Commit graph

46073 commits

Author SHA1 Message Date
Heikki Linnakangas
b08033944e Make pg_numa_query_pages() work in frontend programs
It's currently only used in the server, but it was placed in src/port
with the idea that it might be useful in client programs too. However,
it will currently fail to link if used in a client program, because
CHECK_FOR_INTERRUPTS() is not usable in client programs. Fix that by
wrapping it in "#ifndef FRONTEND".

Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Discussion: https://www.postgresql.org/message-id/21cc7a48-99d9-4f69-9a3f-2c2de61ac8e5%40iki.fi
Backpatch-through: 18
2026-02-12 19:41:29 +02:00
Tom Lane
ce4b7e3a10 Fix plpgsql's handling of "return simple_record_variable".
If the variable's value is null, exec_stmt_return() missed filling
in estate->rettype.  This is a pretty old bug, but we'd managed not
to notice because that value isn't consulted for a null result ...
unless we have to cast it to a domain.  That case led to a failure
with "cache lookup failed for type 0".

The correct way to assign the data type is known by exec_eval_datum.
While we could copy-and-paste that logic, it seems like a better
idea to just invoke exec_eval_datum, as the ROW case already does.

Reported-by: Pavel Stehule <pavel.stehule@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAFj8pRBT_ahexDf-zT-cyH8bMR_qcySKM8D5nv5MvTWPiatYGA@mail.gmail.com
Backpatch-through: 14
2026-02-11 16:53:14 -05:00
Heikki Linnakangas
53463b4b24 Fix pg_stat_get_backend_wait_event() for aux processes
The pg_stat_activity view shows information for aux processes, but the
pg_stat_get_backend_wait_event() and
pg_stat_get_backend_wait_event_type() functions did not. To fix, call
AuxiliaryPidGetProc(pid) if BackendPidGetProc(pid) returns NULL, like
we do in pg_stat_get_activity().

In version 17 and above, it's a little silly to use those functions
when we already have the ProcNumber at hand, but it was necessary
before v17 because the backend ID was different from ProcNumber. I
have other plans for wait_event_info on master, so it doesn't seem
worth applying a different fix on different versions now.

Reviewed-by: Sami Imseih <samimseih@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://www.postgresql.org/message-id/c0320e04-6e85-4c49-80c5-27cfb3a58108@iki.fi
Backpatch-through: 14
2026-02-11 18:51:06 +02:00
Tom Lane
b69af3dda2 Harden _int_matchsel() against being attached to the wrong operator.
While the preceding commit prevented such attachments from occurring
in future, this one aims to prevent further abuse of any already-
created operator that exposes _int_matchsel to the wrong data types.
(No other contrib module has a vulnerable selectivity estimator.)

We need only check that the Const we've found in the query is indeed
of the type we expect (query_int), but there's a difficulty: as an
extension type, query_int doesn't have a fixed OID that we could
hard-code into the estimator.

Therefore, the bulk of this patch consists of infrastructure to let
an extension function securely look up the OID of a datatype
belonging to the same extension.  (Extension authors have requested
such functionality before, so we anticipate that this code will
have additional non-security uses, and may soon be extended to allow
looking up other kinds of SQL objects.)

This is done by first finding the extension that owns the calling
function (there can be only one), and then thumbing through the
objects owned by that extension to find a type that has the desired
name.  This is relatively expensive, especially for large extensions,
so a simple cache is put in front of these lookups.

Reported-by: Daniel Firer as part of zeroday.cloud
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Noah Misch <noah@leadboat.com>
Security: CVE-2026-2004
Backpatch-through: 14
2026-02-09 10:14:22 -05:00
Tom Lane
66ddac6982 Require superuser to install a non-built-in selectivity estimator.
Selectivity estimators come in two flavors: those that make specific
assumptions about the data types they are working with, and those
that don't.  Most of the built-in estimators are of the latter kind
and are meant to be safely attachable to any operator.  If the
operator does not behave as the estimator expects, you might get a
poor estimate, but it won't crash.

However, estimators that do make datatype assumptions can malfunction
if they are attached to the wrong operator, since then the data they
get from pg_statistic may not be of the type they expect.  This can
rise to the level of a security problem, even permitting arbitrary
code execution by a user who has the ability to create SQL objects.

To close this hole, establish a rule that built-in estimators are
required to protect themselves against being called on the wrong type
of data.  It does not seem practical however to expect estimators in
extensions to reach a similar level of security, at least not in the
near term.  Therefore, also establish a rule that superuser privilege
is required to attach a non-built-in estimator to an operator.
We expect that this restriction will have little negative impact on
extensions, since estimators generally have to be written in C and
thus superuser privilege is required to create them in the first
place.

This commit changes the privilege checks in CREATE/ALTER OPERATOR
to enforce the rule about superuser privilege, and fixes a couple
of built-in estimators that were making datatype assumptions without
sufficiently checking that they're valid.

Reported-by: Daniel Firer as part of zeroday.cloud
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Noah Misch <noah@leadboat.com>
Security: CVE-2026-2004
Backpatch-through: 14
2026-02-09 10:07:31 -05:00
Tom Lane
3b6588cd90 Guard against unexpected dimensions of oidvector/int2vector.
These data types are represented like full-fledged arrays, but
functions that deal specifically with these types assume that the
array is 1-dimensional and contains no nulls.  However, there are
cast pathways that allow general oid[] or int2[] arrays to be cast
to these types, allowing these expectations to be violated.  This
can be exploited to cause server memory disclosure or SIGSEGV.
Fix by installing explicit checks in functions that accept these
types.

