr/sbin/mysqld(_ZN7sp_head15execute_triggerEP3THDPK25st_mysql_const_lex_stringS4_P13st_grant_info+0x1b1)[0x55698acc9d01]
/usr/sbin/mysqld(_ZN19Table_triggers_list16process_triggersEP3THD14trg_event_type20trg_action_time_typeb+0x10c)[0x55698adf9d6c]
/usr/sbin/mysqld(_Z36fill_record_n_invoke_before_triggersP3THDP5TABLER4ListI4ItemES6_b14trg_event_type+0x86)[0x55698ad05226]
/usr/sbin/mysqld(_Z12mysql_updateP3THDP10TABLE_LISTR4ListI4ItemES6_PS4_jP8st_orderybPySA_+0x1749)[0x55698ae081c9]
/usr/sbin/mysqld(_Z21mysql_execute_commandP3THD+0x11c6)[0x55698ad5ee06]
/usr/sbin/mysqld(_Z11mysql_parseP3THDPcjP12Parser_statebb+0x1ea)[0x55698ad6608a]
/usr/sbin/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcjbb+0x13d5)[0x55698ad684e5]
/usr/sbin/mysqld(_Z10do_commandP3THD+0x104)[0x55698ad69c64]
/usr/sbin/mysqld(_Z24do_handle_one_connectionP7CONNECT+0x25e)[0x55698ae46c3e]
/usr/sbin/mysqld(handle_one_connection+0x3d)[0x55698ae46cfd]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x76db)[0x7feb961806db]
/lib/x86_64-linux-gnu/libc.so.6(clone+0x3f)[0x7feb94ba2a3f]
Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (0x7feb24012b40): update tbl_thing set name = concat(name)
Connection ID (thread ID): 50
Status: NOT_KILLED
Oct  8 00:54:01 ip-172-31-23-250 kernel: [  179.178884] mysqld[3415]: segfault at 1bef69 ip 000055698ada066a sp 00007feb8c4925d0 error 4 in mysqld[55698a6f2000+1442000]
Oct  8 00:54:01 ip-172-31-23-250 kernel: [  179.178890] Code: 49 8b 04 24 49 8b 7c 24 08 48 8b b0 98 02 00 00 e8 ab 80 1d 00 eb a6 90 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 54 53 48 89 fb <48> 8b 7f 08 48 85 ff 74 2d e8 08 fc 11 00 84 c0 74 24 48 8b 43 08
Optimizer switch: index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on



Repeatable test case: create a ubuntu 18.04 x86_64 on AWS.

$ apt-key adv --recv-keys --keyserver hkp://keyserver.ubuntu.com:80 0xF1656F24C74CD1D8
$ add-apt-repository "deb [arch=amd64,arm64,ppc64el] http://mariadb.mirror.liquidtelecom.com/repo/10.4/ubuntu $(lsb_release -cs) main"
$ apt-get install mariadb-client mariadb-server

$ mysql

create database main;
use main;

drop table tbl_thing_split; drop table tbl_thing_else; drop table tbl_thing;

