From: Fujii Masao <fujii@postgresql.org>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Add guard to prevent recursive memory context logging.
Date: Fri, 19 Dec 2025 03:11:00 +0000
Message-ID: <E1vWQtP-001WpE-1M@gemulon.postgresql.org> (raw)
Add guard to prevent recursive memory context logging.
Previously, if memory context logging was triggered repeatedly and
rapidly while a previous request was still being processed, it could
result in recursive calls to ProcessLogMemoryContextInterrupt().
This could lead to infinite recursion and potentially crash the process.
This commit adds a guard to prevent such recursion.
If ProcessLogMemoryContextInterrupt() is already in progress and
logging memory contexts, subsequent calls will exit immediately,
avoiding unintended recursive calls.
While this scenario is unlikely in practice, it's not impossible.
This change adds a safety check to prevent such failures.
Back-patch to v14, where memory context logging was introduced.
Reported-by: Robert Haas <robertmhaas@gmail.com>
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Atsushi Torikoshi <torikoshia@oss.nttdata.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Artem Gavrilov <artem.gavrilov@percona.com>
Discussion: https://postgr.es/m/CA+TgmoZMrv32tbNRrFTvF9iWLnTGqbhYSLVcrHGuwZvCtph0NA@mail.gmail.com
Backpatch-through: 14
Branch
------
REL_16_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/3853f61681e850e846150b38cf9f5ebb34523740
Modified Files
--------------
src/backend/utils/mmgr/mcxt.c | 57 ++++++++++++++++++++++++++++++-------------
1 file changed, 40 insertions(+), 17 deletions(-)
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To: pgsql-committers@postgresql.org
Cc: fujii@postgresql.org, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Add guard to prevent recursive memory context logging.
In-Reply-To: <E1vWQtP-001WpE-1M@gemulon.postgresql.org>
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