Reported-by: Altan Birler <altan.birler@tum.de>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Noah Misch <noah@leadboat.com>
Security: CVE-2026-2003
Backpatch-through: 14
2026-02-09 09:57:44 -05:00
Thomas Munro
b0f5d25bc3 Code coverage for most pg_mblen* calls.
A security patch changed them today, so close the coverage gap now.
Test that buffer overrun is avoided when pg_mblen*() requires more
than the number of bytes remaining.

This does not cover the calls in dict_thesaurus.c or in dict_synonym.c.
That code is straightforward.  To change that code's input, one must
have access to modify installed OS files, so low-privilege users are not
a threat.  Testing this would likewise require changing installed
share/postgresql/tsearch_data, which was enough of an obstacle to not
bother.

Security: CVE-2026-2006
Backpatch-through: 14
Co-authored-by: Thomas Munro <thomas.munro@gmail.com>
Co-authored-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
2026-02-09 12:43:50 +13:00
Thomas Munro
7b5fc85bef Replace pg_mblen() with bounds-checked versions.
A corrupted string could cause code that iterates with pg_mblen() to
overrun its buffer.  Fix, by converting all callers to one of the
following:

1. Callers with a null-terminated string now use pg_mblen_cstr(), which
raises an "illegal byte sequence" error if it finds a terminator in the
middle of the sequence.

2. Callers with a length or end pointer now use either
pg_mblen_with_len() or pg_mblen_range(), for the same effect, depending
on which of the two seems more convenient at each site.

3. A small number of cases pre-validate a string, and can use
pg_mblen_unbounded().

The traditional pg_mblen() function and COPYCHAR macro still exist for
backward compatibility, but are no longer used by core code and are
hereby deprecated.  The same applies to the t_isXXX() functions.

Security: CVE-2026-2006
Backpatch-through: 14
Co-authored-by: Thomas Munro <thomas.munro@gmail.com>
Co-authored-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reported-by: Paul Gerste (as part of zeroday.cloud)
Reported-by: Moritz Sanft (as part of zeroday.cloud)
2026-02-09 12:43:42 +13:00
Thomas Munro
efef05ba99 Fix mb2wchar functions on short input.
When converting multibyte to pg_wchar, the UTF-8 implementation would
silently ignore an incomplete final character, while the other
implementations would cast a single byte to pg_wchar, and then repeat
for the remaining byte sequence.  While it didn't overrun the buffer, it
was surely garbage output.

Make all encodings behave like the UTF-8 implementation.  A later change
for master only will convert this to an error, but we choose not to
back-patch that behavior change on the off-chance that someone is
relying on the existing UTF-8 behavior.

Security: CVE-2026-2006
Backpatch-through: 14
Author: Thomas Munro <thomas.munro@gmail.com>
Reported-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
2026-02-09 12:12:33 +13:00
Thomas Munro
df0852fe03 Fix encoding length for EUC_CN.
While EUC_CN supports only 1- and 2-byte sequences (CS0, CS1), the
mb<->wchar conversion functions allow 3-byte sequences beginning SS2,
SS3.

Change pg_encoding_max_length() to return 3, not 2, to close a
hypothesized buffer overrun if a corrupted string is converted to wchar
and back again in a newly allocated buffer.  We might reconsider that in
master (ie harmonizing in a different direction), but this change seems
better for the back-branches.

Also change pg_euccn_mblen() to report SS2 and SS3 characters as having
length 3 (following the example of EUC_KR).  Even though such characters
would not pass verification, it's remotely possible that invalid bytes
could be used to compute a buffer size for use in wchar conversion.

Security: CVE-2026-2006
Backpatch-through: 14
Author: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
2026-02-09 12:12:29 +13:00
Heikki Linnakangas
e0965fb1a8 Fix buffer overflows in pg_trgm due to lower-casing
The code made a subtle assumption that the lower-cased version of a
string never has more characters than the original. That is not always
true. For example, in a database with the latin9 encoding:

    latin9db=# select lower(U&'\00CC' COLLATE "lt-x-icu");
       lower
    -----------
     i\x1A\x1A
    (1 row)

In this example, lower-casing expands the single input character into
three characters.

The generate_trgm_only() function relied on that assumption in two
ways:

- It used "slen * pg_database_encoding_max_length() + 4" to allocate
  the buffer to hold the lowercased and blank-padded string. That
  formula accounts for expansion if the lower-case characters are
  longer (in bytes) than the originals, but it's still not enough if
  the lower-cased string contains more *characters* than the original.

- Its callers sized the output array to hold the trigrams extracted
  from the input string with the formula "(slen / 2 + 1) * 3", where
  'slen' is the input string length in bytes. (The formula was
  generous to account for the possibility that RPADDING was set to 2.)
  That's also not enough if one input byte can turn into multiple
  characters.

To fix, introduce a growable trigram array and give up on trying to
choose the correct max buffer sizes ahead of time.

Backpatch to v18, but no further. In previous versions lower-casing was
done character by character, and thus the assumption that lower-casing
doesn't change the character length was valid. That was changed in v18,
commit fb1a18810f.

Security: CVE-2026-2007
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Jeff Davis <pgsql@j-davis.com>
2026-02-09 12:12:24 +13:00
Peter Eisentraut
731e03272e Translation updates
Source-Git-URL: https://git.postgresql.org/git/pgtranslation/messages.git
Source-Git-Hash: bdee668bac7ab3256b6f922c0b6fb663a3b03e16
2026-02-08 15:07:02 +01:00
Peter Eisentraut
cff2ef9845 Further error message fix
Further fix of error message changed in commit 74a116a79b.  The
initial fix was not quite correct.