CREATE TABLE `tbl_thing` (
  `THING_ID` varchar(50) CHARACTER SET ascii NOT NULL DEFAULT 'SOMEDEFAULT',
  `OIUYTRE_ID` int(10) unsigned NOT NULL DEFAULT 2610,
  `NAME` varchar(100) NOT NULL DEFAULT 'YSAM',
  `LOCATION` varchar(100) NOT NULL DEFAULT '',
  `xx_jhiusgdje` varchar(100) DEFAULT NULL,
  `JHGFDS_ID` int(10) unsigned NOT NULL DEFAULT 40,
  `MTHING_ID` varchar(50) CHARACTER SET ascii DEFAULT NULL,
  `BCD_EFG_CATEGORY_ID` int(10) unsigned NOT NULL DEFAULT 1291785531,
  `id_yuiop_thingid_set` varchar(20) DEFAULT NULL,
  `ZYXWVU_SET_ID` int(10) unsigned NOT NULL DEFAULT 400,
  `ABCDE_ID` int(10) NOT NULL DEFAULT 3,
  `YUI_SET_ID` int(10) NOT NULL DEFAULT 4113,
  `JHGFDSA_ID` int(10) NOT NULL DEFAULT 1,
  `OTHERTHING_ID` varchar(20) NOT NULL DEFAULT '11',
  `WELCOME_ID` int(10) unsigned NOT NULL DEFAULT 40002,
  `ABCDEF_SET_ID` int(20) NOT NULL DEFAULT 4000,
  `QWERTY_ID` int(10) NOT NULL DEFAULT 40,
  `MNBVCV_ID` int(10) NOT NULL DEFAULT 40,
  `sms_abcdeq_id` int(10) NOT NULL DEFAULT 41001,
  `id_affiliate` int(10) NOT NULL DEFAULT 0,
  `rfvgthnf_attribute_id` int(10) unsigned DEFAULT NULL,
  `NHYTGBVFR_ID` int(10) NOT NULL DEFAULT 50,
  `xyzzy_verification_something_type` enum('thing1','thing2','thing3','thing4') DEFAULT NULL,
  `send_missing_thing` bit(1) NOT NULL DEFAULT b'0',
  `send_plugh_eo` bit(1) NOT NULL DEFAULT b'0',
  `is_question` bit(1) NOT NULL DEFAULT b'0',
  `somewhere_page` varchar(100) default null,
  `somewhere_page_addtnl_params` text DEFAULT NULL,
  `last_modified` timestamp NOT NULL DEFAULT current_timestamp() ON UPDATE current_timestamp(),
  `last_modifying_user` varchar(81) CHARACTER SET utf8 DEFAULT 'unknown',
  `IS_ACTIVE` int(11) NOT NULL DEFAULT 1,
  PRIMARY KEY (`THING_ID`),
  KEY `IDX_THING_OIUYTRE_ID` (`OIUYTRE_ID`),
  KEY `IDX_THING_JHGFDS_ID` (`JHGFDS_ID`),
  KEY `IDX_THING_WELCOME_ID` (`WELCOME_ID`),
  KEY `FK_THING_ABCDEF_SET_ID` (`ABCDEF_SET_ID`),
  KEY `FK_THING_CONTENT_MNBVCV_ID` (`MNBVCV_ID`),
  KEY `FK_THING_CONTENT_ABCDE_ID` (`ABCDE_ID`),
  KEY `FK_THING_YUI_SET_ID` (`YUI_SET_ID`),
  KEY `FK_THING_NHYTGBVFR_ID` (`NHYTGBVFR_ID`),
  KEY `FK_THING_OTHERTHING_ID` (`OTHERTHING_ID`),
  KEY `FK_THING_BCD_EFG_CAT` (`BCD_EFG_CATEGORY_ID`),
  KEY `fk_tbl_thing_privacy_policy_id` (`QWERTY_ID`),
  KEY `fk_tbl_thing_testimonial_id` (`JHGFDSA_ID`),
  KEY `fk_tbl_thing_footer_set_id` (`ZYXWVU_SET_ID`),
  KEY `tbl_thing_ibfk_16` (`MTHING_ID`),
  KEY `tbl_thing_ibfk_17` (`rfvgthnf_attribute_id`),
  KEY `fk_id_yuiop_thingid_set` (`id_yuiop_thingid_set`),
  KEY `fk_id_affiliate` (`id_affiliate`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 COMMENT='Managed by P2 ContentServices and ehcache';


delimiter ;;
drop trigger main.tbl_thing_update;;

CREATE DEFINER=`root`@`localhost` TRIGGER `tbl_thing_update` BEFORE UPDATE ON `tbl_thing` FOR EACH ROW proc:BEGIN
    SET     NEW.THING_ID = UPPER(NEW.THING_ID) ;
    IF NOT (EXISTS (SELECT *
                       FROM    tbl_thing_split
                       WHERE   child_thingid = NEW.THING_ID
                               AND start_date < now())
               OR EXISTS (SELECT *
                          FROM tbl_thing_else
                          WHERE id_thing = NEW.THING_ID)) THEN
        SET     NEW.last_modified = now();
        IF USER() NOT LIKE 'baduser@%' OR new.last_modifying_user IS NULL THEN
                SET new.last_modifying_user = USER();
        END IF;
    ELSE
        SIGNAL SQLSTATE '45000'
        SET MESSAGE_TEXT = 'some message which was here';
    END IF;
END
;;
delimiter ;

create table tbl_thing_split ( child_thingid int(10),start_date datetime );
create table tbl_thing_else ( id_thing varchar(50) );

insert into `tbl_thing` (
`THING_ID`,
`OIUYTRE_ID`,
`NAME`,
`LOCATION`,
`xx_jhiusgdje`,
`JHGFDS_ID`,
`MTHING_ID`,
`BCD_EFG_CATEGORY_ID`,
`id_yuiop_thingid_set`,
`ZYXWVU_SET_ID` ) values ( 
'testthing',
'1234',
'testname',
'testloc',
'testnothing',
'4567',
'testmthing',
'9876',
'abcdef',
'76384'
);

update tbl_thing set name = concat(name);
update tbl_thing set name = concat(name);
update tbl_thing set name = concat(name);
update tbl_thing set name = concat(name);
-- crashes before here ---