free(): invalid pointer
210109 15:00:04 [ERROR] mysqld got signal 6 ;
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: 10.3.27-MariaDB-0+deb10u1-log
key_buffer_size=536870912
read_buffer_size=131072
max_used_connections=62
max_threads=802
thread_count=42
It is possible that mysqld could use up to 
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 2287487 K  bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x0
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 = 0x0 thread_stack 0x30000
/usr/sbin/mysqld(my_print_stacktrace+0x2e)[0x55f35b1a291e]
/usr/sbin/mysqld(handle_fatal_signal+0x54d)[0x55f35acd12ed]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x12730)[0x7f14ccf4a730]
/lib/x86_64-linux-gnu/libc.so.6(gsignal+0x10b)[0x7f14cc5077bb]
/lib/x86_64-linux-gnu/libc.so.6(abort+0x121)[0x7f14cc4f2535]
/lib/x86_64-linux-gnu/libc.so.6(+0x79508)[0x7f14cc549508]
/lib/x86_64-linux-gnu/libc.so.6(+0x7fc1a)[0x7f14cc54fc1a]
/lib/x86_64-linux-gnu/libc.so.6(+0x8142c)[0x7f14cc55142c]
/lib/x86_64-linux-gnu/libc.so.6(+0x84af3)[0x7f14cc554af3]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x7fc9)[0x7f14ccf3ffc9]
/lib/x86_64-linux-gnu/libc.so.6(clone+0x3f)[0x7f14cc5c94cf]
The manual page at https://mariadb.com/kb/en/how-to-produce-a-full-stack-trace-for-mysqld/ contains
information that should help you find out what is causing the crash.
Writing a core file...
Working directory at /var/lib/mysql
Resource Limits:
Fatal signal 11 while backtracing
2021-01-09 15:00:10 0 [Note] InnoDB: Using Linux native AIO
2021-01-09 15:00:10 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2021-01-09 15:00:10 0 [Note] InnoDB: Uses event mutexes
2021-01-09 15:00:10 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
2021-01-09 15:00:10 0 [Note] InnoDB: Number of pools: 1
2021-01-09 15:00:10 0 [Note] InnoDB: Using SSE2 crc32 instructions
2021-01-09 15:00:10 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
2021-01-09 15:00:10 0 [Note] InnoDB: Completed initialization of buffer pool
2021-01-09 15:00:10 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2021-01-09 15:00:10 0 [Note] InnoDB: Starting crash recovery from checkpoint LSN=64644280081
2021-01-09 15:00:10 0 [Note] InnoDB: Starting final batch to recover 15 pages from redo log.
2021-01-09 15:00:11 0 [Note] InnoDB: 128 out of 128 rollback segments are active.
2021-01-09 15:00:11 0 [Note] InnoDB: Removed temporary tablespace data file: "ibtmp1"
2021-01-09 15:00:11 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2021-01-09 15:00:11 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
2021-01-09 15:00:11 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.
2021-01-09 15:00:11 0 [Note] InnoDB: 10.3.27 started; log sequence number 64644289043; transaction id 14280495
2021-01-09 15:00:11 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool
2021-01-09 15:00:11 0 [Note] Plugin 'FEEDBACK' is disabled.
2021-01-09 15:00:11 0 [Note] Recovering after a crash using tc.log
2021-01-09 15:00:11 0 [Note] Starting crash recovery...
2021-01-09 15:00:11 0 [Note] Crash recovery finished.
2021-01-09 15:00:11 0 [Note] Server socket created on IP: '0.0.0.0'.
2021-01-09 15:00:11 0 [Note] Reading of all Master_info entries succeeded
2021-01-09 15:00:11 0 [Note] Added new Master_info '' to hash table
2021-01-09 15:00:11 0 [Note] /usr/sbin/mysqld: ready for connections.