Discussion: https://www.postgresql.org/message-id/flat/tencent_1EE1430B1E6C18A663B8990F%40qq.com
2026-02-07 22:53:16 +01:00
Michael Paquier
e679d0f0b6 Fix use of proc number in pgstat_create_backend()
This routine's internals directly used MyProcNumber to choose which
object ID to assign for the hash key of a backend's stats entry, while
the value to use is given as input argument of the function.

The original intention was to pass MyProcNumber as an argument of
pgstat_create_backend() when called in pgstat_bestart_final(),
pgstat_beinit() ensuring that MyProcNumber has been set, not use it
directly in the function.  This commit addresses this inconsistency by
using the procnum given by the caller of pgstat_create_backend(), not
MyProcNumber.

This issue is not a cause of bugs currently.  However, let's keep the
code in sync across all the branches where this code exists, as it could
matter in a future backpatch.

Oversight in 4feba03d8b.

Reported-by: Ryo Matsumura <matsumura.ryo@fujitsu.com>
Discussion: https://postgr.es/m/TYCPR01MB11316AD8150C8F470319ACCAEE866A@TYCPR01MB11316.jpnprd01.prod.outlook.com
Backpatch-through: 18
2026-02-06 19:57:26 +09:00
Michael Paquier
acfa422c3c Fix some error message inconsistencies
These errors are very unlikely going to show up, but in the event that
they happen, some incorrect information would have been provided:
- In pg_rewind, a stat() failure was reported as an open() failure.
- In pg_combinebackup, a check for the new directory of a tablespace
mapping was referred as the old directory.
- In pg_combinebackup, a failure in reading a source file when copying
blocks referred to the destination file.

The changes for pg_combinebackup affect v17 and newer versions.  For
pg_rewind, all the stable branches are affected.

Author: Man Zeng <zengman@halodbtech.com>
Discussion: https://postgr.es/m/tencent_1EE1430B1E6C18A663B8990F@qq.com
Backpatch-through: 14
2026-02-06 15:38:21 +09:00
Thomas Munro
33e3de6d77 Add file_extend_method=posix_fallocate,write_zeros.
Provide a way to disable the use of posix_fallocate() for relation
files.  It was introduced by commit 4d330a61bb.  The new setting
file_extend_method=write_zeros can be used as a workaround for problems
reported from the field:

 * BTRFS compression is disabled by the use of posix_fallocate()
 * XFS could produce spurious ENOSPC errors in some Linux kernel
   versions, though that problem is reported to have been fixed

The default is file_extend_method=posix_fallocate if available, as
before.  The write_zeros option is similar to PostgreSQL < 16, except
that now it's multi-block.

Backpatch-through: 16
Reviewed-by: Jakub Wartak <jakub.wartak@enterprisedb.com>
Reported-by: Dimitrios Apostolou <jimis@gmx.net>
Discussion: https://postgr.es/m/b1843124-fd22-e279-a31f-252dffb6fbf2%40gmx.net
2026-02-06 17:38:39 +13:00
Fujii Masao
8eb17e82fc Fix logical replication TAP test to read publisher log correctly.
Commit 5f13999aa1 added a TAP test for GUC settings passed via the
CONNECTION string in logical replication, but the buildfarm member
sungazer reported test failures.

The test incorrectly used the subscriber's log file position as the
starting offset when reading the publisher's log. As a result, the test
failed to find the expected log message in the publisher's log and
erroneously reported a failure.

This commit fixes the test to use the publisher's own log file position
when reading the publisher's log.

Also, to avoid similar confusion in the future, this commit splits the single
$log_location variable into $log_location_pub and $log_location_sub,
clearly distinguishing publisher and subscriber log positions.

Backpatched to v15, where commit 5f13999aa1 introduced the test.

Per buildfarm member sungazer.
This issue was reported and diagnosed by Alexander Lakhin.

Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/966ec3d8-1b6f-4f57-ae59-fc7d55bc9a5a@gmail.com
Backpatch-through: 15
2026-02-05 00:46:09 +09:00
John Naylor
b5e1cd2fdc Fix various instances of undefined behavior
Mostly this involves checking for NULL pointer before doing operations
that add a non-zero offset.

The exception is an overflow warning in heap_fetch_toast_slice(). This
was caused by unneeded parentheses forcing an expression to be
evaluated to a negative integer, which then got cast to size_t.

Per clang 21 undefined behavior sanitizer.

Backpatch to all supported versions.

Co-authored-by: Alexander Lakhin <exclusion@gmail.com>
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/777bd201-6e3a-4da0-a922-4ea9de46a3ee@gmail.com
Backpatch-through: 14
2026-02-04 17:59:18 +07:00
Michael Paquier
2ca4464b69 pg_resetwal: Fix incorrect error message related to pg_wal/summaries/
A failure while closing pg_wal/summaries/ incorrectly generated a report
about pg_wal/archive_status/.

While at it, this commit adds #undefs for the macros used in
KillExistingWALSummaries() and KillExistingArchiveStatus() to prevent
those values from being misused in an incorrect function context.

Oversight in dc21234005.

Author: Tianchen Zhang <zhang_tian_chen@163.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/SE2P216MB2390C84C23F428A7864EE07FA19BA@SE2P216MB2390.KORP216.PROD.OUTLOOK.COM
Backpatch-through: 17
2026-02-04 16:38:10 +09:00
Álvaro Herrera
492a69e140
Reject ADD CONSTRAINT NOT NULL if name mismatches existing constraint
When using ALTER TABLE ... ADD CONSTRAINT to add a not-null constraint
with an explicit name, we have to ensure that if the column is already
marked NOT NULL, the provided name matches the existing constraint name.
Failing to do so could lead to confusion regarding which constraint
object actually enforces the rule.

