SIGSEGV in Sys_var_sesvartrack::session_save_default |SIGSEGV in __strlen_avx2

SET GLOBAL session_track_system_variables='a';

SET SESSION session_track_system_variables=DEFAULT;

Core was generated by `/test/MD150421-mariadb-10.6.0-linux-x86_64-opt/bin/mysqld --no-defaults --core-'.

Program terminated with signal SIGSEGV, Segmentation fault.

#0  __strlen_avx2 () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:65

[Current thread is 1 (Thread 0x1460d80d7700 (LWP 231047))]

(gdb) bt

#0  __strlen_avx2 () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:65

#1  0x00005623cbbf5585 in Sys_var_sesvartrack::session_save_default (this=<optimized out>, thd=0x146088000c58, var=0x1460880105b8) at /test/10.6_opt/sql/sys_vars.ic:677

#2  0x00005623cba22c13 in sys_var::set_default (this=0x5623ccbe3060 <Sys_track_session_sys_vars>, thd=0x146088000c58, var=0x1460880105b8) at /test/10.6_opt/sql/set_var.cc:291

#3  0x00005623cba22c65 in set_var::update (thd=<optimized out>, this=<optimized out>) at /test/10.6_opt/sql/set_var.cc:857

#4  set_var::update (this=<optimized out>, thd=<optimized out>) at /test/10.6_opt/sql/set_var.cc:857

#5  0x00005623cba23e09 in sql_set_variables (thd=thd@entry=0x146088000c58, var_list=var_list@entry=0x146088005ba0, free=free@entry=true) at /test/10.6_opt/sql/set_var.cc:746

#6  0x00005623cbae1056 in mysql_execute_command (thd=0x146088000c58) at /test/10.6_opt/sql/sql_parse.cc:5030

#7  0x00005623cbaced84 in mysql_parse (thd=0x146088000c58, rawbuf=<optimized out>, length=<optimized out>, parser_state=<optimized out>) at /test/10.6_opt/sql/sql_parse.cc:8017

#8  0x00005623cbadad65 in dispatch_command (command=COM_QUERY, thd=0x146088000c58, packet=<optimized out>, packet_length=<optimized out>, blocking=<optimized out>) at /test/10.6_opt/sql/sql_class.h:1331

#9  0x00005623cbadccd7 in do_command (thd=0x146088000c58, blocking=blocking@entry=true) at /test/10.6_opt/sql/sql_parse.cc:1406

#10 0x00005623cbbdeeb7 in do_handle_one_connection (connect=<optimized out>, put_in_cache=true) at /test/10.6_opt/sql/sql_connect.cc:1410

#11 0x00005623cbbdf21d in handle_one_connection (arg=arg@entry=0x5623cf5fb0a8) at /test/10.6_opt/sql/sql_connect.cc:1312

#12 0x00005623cbf60439 in pfs_spawn_thread (arg=0x5623cf576f58) at /test/10.6_opt/storage/perfschema/pfs.cc:2201

#13 0x00001460e1a10609 in start_thread (arg=<optimized out>) at pthread_create.c:477

#14 0x00001460e15ff293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Core was generated by `/test/MD150421-mariadb-10.6.0-linux-x86_64-dbg/bin/mysqld --no-defaults --core-'.

Program terminated with signal SIGSEGV, Segmentation fault.

#0  0x000055d83c4a3a7d in Sys_var_sesvartrack::session_save_default (

    this=<optimized out>, thd=0x1530e4000db8, var=0x1530e4013ca8)

    at /test/10.6_dbg/sql/sys_vars.ic:677

677	     var->save_result.string_value.length=

[Current thread is 1 (Thread 0x153138163700 (LWP 225922))]

(gdb) bt

#0  0x000055d83c4a3a7d in Sys_var_sesvartrack::session_save_default (this=<optimized out>, thd=0x1530e4000db8, var=0x1530e4013ca8) at /test/10.6_dbg/sql/sys_vars.ic:677

#1  0x000055d83c2239c9 in sys_var::set_default (this=0x55d83d902c00 <Sys_track_session_sys_vars>, thd=0x1530e4000db8, var=0x1530e4013ca8) at /test/10.6_dbg/sql/set_var.cc:291

#2  0x000055d83c223a05 in set_var::update (this=<optimized out>, thd=<optimized out>) at /test/10.6_dbg/sql/set_var.cc:859

#3  0x000055d83c224d42 in sql_set_variables (thd=thd@entry=0x1530e4000db8, var_list=var_list@entry=0x1530e4005ec0, free=free@entry=true) at /test/10.6_dbg/sql/set_var.cc:746

#4  0x000055d83c32384c in mysql_execute_command (thd=thd@entry=0x1530e4000db8) at /test/10.6_dbg/sql/sql_parse.cc:5030

#5  0x000055d83c30ca06 in mysql_parse (thd=thd@entry=0x1530e4000db8, rawbuf=<optimized out>, length=<optimized out>, parser_state=parser_state@entry=0x153138162410) at /test/10.6_dbg/sql/sql_parse.cc:8017

#6  0x000055d83c31b7df in dispatch_command (command=command@entry=COM_QUERY, thd=thd@entry=0x1530e4000db8, packet=packet@entry=0x1530e400b369 "SET SESSION session_track_system_variables=DEFAULT", packet_length=packet_length@entry=50, blocking=blocking@entry=true) at /test/10.6_dbg/sql/sql_class.h:1331

#7  0x000055d83c31ebd5 in do_command (thd=0x1530e4000db8, blocking=blocking@entry=true) at /test/10.6_dbg/sql/sql_parse.cc:1406

#8  0x000055d83c47877c in do_handle_one_connection (connect=<optimized out>, connect@entry=0x55d83fb1a308, put_in_cache=put_in_cache@entry=true) at /test/10.6_dbg/sql/sql_connect.cc:1410

#9  0x000055d83c478d81 in handle_one_connection (arg=arg@entry=0x55d83fb1a308) at /test/10.6_dbg/sql/sql_connect.cc:1312

#10 0x000055d83c926a03 in pfs_spawn_thread (arg=0x55d83fa3eb48) at /test/10.6_dbg/storage/perfschema/pfs.cc:2201

#11 0x000015314d318609 in start_thread (arg=<optimized out>) at pthread_create.c:477

#12 0x000015314cf07293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95