Version: '10.3.27-MariaDB-0+deb10u1-log'  socket: '/run/mysqld/mysqld.sock'  port: 3306  Debian 10
2021-01-09 15:00:11 0 [Note] InnoDB: Buffer pool(s) load completed at 210109 15:00:11
2021-01-09 15:00:11 8 [ERROR] mysqld: Table './outsourcing/ci_sessions' is marked as crashed and should be repaired
2021-01-09 15:00:11 8 [Warning] Checking table:   './outsourcing/ci_sessions'
2021-01-09 15:00:11 8 [ERROR] mysqld: Table './outsourcing/user' is marked as crashed and should be repaired
2021-01-09 15:00:11 8 [Warning] Checking table:   './outsourcing/user'
2021-01-09 15:00:11 9 [Warning] Access denied for user 'root'@'localhost' (using password: NO)
2021-01-09 15:00:11 10 [Warning] Access denied for user 'root'@'localhost' (using password: NO)
2021-01-09 15:00:11 39 [ERROR] mysqld: Table './outsourcing/checklist_data' is marked as crashed and should be repaired
2021-01-09 15:00:11 39 [Warning] Checking table:   './outsourcing/checklist_data'
2021-01-09 15:00:12 40 [ERROR] mysqld: Table './msg/ci_sessions' is marked as crashed and should be repaired
2021-01-09 15:00:12 40 [Warning] Checking table:   './msg/ci_sessions'
2021-01-09 15:00:12 41 [ERROR] mysqld: Table './msg/user' is marked as crashed and should be repaired
2021-01-09 15:00:12 41 [Warning] Checking table:   './msg/user'
2021-01-09 15:00:13 13 [ERROR] mysqld: Table './outsourcing/users_action_log' is marked as crashed and should be repaired
2021-01-09 15:00:13 13 [Warning] Checking table:   './outsourcing/users_action_log'
2021-01-09 15:00:14 51 [ERROR] mysqld: Table './outsourcing/vats_history' is marked as crashed and should be repaired
2021-01-09 15:00:14 51 [Warning] Checking table:   './outsourcing/vats_history'
2021-01-09 15:00:16 55 [ERROR] mysqld: Table './outsourcing/object' is marked as crashed and should be repaired
2021-01-09 15:00:16 55 [Warning] Checking table:   './outsourcing/object'
2021-01-09 15:00:16 55 [ERROR] mysqld: Table './outsourcing/employee_client' is marked as crashed and should be repaired
2021-01-09 15:00:16 55 [Warning] Checking table:   './outsourcing/employee_client'
2021-01-09 15:00:16 56 [ERROR] mysqld: Table './outsourcing/vats_realtime_call' is marked as crashed and should be repaired
2021-01-09 15:00:16 56 [Warning] Checking table:   './outsourcing/vats_realtime_call'
2021-01-09 15:00:17 60 [ERROR] mysqld: Table './fv/ci_sessions' is marked as crashed and should be repaired
2021-01-09 15:00:17 60 [Warning] Checking table:   './fv/ci_sessions'
2021-01-09 15:00:17 60 [ERROR] mysqld: Table './fv/user' is marked as crashed and should be repaired
2021-01-09 15:00:17 60 [Warning] Checking table:   './fv/user'
2021-01-09 15:00:18 70 [ERROR] mysqld: Table './outsourcing/object_perms' is marked as crashed and should be repaired
2021-01-09 15:00:18 70 [Warning] Checking table:   './outsourcing/object_perms'
2021-01-09 15:00:18 78 [ERROR] mysqld: Table './outsourcing/checklist_export' is marked as crashed and should be repaired
2021-01-09 15:00:18 78 [Warning] Checking table:   './outsourcing/checklist_export'
2021-01-09 15:00:18 80 [ERROR] mysqld: Table './outsourcing/candidate_history_status' is marked as crashed and should be repaired
2021-01-09 15:00:18 80 [Warning] Checking table:   './outsourcing/candidate_history_status'
2021-01-09 15:00:20 85 [ERROR] mysqld: Table './outsourcing/paid_money' is marked as crashed and should be repaired
2021-01-09 15:00:20 85 [Warning] Checking table:   './outsourcing/paid_money'
2021-01-09 15:00:25 93 [ERROR] mysqld: Table './outsourcing/employee_salary' is marked as crashed and should be repaired
2021-01-09 15:00:25 93 [Warning] Checking table:   './outsourcing/employee_salary'
2021-01-09 15:00:25 96 [ERROR] mysqld: Table './outsourcing/paid_money_period' is marked as crashed and should be repaired
2021-01-09 15:00:25 96 [Warning] Checking table:   './outsourcing/paid_money_period'