This patch adds a check to throw an error if the user tries to add a
named not-null constraint to a column that already has one with a
different name.

Reported-by: yanliang lei <msdnchina@163.com>
Co-authored-by: Álvaro Herrera <alvherre@kurilemu.de>
Co-authored-bu: Srinath Reddy Sadipiralla <srinath2133@gmail.com>
Backpatch-through: 18
Discussion: https://postgr.es/m/19351-8f1c523ead498545%40postgresql.org
2026-02-03 12:33:29 +01:00
Michael Paquier
719aa13b58 Fix incorrect errno in OpenWalSummaryFile()
This routine has an option to bypass an error if a WAL summary file is
opened for read but is missing (missing_ok=true).  However, the code
incorrectly checked for EEXIST, that matters when using O_CREAT and
O_EXCL, rather than ENOENT, for this case.

There are currently only two callers of OpenWalSummaryFile() in the
tree, and both use missing_ok=false, meaning that the check based on the
errno is currently dead code.  This issue could matter for out-of-core
code or future backpatches that would like to use missing_ok set to
true.

Issue spotted while monitoring this area of the code, after
a9afa021e9.

Author: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/aYAf8qDHbpBZ3Rml@paquier.xyz
Backpatch-through: 17
2026-02-03 11:25:14 +09:00
Michael Paquier
ab61f00874 Fix error message in RemoveWalSummaryIfOlderThan()
A failing unlink() was reporting an incorrect error message, referring
to stat().

Author: Man Zeng <zengman@halodbtech.com>
Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Discussion: https://postgr.es/m/tencent_3BBE865C5F49D452360FF190@qq.com
Backpath-through: 17
2026-02-02 10:21:07 +09:00
Michael Paquier
d5a4856ffe Fix build inconsistency due to the generation of wait-event code
The build generates four files based on the wait event contents stored
in wait_event_names.txt:
- wait_event_types.h
- pgstat_wait_event.c
- wait_event_funcs_data.c
- wait_event_types.sgml

The SGML file is generated as part of a documentation build, with its
data stored in doc/src/sgml/ for meson and configure.  The three others
are handled differently for meson and configure:
- In configure, all the files are created in src/backend/utils/activity/.
A link to wait_event_types.h is created in src/include/utils/.
- In meson, all the files are created in src/include/utils/.

The two C files, pgstat_wait_event.c and wait_event_funcs_data.c, are
then included in respectively wait_event.c and wait_event_funcs.c,
without the "utils/" path.

For configure, this does not present a problem.  For meson, this has to
be combined with a trick in src/backend/utils/activity/meson.build,
where include_directories needs to point to include/utils/ to make the
inclusion of the C files work properly, causing builds to pull in
PostgreSQL headers rather than system headers in some build paths, as
src/include/utils/ would take priority.

In order to fix this issue, this commit reworks the way the C/H files
are generated, becoming consistent with guc_tables.inc.c:
- For meson, basically nothing changes.  The files are still generated
in src/include/utils/.  The trick with include_directories is removed.
- For configure, the files are now generated in src/backend/utils/, with
links in src/include/utils/ pointing to the ones in src/backend/.  This
requires extra rules in src/backend/utils/activity/Makefile so as a
make command in this sub-directory is able to work.
- The three files now fall under header-stamp, which is actually simpler
as guc_tables.inc.c does the same.
- wait_event_funcs_data.c and pgstat_wait_event.c are now included with
"utils/" in their path.

This problem has not been an issue in the buildfarm; it has been noted
with AIX and a conflict with float.h.  This issue could, however, create
conflicts in the buildfarm depending on the environment with unexpected
headers pulled in, so this fix is backpatched down to where the
generation of the wait-event files has been introduced.

While on it, this commit simplifies wait_event_names.txt regarding the
paths of the files generated, to mention just the names of the files
generated.  The paths where the files are generated became incorrect.
The path of the SGML path was wrong.

This change has been tested in the CI, down to v17.  Locally, I have run
tests with configure (with and without VPATH), as well as meson, on the
three branches.

Combo oversight in fa88928470 and 1e68e43d3f.

Reported-by: Aditya Kamath <aditya.kamath1@ibm.com>
Discussion: https://postgr.es/m/LV8PR15MB64888765A43D229EA5D1CFE6D691A@LV8PR15MB6488.namprd15.prod.outlook.com
Backpatch-through: 17
2026-02-02 08:02:59 +09:00
Tom Lane
92b3cc5a28 Improve guards against false regex matches in BackgroundPsql.pm.
BackgroundPsql needs to wait for all the output from an interactive
psql command to come back.  To make sure that's happened, it issues
the command, then issues \echo and \warn psql commands that echo
a "banner" string (which we assume won't appear in the command's
output), then waits for the banner strings to appear.  The hazard
in this approach is that the banner will also appear in the echoed
psql commands themselves, so we need to distinguish those echoes from
the desired output.  Commit 8b886a4e3 tried to do that by positing
that the desired output would be directly preceded and followed by
newlines, but it turns out that that assumption is timing-sensitive.
In particular, it tends to fail in builds made --without-readline,
wherein the command echoes will be made by the pty driver and may
be interspersed with prompts issued by psql proper.

It does seem safe to assume that the banner output we want will be
followed by a newline, since that should be the last output before
things quiesce.  Therefore, we can improve matters by putting quotes
around the banner strings in the \echo and \warn psql commands, so
that their echoes cannot include banner directly followed by newline,
and then checking for just banner-and-newline in the match pattern.

