upstream/postgresql
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2026-02-23 01:40:33 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions
Base de données relationnelle
61833 commits 38 branches 674 tags 844 MiB
C 84.8%
PLpgSQL 6.1%
Perl 4.7%
Yacc 1.2%
Meson 0.7%
Other 2.4%
Find a file
Michael Paquier 3b3fa94900 Fix use-after-free with INSERT ON CONFLICT changes in reorderbuffer.c 
In ReorderBufferProcessTXN(), used to send the data of a transaction to
an output plugin, INSERT ON CONFLICT changes (INTERNAL_SPEC_INSERT) are
delayed until a confirmation record arrives (INTERNAL_SPEC_CONFIRM),
updating the change being processed.

8c58624df4 has added an extra step after processing a change to update
the progress of the transaction, by calling the callback
update_progress_txn() based on the LSN stored in a change after a
threshold of CHANGES_THRESHOLD (100) is reached.  This logic has missed
the fact that for an INSERT ON CONFLICT change the data is freed once
processed, hence update_progress_txn() could be called pointing to a LSN
value that's already been freed.  This could result in random crashes,
depending on the workload.

Per discussion, this issue is fixed by reusing in update_progress_txn()
the LSN from the change processed found at the beginning of the loop,
meaning that for a INTERNAL_SPEC_CONFIRM change the progress is updated
using the LSN of the INTERNAL_SPEC_CONFIRM change, and not the LSN from
its INTERNAL_SPEC_INSERT change.  This is actually more correct, as we
want to update the progress to point to the INTERNAL_SPEC_CONFIRM
change.

Masahiko Sawada has found a nice trick to reproduce the issue: hardcode
CHANGES_THRESHOLD at 1 and run test_decoding (test "ddl" being enough)
on an instance running valgrind.  The bug has been analyzed by Ethan
Mertz, who also originally suggested the solution used in this patch.

Issue introduced by 8c58624df4, so backpatch down to v16.

Author: Ethan Mertz <ethan.mertz@gmail.com>
Co-authored-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/aIsQqDZ7x4LAQ6u1@paquier.xyz
Backpatch-through: 16
2025-08-02 17:08:45 +09:00
.github Add CODE_OF_CONDUCT.md, CONTRIBUTING.md, and SECURITY.md. 2024-07-02 13:03:58 -05:00
config Don't put library-supplied -L/-I switches before user-supplied ones. 2025-07-29 15:17:40 -04:00
contrib Allow resetting unknown custom GUCs with reserved prefixes. 2025-08-01 16:52:11 -05:00
doc libpq: Complain about missing BackendKeyData later with PGgetCancel() 2025-08-01 18:24:19 +03:00
src Fix use-after-free with INSERT ON CONFLICT changes in reorderbuffer.c 2025-08-02 17:08:45 +09:00
.cirrus.star Remove duplicate words in docs and code comments. 2023-10-09 09:18:47 +05:30
.cirrus.tasks.yml Hide ICU C++ APIs from pg_locale.h 2025-07-09 14:20:22 +07:00
.cirrus.yml ci: Test NetBSD and OpenBSD 2025-02-12 09:40:07 -05:00
.dir-locals.el Make Emacs perl-mode indent more like perltidy. 2019-01-13 11:32:31 -08:00
.editorconfig Add script to keep .editorconfig in sync with .gitattributes 2025-02-01 10:09:45 +01:00
.git-blame-ignore-revs Add commit 1d1612aec7 to .git-blame-ignore-revs. 2025-07-29 10:32:53 -05:00
.gitattributes Add script to keep .editorconfig in sync with .gitattributes 2025-02-01 10:09:45 +01:00
.gitignore Update top-level .gitignore. 2022-12-04 15:23:00 -05:00
.mailmap Add a Git .mailmap file 2024-11-05 13:56:02 +01:00
aclocal.m4 autoconf: Move export_dynamic determination to configure 2022-12-06 18:55:28 -08:00
configure Fix ./configure checks with __cpuidex() and __cpuid() 2025-07-30 11:55:42 +09:00
configure.ac Fix ./configure checks with __cpuidex() and __cpuid() 2025-07-30 11:55:42 +09:00
COPYRIGHT Align organization wording in copyright statement 2025-05-16 11:20:07 -04:00
GNUmakefile.in Allow selecting the git revision to be packaged by "make dist". 2024-05-03 11:08:50 -04:00
HISTORY Canonicalize some URLs 2020-02-10 20:47:50 +01:00
Makefile Remove AIX support 2024-02-28 15:17:23 +04:00
meson.build Fix ./configure checks with __cpuidex() and __cpuid() 2025-07-30 11:55:42 +09:00
meson_options.txt Add support for basic NUMA awareness 2025-04-07 23:08:17 +02:00
README.md Revise the style of a paragraph in README.md. 2024-03-21 10:16:41 -05:00

README.md

PostgreSQL Database Management System

This directory contains the source code distribution of the PostgreSQL database management system.

PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.

Copyright and license information can be found in the file COPYRIGHT.

General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/devel/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/devel/installation.html.

The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.