2021-01-09 15:00:26 97 [ERROR] mysqld: Table './outsourcing/paid_money_budget_and_articles' is marked as crashed and should be repaired
2021-01-09 15:00:26 97 [Warning] Checking table:   './outsourcing/paid_money_budget_and_articles'
2021-01-09 15:00:27 52 [ERROR] mysqld: Table './ars/ci_sessions' is marked as crashed and should be repaired
2021-01-09 15:00:27 52 [Warning] Checking table:   './ars/ci_sessions'
2021-01-09 15:00:27 52 [ERROR] mysqld: Table './ars/employee' is marked as crashed and should be repaired
2021-01-09 15:00:27 52 [Warning] Checking table:   './ars/employee'
2021-01-09 15:00:27 101 [ERROR] mysqld: Table './outsourcing/shift' is marked as crashed and should be repaired
2021-01-09 15:00:27 101 [Warning] Checking table:   './outsourcing/shift'
2021-01-09 15:00:28 110 [ERROR] mysqld: Table './outsourcing/nsms_simple_message' is marked as crashed and should be repaired
2021-01-09 15:00:28 110 [Warning] Checking table:   './outsourcing/nsms_simple_message'
2021-01-09 15:00:28 112 [ERROR] mysqld: Table './outsourcing/employee_interview' is marked as crashed and should be repaired
2021-01-09 15:00:28 112 [Warning] Checking table:   './outsourcing/employee_interview'
2021-01-09 15:00:28 120 [ERROR] mysqld: Table './outsourcing/shift_mass' is marked as crashed and should be repaired
2021-01-09 15:00:28 120 [Warning] Checking table:   './outsourcing/shift_mass'
2021-01-09 15:00:28 124 [ERROR] mysqld: Table './outsourcing/employee_experience' is marked as crashed and should be repaired
2021-01-09 15:00:28 124 [Warning] Checking table:   './outsourcing/employee_experience'
2021-01-09 15:00:29 131 [ERROR] mysqld: Table './outsourcing/checklist' is marked as crashed and should be repaired
2021-01-09 15:00:29 131 [Warning] Checking table:   './outsourcing/checklist'
2021-01-09 15:00:30 132 [ERROR] mysqld: Table './outsourcing/employee_history' is marked as crashed and should be repaired
2021-01-09 15:00:30 132 [Warning] Checking table:   './outsourcing/employee_history'
2021-01-09 15:00:31 41 [ERROR] mysqld: Table './pplfast/ci_sessions' is marked as crashed and should be repaired
2021-01-09 15:00:31 41 [Warning] Checking table:   './pplfast/ci_sessions'
2021-01-09 15:00:34 133 [ERROR] mysqld: Table './outsourcing/employee_metro' is marked as crashed and should be repaired
2021-01-09 15:00:34 133 [Warning] Checking table:   './outsourcing/employee_metro'
2021-01-09 15:00:34 134 [ERROR] mysqld: Table './outsourcing/employee_contact' is marked as crashed and should be repaired
2021-01-09 15:00:34 134 [Warning] Checking table:   './outsourcing/employee_contact'
2021-01-09 15:00:35 137 [ERROR] mysqld: Table './outsourcing/fl_job_patent' is marked as crashed and should be repaired
2021-01-09 15:00:35 137 [Warning] Checking table:   './outsourcing/fl_job_patent'
2021-01-09 15:00:35 139 [ERROR] mysqld: Table './outsourcing/employee_action_log' is marked as crashed and should be repaired
2021-01-09 15:00:35 139 [Warning] Checking table:   './outsourcing/employee_action_log'
2021-01-09 15:00:37 144 [ERROR] mysqld: Table './outsourcing/paid_money_goods_and_services' is marked as crashed and should be repaired
2021-01-09 15:00:37 144 [Warning] Checking table:   './outsourcing/paid_money_goods_and_services'
2021-01-09 15:00:38 149 [ERROR] mysqld: Table './outsourcing/plan' is marked as crashed and should be repaired
2021-01-09 15:00:38 149 [Warning] Checking table:   './outsourcing/plan'
2021-01-09 15:00:44 152 [ERROR] mysqld: Table './outsourcing/employee_notifications' is marked as crashed and should be repaired
2021-01-09 15:00:44 152 [Warning] Checking table:   './outsourcing/employee_notifications'
2021-01-09 15:00:44 153 [ERROR] mysqld: Table './outsourcing/employee_deduction' is marked as crashed and should be repaired
2021-01-09 15:00:44 153 [Warning] Checking table:   './outsourcing/employee_deduction'