While at it, spruce up the pump() call in sub query() to look like
the neater version in wait_connect(), and don't die on timeout
until after printing whatever we got.

Reported-by: Oleg Tselebrovskiy <o.tselebrovskiy@postgrespro.ru>
Diagnosed-by: Oleg Tselebrovskiy <o.tselebrovskiy@postgrespro.ru>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Soumya S Murali <soumyamurali.work@gmail.com>
Discussion: https://postgr.es/m/db6fdb35a8665ad3c18be01181d44b31@postgrespro.ru
Backpatch-through: 14
2026-01-30 14:59:25 -05:00
Jeff Davis
09d8c35174 Fix theoretical memory leaks in pg_locale_libc.c.
The leaks were hard to reach in practice and the impact was low.

The callers provide a buffer the same number of bytes as the source
string (plus one for NUL terminator) as a starting size, and libc
never increases the number of characters. But, if the byte length of
one of the converted characters is larger, then it might need a larger
destination buffer. Previously, in that case, the working buffers
would be leaked.

Even in that case, the call typically happens within a context that
will soon be reset. Regardless, it's worth fixing to avoid such
assumptions, and the fix is simple so it's worth backporting.

Discussion: https://postgr.es/m/e2b7a0a88aaadded7e2d19f42d5ab03c9e182ad8.camel@j-davis.com
Backpatch-through: 18
2026-01-29 10:25:35 -08:00
Michael Paquier
d42735b1e8 psql: Disable %P (pipeline status) for non-active connection
In the psql prompt, %P prompt shows the current pipeline status.  Unlike
most of the other options, its status was showing up in the output
generated even if psql was not connected to a database.  This was
confusing, because without a connection a pipeline status makes no
sense.

Like the other options, %P is updated so as its data is now hidden
without an active connection.

Author: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/86EF76B5-6E62-404D-B9EC-66F4714D7D5F@gmail.com
Backpatch-through: 18
2026-01-29 16:20:50 +09:00
Amit Kapila
1c60f72363 Fix CI failure introduced in commit 851f6649cc.
The test added in commit 851f6649cc uses a backup taken from a node
created by the previous test to perform standby related checks. On
Windows, however, the standby failed to start with the following error:
FATAL:  could not rename file "backup_label" to "backup_label.old": Permission denied

This occurred because some background sessions from the earlier test were
still active. These leftover processes continued accessing the parent
directory of the backup_label file, likely preventing the rename and
causing the failure. Ensuring that these sessions are cleanly terminated
resolves the issue in local testing.

Additionally, the has_restoring => 1 option has been removed, as it was
not required by the new test.

Reported-by: Robert Haas <robertmhaas@gmail.com>
Backpatch-through: 17
Discussion: https://postgr.es/m/CA+TgmobdVhO0ckZfsBZ0wqDO4qHVCwZZx8sf=EinafvUam-dsQ@mail.gmail.com
2026-01-29 03:34:55 +00:00
Jacob Champion
444826b6dc oauth: Correct test dependency on oauth_hook_client
The oauth_validator tests missed the lessons of c89525d57 et al, so
certain combinations of command-line build order and `meson test`
options can result in

    Command 'oauth_hook_client' not found in [...] at src/test/perl/PostgreSQL/Test/Utils.pm line 427.

Add the missing dependency on the test executable. This fixes, for
example,

    $ ninja clean && ninja meson-test-prereq && PG_TEST_EXTRA=oauth meson test --no-rebuild

Reported-by: Jonathan Gonzalez V. <jonathan.abdiel@gmail.com>
Author: Jonathan Gonzalez V. <jonathan.abdiel@gmail.com>
Discussion: https://postgr.es/m/6e8f4f7c23faf77c4b6564c4b7dc5d3de64aa491.camel@gmail.com
Discussion: https://postgr.es/m/qh4c5tvkgjef7jikjig56rclbcdrrotngnwpycukd2n3k25zi2%4044hxxvtwmgum
Backpatch-through: 18
2026-01-27 11:58:26 -08:00
Amit Kapila
919c9fa13c Prevent invalidation of newly synced replication slots.
A race condition could cause a newly synced replication slot to become
invalidated between its initial sync and the checkpoint.

When syncing a replication slot to a standby, the slot's initial
restart_lsn is taken from the publisher's remote_restart_lsn. Because slot
sync happens asynchronously, this value can lag behind the standby's
current redo pointer. Without any interlocking between WAL reservation and
checkpoints, a checkpoint may remove WAL required by the newly synced
slot, causing the slot to be invalidated.

To fix this, we acquire ReplicationSlotAllocationLock before reserving WAL
for a newly synced slot, similar to commit 006dd4b2e5. This ensures that
if WAL reservation happens first, the checkpoint process must wait for
slotsync to update the slot's restart_lsn before it computes the minimum
required LSN.

However, unlike in ReplicationSlotReserveWal(), this lock alone cannot
protect a newly synced slot if a checkpoint has already run
CheckPointReplicationSlots() before slotsync updates the slot. In such
cases, the remote restart_lsn may be stale and earlier than the current
redo pointer. To prevent relying on an outdated LSN, we use the oldest
WAL location available if it is greater than the remote restart_lsn.

This ensures that newly synced slots always start with a safe, non-stale
restart_lsn and are not invalidated by concurrent checkpoints.

Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Vitaly Davydov <v.davydov@postgrespro.ru>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Backpatch-through: 17
Discussion: https://postgr.es/m/TY4PR01MB16907E744589B1AB2EE89A31F94D7A%40TY4PR01MB16907.jpnprd01.prod.outlook.com
2026-01-27 05:45:25 +00:00
Tomas Vondra
9796c4f560 Handle ENOENT status when querying NUMA node
We've assumed that touching the memory is sufficient for a page to be
located on one of the NUMA nodes. But a page may be moved to a swap
after we touch it, due to memory pressure.

