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Date: Tue, 12 May 2026 11:00:16 +0200
From: Andres Freund <andres@anarazel.de>
To: pgsql-hackers@lists.postgresql.org, Michael Paquier <michael@paquier.xyz>,
 Chao Li <li.evan.chao@gmail.com>
CC: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Fix unsafe PlannedStmt access in pg_stat_statements
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Hi,=20

On May 12, 2026 5:30:53 AM GMT+02:00, Michael Paquier <michael@paquier=2Ex=
yz> wrote:
>On Mon, May 11, 2026 at 04:11:41PM +0800, Chao Li wrote:
>> On May 11, 2026, at 16:07, Chao Li <li=2Eevan=2Echao@gmail=2Ecom> wrote=
:
>>> In pgss_ProcessUtility(), there is this comment:
>>> ```
>>> /*
>>> * CAUTION: do not access the *pstmt data structure again below here=2E
>>> * If it was a ROLLBACK or similar, that data structure may have been
>>> * freed=2E  We must copy everything we still need into local variables=
,
>>> * which we did above=2E
>>> *
>>> * For the same reason, we can't risk restoring pstmt->queryId to its
>>> * former value, which'd otherwise be a good idea=2E
>>> */
>>> ```
>>>=20
>>> The attached patch fixes this by saving pstmt->planOrigin,
>>> following the same pattern already used for queryId, stmt_location,
>>> and stmt_len=2E
>
>Yeah, you are right=2E  This code should save the planOrigin but it does
>not do so=2E

Seems like the code should make this clearer, by simply unsetting pstmt at=
 the point it becomes unsafe to use?=20


Andres