2021-01-09 15:00:44 159 [ERROR] mysqld: Table './outsourcing/shift_template' is marked as crashed and should be repaired
2021-01-09 15:00:44 159 [Warning] Checking table:   './outsourcing/shift_template'
2021-01-09 15:00:45 166 [ERROR] mysqld: Table './outsourcing/vats_realtime_call_check' is marked as crashed and should be repaired
2021-01-09 15:00:45 166 [Warning] Checking table:   './outsourcing/vats_realtime_call_check'
2021-01-09 15:00:46 284 [ERROR] mysqld: Table './ars/interview' is marked as crashed and should be repaired
2021-01-09 15:00:46 284 [Warning] Checking table:   './ars/interview'
2021-01-09 15:00:46 288 [ERROR] mysqld: Table './ars/candidate_history_status' is marked as crashed and should be repaired
2021-01-09 15:00:46 288 [Warning] Checking table:   './ars/candidate_history_status'
2021-01-09 15:00:47 316 [ERROR] mysqld: Table './ars/employee_interview' is marked as crashed and should be repaired
2021-01-09 15:00:47 316 [Warning] Checking table:   './ars/employee_interview'
2021-01-09 15:00:47 327 [ERROR] mysqld: Table './ars/employee_experience' is marked as crashed and should be repaired
2021-01-09 15:00:47 327 [Warning] Checking table:   './ars/employee_experience'
2021-01-09 15:00:47 336 [ERROR] mysqld: Table './ars/employee_history' is marked as crashed and should be repaired
2021-01-09 15:00:47 336 [Warning] Checking table:   './ars/employee_history'
2021-01-09 15:00:47 338 [ERROR] mysqld: Table './ars/employee_contact' is marked as crashed and should be repaired
2021-01-09 15:00:47 338 [Warning] Checking table:   './ars/employee_contact'
2021-01-09 15:00:47 342 [ERROR] mysqld: Table './ars/employee_action_log' is marked as crashed and should be repaired
2021-01-09 15:00:47 342 [Warning] Checking table:   './ars/employee_action_log'
2021-01-09 15:00:47 354 [ERROR] mysqld: Table './ars/employee_notifications' is marked as crashed and should be repaired
2021-01-09 15:00:47 354 [Warning] Checking table:   './ars/employee_notifications'
2021-01-09 15:00:47 357 [ERROR] mysqld: Table './ars/users_action_log' is marked as crashed and should be repaired
2021-01-09 15:00:47 357 [Warning] Checking table:   './ars/users_action_log'
2021-01-09 15:00:49 465 [ERROR] mysqld: Table './fv/users_action_log' is marked as crashed and should be repaired
2021-01-09 15:00:49 465 [Warning] Checking table:   './fv/users_action_log'
2021-01-09 15:00:51 679 [ERROR] mysqld: Table './pplfast/users_action_log' is marked as crashed and should be repaired
2021-01-09 15:00:51 679 [Warning] Checking table:   './pplfast/users_action_log'
2021-01-09 15:00:52 718 [ERROR] mysqld: Table './msg/candidate_history_status' is marked as crashed and should be repaired
2021-01-09 15:00:52 718 [Warning] Checking table:   './msg/candidate_history_status'
2021-01-09 15:00:53 757 [ERROR] mysqld: Table './msg/employee_experience' is marked as crashed and should be repaired
2021-01-09 15:00:53 757 [Warning] Checking table:   './msg/employee_experience'
2021-01-09 15:00:53 765 [ERROR] mysqld: Table './msg/employee_history' is marked as crashed and should be repaired
2021-01-09 15:00:53 765 [Warning] Checking table:   './msg/employee_history'
2021-01-09 15:00:54 767 [ERROR] mysqld: Table './msg/employee_contact' is marked as crashed and should be repaired
2021-01-09 15:00:54 767 [Warning] Checking table:   './msg/employee_contact'
2021-01-09 15:00:54 771 [ERROR] mysqld: Table './msg/employee_action_log' is marked as crashed and should be repaired
2021-01-09 15:00:54 771 [Warning] Checking table:   './msg/employee_action_log'
2021-01-09 15:00:54 786 [ERROR] mysqld: Table './msg/users_action_log' is marked as crashed and should be repaired
2021-01-09 15:00:54 786 [Warning] Checking table:   './msg/users_action_log'
2021-01-09 15:00:55 801 [ERROR] mysqld: Table './msg/employee_client' is marked as crashed and should be repaired
2021-01-09 15:00:55 801 [Warning] Checking table:   './msg/employee_client'