We touch the memory before querying the status, but there is no
guarantee it won't be moved to the swap in the meantime. The touching
happens only on the first call, so later calls are more likely to be
affected. And the batching increases the window too.

It's up to the kernel if/when pages get moved to swap. We have to accept
ENOENT (-2) as a valid result, and handle it without failing. This patch
simply treats it as an unknown node, and returns NULL in the two
affected views (pg_shmem_allocations_numa and pg_buffercache_numa).

Hugepages cannot be swapped out, so this affects only regular pages.

Reported by Christoph Berg, investigation and fix by me. Backpatch to
18, where the two views were introduced.

Reported-by: Christoph Berg <myon@debian.org>
Discussion: 18
Backpatch-through: https://postgr.es/m/aTq5Gt_n-oS_QSpL@msg.df7cb.de
2026-01-26 23:37:03 +01:00
Tomas Vondra
32593394ee Exercise parallel GIN builds in regression tests
Modify two places creating GIN indexes in regression tests, so that the
build is parallel. This provides a basic test coverage, even if the
amounts of data are fairly small.

Reported-by: Kirill Reshke <reshkekirill@gmail.com>
Backpatch-through: 18
Discussion: https://postgr.es/m/CALdSSPjUprTj+vYp1tRKWkcLYzdy=N=O4Cn4y_HoxNSqQwBttg@mail.gmail.com
2026-01-26 20:05:00 +01:00
Tomas Vondra
eee71a66cc Lookup the correct ordering for parallel GIN builds
When building a tuplesort during parallel GIN builds, the function
incorrectly looked up the default B-Tree operator, not the function
associated with the GIN opclass (through GIN_COMPARE_PROC).

Fixed by using the same logic as initGinState(), and the other place
in parallel GIN builds.

This could cause two types of issues. First, a data type might not have
a B-Tree opclass, in which case the PrepareSortSupportFromOrderingOp()
fails with an ERROR. Second, a data type might have both B-Tree and GIN
opclasses, defining order/equality in different ways. This could lead to
logical corruption in the index.

Backpatch to 18, where parallel GIN builds were introduced.

Discussion: https://postgr.es/m/73a28b94-43d5-4f77-b26e-0d642f6de777@iki.fi
Reported-by: Heikki Linnakangas <hlinnaka@iki.fi>
Backpatch-through: 18
2026-01-26 20:05:00 +01:00
Robert Haas
7903377d9d Reduce length of TAP test file name.
Buildfarm member fairywren hit the Windows limitation on the length of a
file path. While there may be other things we should also do to prevent
this from happening, it's certainly the case that the length of this
test file name is much longer than others in the same directory, so make
it shorter.

Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: http://postgr.es/m/274e0a1a-d7d2-4bc8-8b56-dd09f285715e@gmail.com
Backpatch-through: 17
2026-01-26 12:44:07 -05:00
David Rowley
ccde5be686 Fix possible issue of a WindowFunc being in the wrong WindowClause
ed1a88dda made it so WindowClauses can be merged when all window
functions belonging to the WindowClause can equally well use some
other WindowClause without any behavioral changes.  When that
optimization applies, the WindowFunc's "winref" gets adjusted to
reference the new WindowClause.

That commit does not work well with the deduplication logic in
find_window_functions(), which only added the WindowFunc to the list
when there wasn't already an identical WindowFunc in the list.  That
deduplication logic meant that the duplicate WindowFunc wouldn't get the
"winref" changed when optimize_window_clauses() was able to swap the
WindowFunc to another WindowClause.  This could lead to the following
error in the unlikely event that the deduplication code did something and
the duplicate WindowFunc happened to be moved into another WindowClause.

ERROR:  WindowFunc with winref 2 assigned to WindowAgg with winref 1

As it turns out, the deduplication logic in find_window_functions() is
pretty bogus.  It might have done something when added, as that code
predates b8d7f053c, which changed how projections work.  As it turns
out, at least now we *will* evaluate the duplicate WindowFuncs.  All
that the deduplication code seems to do today is assist in
underestimating the WindowAggPath costs due to not counting the
evaluation costs of duplicate WindowFuncs.

Ideally the fix would be to remove the deduplication code, but that
could result in changes to the plan costs, as duplicate WindowFuncs
would then be costed.  Instead, let's play it safe and shift the
deduplication code so it runs after the other processing in
optimize_window_clauses().

Backpatch only as far as v16 as there doesn't seem to be any other harm
done by the WindowFunc deduplication code before then.  This issue was
fixed in master by 7027dd499.

Reported-by: Meng Zhang <mza117jc@gmail.com>
Author: Meng Zhang <mza117jc@gmail.com>
Author: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/CAErYLFAuxmW0UVdgrz7iiuNrxGQnFK_OP9hBD5CUzRgjrVrz=Q@mail.gmail.com
Backpatch-through: 16
2026-01-26 23:46:23 +13:00
Dean Rasheed
c6ce4dcf9d Fix trigger transition table capture for MERGE in CTE queries.
When executing a data-modifying CTE query containing MERGE and some
other DML operation on a table with statement-level AFTER triggers,
the transition tables passed to the triggers would fail to include the
rows affected by the MERGE.

The reason is that, when initializing a ModifyTable node for MERGE,
MakeTransitionCaptureState() would create a TransitionCaptureState
structure with a single "tcs_private" field pointing to an
AfterTriggersTableData structure with cmdType == CMD_MERGE. Tuples
captured there would then not be included in the sets of tuples
captured when executing INSERT/UPDATE/DELETE ModifyTable nodes in the
same query.

