Description: PostgreSQL Server Subprocess Went down at function ‘pg_detoast_datum’
PostgreSQL Server Version: PostgreSQL 15.2 on x86_64-pc-linux-gnu, compiled by Ubuntu clang version 12.0.1, 64-bit
Discoverer: Jingzhou Fu, Jie Liang and Zhiyong Wu in WingTecher Lab of Tsinghua University and Shuimuyulin ltd
Email address: fjz22@mails.tsinghua.edu.cn , wuzy21@mails.tsinghua.edu.cn , ljiee@mail.tsinghua.edu.cn
Way to Reproduce with Docker (write the poc content into file PoC.sql):
```bash
docker container rm some-postgres -f
docker run --name some-postgres -p 5432:5432 -e POSTGRES_PASSWORD=mysecretpassword -d postgres:15.2
sleep 5 # wait the server start …
docker exec -i some-postgres psql --user=postgres < PoC.sql
# Output:
# server closed the connection unexpectedly
# This probably means the server terminated abnormally
# before or while processing the request.
# connection to server was lost
```
PoC:
```sql
create function parent(cstring) returns parent
strict immutable language internal as 'int8in';
create function a(parent) returns cstring
strict immutable language internal as 'int8out';
CREATE TYPE parent (
internallength = variable,
input = parent,
output = a,
alignment = int4
);
CREATE domain child as int not null check (value > 0);
create table grandchild (part int8 primary key, b child, c child);
explain (costs off)
select * from grandchild where part = part and part = '42'::parent;
```
Backtrace:
```
#0 0x1cc6f79 (pg_detoast_datum+0x49)
#1 0xaeeffc (coerce_type+0xc5c)
#2 0xaeda7e (coerce_to_target_type+0x41e)
#3 0xb1603f (transformTypeCast+0x63f)
#4 0xb10786 (transformExprRecurse+0x2f6)
#5 0xb170cf (transformAExprOp+0xa7f)
#6 0xb1081d (transformExprRecurse+0x38d)
#7 0xb1b8ad (transformBoolExpr+0x5ed)
#8 0xb109a5 (transformExprRecurse+0x515)
#9 0xb1042a (transformExpr+0xba)
#10 0xad56c6 (transformWhereClause+0x46)
#11 0xa2484e (transformSelectStmt+0x85e)
#12 0xa1c6ee (transformStmt+0x22e)
#13 0xa1cd10 (transformOptionalSelectInto+0x390)
#14 0xa2c931 (transformExplainStmt+0x51)
#15 0xa1c761 (transformStmt+0x2a1)
#16 0xa1cd10 (transformOptionalSelectInto+0x390)
#17 0xa1be4e (transformTopLevelStmt+0x4e)
#18 0xa1bd6b (parse_analyze_fixedparams+0xcb)
#19 0x16e14b7 (pg_analyze_and_rewrite_fixedparams+0x97)
#20 0x16e922a (exec_simple_query+0x99a)
#21 0x16e7a63 (PostgresMain+0x1523)
#22 0x144c17b (BackendRun+0xbb)
#23 0x144ad85 (BackendStartup+0x525)
#24 0x14481e6 (ServerLoop+0x616)
#25 0x1443e0f (PostmasterMain+0x30cf)
#26 0x106ebf2 (main+0x5a2)
#27 0x7f5bf768c083 (__libc_start_main+0xf3)
#28 0x49fc0e (_start+0x2e)
```
