Feedback-ID: i0fe9450f:Fastmail
Date: Wed, 13 May 2026 13:26:36 +0900
From: Michael Paquier <michael@paquier.xyz>
To: Andres Freund <andres@anarazel.de>
Cc: pgsql-hackers@lists.postgresql.org, Chao Li <li.evan.chao@gmail.com>
Subject: Re: Fix unsafe PlannedStmt access in pg_stat_statements
Message-ID: <agP9fFXriRN1HR5k@paquier.xyz>
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On Tue, May 12, 2026 at 11:00:16AM +0200, Andres Freund wrote:
> Seems like the code should make this clearer, by simply unsetting
> pstmt at the point it becomes unsafe to use?=20

Sure, we could do that as well and crash hard if something decides to
do the same mistake.  Like the simple patch attached for example?  I
am not sure if we need to update the comment.  It's pretty clear what
the intention is, at least to me.
--
Michael

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diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_s=
tat_statements/pg_stat_statements.c
index a2d3ab770cc6..92315627916d 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.c
+++ b/contrib/pg_stat_statements/pg_stat_statements.c
@@ -1175,6 +1175,7 @@ pgss_ProcessUtility(PlannedStmt *pstmt, const char *q=
ueryString,
 		 * For the same reason, we can't risk restoring pstmt->queryId to its
 		 * former value, which'd otherwise be a good idea.
 		 */
+		pstmt =3D NULL;
=20
 		INSTR_TIME_SET_CURRENT(duration);
 		INSTR_TIME_SUBTRACT(duration, start);

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