Since there are no MERGE triggers, we should only create
AfterTriggersTableData structures for INSERT/UPDATE/DELETE. Individual
MERGE actions should then use those, thereby sharing the same capture
tuplestores as any other DML commands executed in the same query.

This requires changing the TransitionCaptureState structure, replacing
"tcs_private" with 3 separate pointers to AfterTriggersTableData
structures, one for each of INSERT, UPDATE, and DELETE. Nominally,
this is an ABI break to a public structure in commands/trigger.h.
However, since this is a private field pointing to an opaque data
structure, the only way to create a valid TransitionCaptureState is by
calling MakeTransitionCaptureState(), and no extensions appear to be
doing that anyway, so it seems safe for back-patching.

Backpatch to v15, where MERGE was introduced.

Bug: #19380
Reported-by: Daniel Woelfel <dwwoelfel@gmail.com>
Author: Dean Rasheed <dean.a.rasheed@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19380-4e293be2b4007248%40postgresql.org
Backpatch-through: 15
2026-01-24 11:30:48 +00:00
Amit Langote
9f4b7bfc5e Fix bogus ctid requirement for dummy-root partitioned targets
ExecInitModifyTable() unconditionally required a ctid junk column even
when the target was a partitioned table. This led to spurious "could
not find junk ctid column" errors when all children were excluded and
only the dummy root result relation remained.

A partitioned table only appears in the result relations list when all
leaf partitions have been pruned, leaving the dummy root as the sole
entry. Assert this invariant (nrels == 1) and skip the ctid requirement.
Also adjust ExecModifyTable() to tolerate invalid ri_RowIdAttNo for
partitioned tables, which is safe since no rows will be processed in
this case.

Bug: #19099
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19099-e05dcfa022fe553d%40postgresql.org
Backpatch-through: 14
2026-01-23 10:23:26 +09:00
Tom Lane
9f7c803c91 Remove faulty Assert in partitioned INSERT...ON CONFLICT DO UPDATE.
Commit f16241bef mistakenly supposed that INSERT...ON CONFLICT DO
UPDATE rejects partitioned target tables.  (This may have been
accurate when the patch was written, but it was already obsolete
when committed.)  Hence, there's an assertion that we can't see
ItemPointerIndicatesMovedPartitions() in that path, but the assertion
is triggerable.

Some other places throw error if they see a moved-across-partitions
tuple, but there seems no need for that here, because if we just retry
then we get the same behavior as in the update-within-partition case,
as demonstrated by the new isolation test.  So fix by deleting the
faulty Assert.  (The fact that this is the fix doubtless explains
why we've heard no field complaints: the behavior of a non-assert
build is fine.)

The TM_Deleted case contains a cargo-culted copy of the same Assert,
which I also deleted to avoid confusion, although I believe that one
is actually not triggerable.

Per our code coverage report, neither the TM_Updated nor the
TM_Deleted case were reached at all by existing tests, so this
patch adds tests for both.

Reported-by: Dmitry Koval <d.koval@postgrespro.ru>
Author: Joseph Koshakow <koshy44@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/f5fffe4b-11b2-4557-a864-3587ff9b4c36@postgrespro.ru
Backpatch-through: 14
2026-01-22 18:35:31 -05:00
Thomas Munro
f1c6b153ca jit: Add missing inline pass for LLVM >= 17.
With LLVM >= 17, transform passes are provided as a string to
LLVMRunPasses. Only two strings were used: "default<O3>" and
"default<O0>,mem2reg".

With previous LLVM versions, an additional inline pass was added when
JIT inlining was enabled without optimization. With LLVM >= 17, the code
would go through llvm_inline, prepare the functions for inlining, but
the generated bitcode would be the same due to the missing inline pass.

This patch restores the previous behavior by adding an inline pass when
inlining is enabled but no optimization is done.

This fixes an oversight introduced by 76200e5e when support for LLVM 17
was added.

Backpatch-through: 14
Author: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Andreas Karlsson <andreas@proxel.se>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Pierre Ducroquet <p.psql@pinaraf.info>
Reviewed-by: Matheus Alcantara <matheusssilv97@gmail.com>
Discussion: https://postgr.es/m/CAO6_XqrNjJnbn15ctPv7o4yEAT9fWa-dK15RSyun6QNw9YDtKg%40mail.gmail.com
2026-01-22 16:10:58 +13:00
Michael Paquier
3304e97b1b pg_stat_statements: Fix crash in list squashing with Vars
When IN/ANY clauses contain both constants and variable expressions, the
optimizer transforms them into separate structures: constants become
an array expression while variables become individual OR conditions.

This transformation was creating an overlap with the token locations,
causing pg_stat_statements query normalization to crash because it
could not calculate the amount of bytes remaining to write for the
normalized query.

This commit disables squashing for mixed IN list expressions when
constructing a scalar array op, by setting list_start and list_end
to -1 when both variables and non-variables are present.  Some
regression tests are added to PGSS to verify these patterns.

Author: Sami Imseih <samimseih@gmail.com>
Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com>
Discussion: https://postgr.es/m/CAA5RZ0ts9qiONnHjjHxPxtePs22GBo4d3jZ_s2BQC59AN7XbAA@mail.gmail.com
Backpatch-through: 18
2026-01-20 08:11:16 +09:00
Robert Haas
c80b0c9d63 Don't set the truncation block length greater than RELSEG_SIZE.
When faced with a relation containing more than 1 physical segment
(i.e. >1GB, with normal settings), the previous code could compute a
truncation block length greater than RELSEG_SIZE, which could lead to
restore failures of this form:

file "%s" has truncation block length %u in excess of segment size %u

The fix is simply to clamp the maximum computed truncation_block_length
to RELSEG_SiZE. I have also added some comments to clarify the logic.

