Invalid memory address in doris::memory_copy

[worker24h]

Table Describe
CREATE TABLE tvad_funnel_pv (
window char(100) NOT NULL COMMENT "",
plat char(20) NOT NULL COMMENT "",
region char(10) NOT NULL COMMENT "",
position char(20) NOT NULL COMMENT "",
dt int(11) NOT NULL COMMENT "",
hr int(11) NOT NULL COMMENT "",
stock bigint(20) SUM NOT NULL COMMENT "",
consumer bigint(20) SUM NOT NULL COMMENT "",
exec bigint(20) SUM NOT NULL COMMENT ""
) ENGINE=OLAP
AGGREGATE KEY(window, plat, region, position, dt, hr)
COMMENT "OLAP"
PARTITION BY RANGE(dt)
(PARTITION p0 VALUES [("-2147483648"), ("20191220")),
PARTITION p20191220 VALUES [("20191220"), ("20191221")),
PARTITION p20191221 VALUES [("20191221"), ("20191222")),
PARTITION p20191222 VALUES [("20191222"), ("20191223")),
PARTITION p20191223 VALUES [("20191223"), ("20191224")),
PARTITION p20191224 VALUES [("20191224"), ("20191225")),
PARTITION p20191225 VALUES [("20191225"), ("20191226")))
DISTRIBUTED BY HASH(plat, region, video_id, bkg_id) BUCKETS 10
PROPERTIES (
"storage_type" = "COLUMN"
);

SQL
ALTER TABLE tvad_funnel_pv MODIFY COLUMN position varchar(20);

Describe the bug
When I change schema char(20) to varchar(20) cause coredump. The follow is backtrace：
(gdb) bt
#0 doris::memory_copy (dst=0xd21530c8, src=0x6d61726670617277, size=101)
at /home/doris-code/incubator-doris/be/src/util/mem_util.hpp:308
#1 0x0000000000e9dd04 in doris::FieldTypeTraits<(doris::FieldType)13>::deep_copy (dest=0xd981d7e4, src=0x101ebcca4,
mem_pool=) at /home/doris-code/incubator-doris/be/src/olap/types.h:541
#2 0x000000000153d712 in deep_copy (this=, mem_pool=0x9c2fcc0, src=, dest=)
at /home/doris-code/incubator-doris/be/src/olap/types.h:56
#3 deep_copy_content (this=, mem_pool=0x9c2fcc0, src=, dst=)
at /home/doris-code/incubator-doris/be/src/olap/field.h:189
#4 set_field_content (mem_pool=0x9c2fcc0, buf=, index=3, this=0x7f820f0dcf90)
at /home/doris-code/incubator-doris/be/src/olap/row_cursor.h:80
#5 doris::RowBlockChanger::change_row_block (this=this@entry=0x7f820f0dd200, ref_block=0x12cd915e0, data_version=,
mutable_block=mutable_block@entry=0x12cd903c0, filtered_rows=filtered_rows@entry=0x7f820f0dd070)
at /home/doris-code/incubator-doris/be/src/olap/schema_change.cpp:335
#6 0x0000000001540072 in doris::SchemaChangeDirectly::process (this=0x12c52ab40, rowset_reader=..., rowset_writer=0x1d43221b80,
new_tablet=..., base_tablet=...) at /home/doris-code/incubator-doris/be/src/olap/schema_change.cpp:793
#7 0x00000000015476c1 in doris::SchemaChangeHandler::_convert_historical_rowsets (sc_params=...)
at /home/doris-code/incubator-doris/be/src/olap/schema_change.cpp:1954
#8 0x0000000001549ab7 in doris::SchemaChangeHandler::_do_process_alter_tablet_v2 (this=this@entry=0x7f820f0dd580, request=...)
at /home/doris-code/incubator-doris/be/src/olap/schema_change.cpp:1337
#9 0x000000000154ab56 in doris::SchemaChangeHandler::process_alter_tablet_v2 (this=this@entry=0x7f820f0dd580, request=...)
at /home/doris-code/incubator-doris/be/src/olap/schema_change.cpp:1162
#10 0x000000000157fc39 in doris::EngineAlterTabletTask::execute (this=0x7f820f0dd7c0)
at /home/doris-code/incubator-doris/be/src/olap/task/engine_alter_tablet_task.cpp:39
#11 0x0000000000e45715 in doris::StorageEngine::execute_task (this=0x6192840, task=task@entry=0x7f820f0dd7c0)
at /home/doris-code/incubator-doris/be/src/olap/storage_engine.cpp:941
#12 0x0000000001391f0e in doris::TaskWorkerPool::_alter_tablet (this=this@entry=0x124ad200,
worker_pool_this=worker_pool_this@entry=0x124ad200, agent_task_req=..., signature=signature@entry=2457377,
task_type=doris::TTaskType::ALTER, finish_task_request=finish_task_request@entry=0x7f820f0dd890)
at /home/doris-code/incubator-doris/be/src/agent/task_worker_pool.cpp:635
#13 0x000000000139c3af in doris::TaskWorkerPool::_alter_tablet_worker_thread_callback (arg_this=0x124ad200)
at /home/doris-code/incubator-doris/be/src/agent/task_worker_pool.cpp:570
#14 0x00007f829f9b0dd5 in start_thread () from /lib64/libpthread.so.0
#15 0x00007f829fcc2ead in clone () from /lib64/libc.so.6