The test case was written by Oleg Tkachenko, but I have rewritten its
comments.

Reported-by: Oleg Tkachenko <oatkachenko@gmail.com>
Diagnosed-by: Oleg Tkachenko <oatkachenko@gmail.com>
Co-authored-by: Robert Haas <rhaas@postgresql.org>
Co-authored-by: Oleg Tkachenko <oatkachenko@gmail.com>
Reviewed-by: Amul Sul <sulamul@gmail.com>
Backpatch-through: 17
Discussion: http://postgr.es/m/00FEFC88-EA1D-4271-B38F-EB741733A84A@gmail.com
2026-01-19 12:09:48 -05:00
Richard Guo
7650eabb66 Fix unsafe pushdown of quals referencing grouping Vars
When checking a subquery's output expressions to see if it's safe to
push down an upper-level qual, check_output_expressions() previously
treated grouping Vars as opaque Vars.  This implicitly assumed they
were stable and scalar.

However, a grouping Var's underlying expression corresponds to the
grouping clause, which may be volatile or set-returning.  If an
upper-level qual references such an output column, pushing it down
into the subquery is unsafe.  This can cause strange results due to
multiple evaluation of a volatile function, or introduce SRFs into
the subquery's WHERE/HAVING quals.

This patch teaches check_output_expressions() to look through grouping
Vars to their underlying expressions.  This ensures that any
volatility or set-returning properties in the grouping clause are
detected, preventing the unsafe pushdown.

We do not need to recursively examine the Vars contained in these
underlying expressions.  Even if they reference outputs from
lower-level subqueries (at any depth), those references are guaranteed
not to expand to volatile or set-returning functions, because
subqueries containing such functions in their targetlists are never
pulled up.

Backpatch to v18, where this issue was introduced.

Reported-by: Eric Ridge <eebbrr@gmail.com>
Diagnosed-by: Tom Lane <tgl@sss.pgh.pa.us>
Author: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/7900964C-F99E-481E-BEE5-4338774CEB9F@gmail.com
Backpatch-through: 18
2026-01-19 11:14:51 +09:00
Tom Lane
6574bee645 Update time zone data files to tzdata release 2025c.
This is pretty pro-forma for our purposes, as the only change
is a historical correction for pre-1976 DST laws in
Baja California.  (Upstream made this release mostly to update
their leap-second data, which we don't use.)  But with minor
releases coming up, we should be up-to-date.

Backpatch-through: 14
2026-01-18 14:54:47 -05:00
Michael Paquier
69ee81932a Fix error message related to end TLI in backup manifest
The code adding the WAL information included in a backup manifest is
cross-checked with the contents of the timeline history file of the end
timeline.  A check based on the end timeline, when it fails, reported
the value of the start timeline in the error message.  This error is
fixed to show the correct timeline number in the report.

This error report would be confusing for users if seen, because it would
provide an incorrect information, so backpatch all the way down.

Oversight in 0d8c9c1210.

Author: Man Zeng <zengman@halodbtech.com>
Discussion: https://postgr.es/m/tencent_0F2949C4594556F672CF4658@qq.com
Backpatch-through: 14
2026-01-18 17:24:58 +09:00
Heikki Linnakangas
9b6714ed9a Fix crash in test function on removable_cutoff(NULL)
The function is part of the injection_points test module and only used
in tests. None of the current tests call it with a NULL argument, but
it is supposed to work.

Backpatch-through: 17
2026-01-16 14:43:32 +02:00
Amit Langote
f335457e8a Fix rowmark handling for non-relation RTEs during executor init
Commit cbc127917e introduced tracking of unpruned relids to skip
processing of pruned partitions. PlannedStmt.unprunableRelids is
computed as the difference between PlannerGlobal.allRelids and
prunableRelids, but allRelids only contains RTE_RELATION entries.
This means non-relation RTEs (VALUES, subqueries, CTEs, etc.) are
never included in unprunableRelids, and consequently not in
es_unpruned_relids at runtime.

As a result, rowmarks attached to non-relation RTEs were incorrectly
skipped during executor initialization. This affects any DML statement
that has rowmarks on such RTEs, including MERGE with a VALUES or
subquery source, and UPDATE/DELETE with joins against subqueries or
CTEs. When a concurrent update triggers an EPQ recheck, the missing
rowmark leads to incorrect results.

Fix by restricting the es_unpruned_relids membership check to
RTE_RELATION entries only, since partition pruning only applies to
actual relations. Rowmarks for other RTE kinds are now always
processed.

Bug: #19355
Reported-by: Bihua Wang <wangbihua.cn@gmail.com>
Diagnosed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Diagnosed-by: Tender Wang <tndrwang@gmail.com>
Author: Dean Rasheed <dean.a.rasheed@gmail.com>
Discussion: https://postgr.es/m/19355-57d7d52ea4980dc6@postgresql.org
Backpatch-through: 18
2026-01-16 14:53:32 +09:00
Amit Langote
1943ceb388 Fix segfault from releasing locks in detached DSM segments
If a FATAL error occurs while holding a lock in a DSM segment (such
as a dshash lock) and the process is not in a transaction, a
segmentation fault can occur during process exit.

The problem sequence is:

 1. Process acquires a lock in a DSM segment (e.g., via dshash)
 2. FATAL error occurs outside transaction context
 3. proc_exit() begins, calling before_shmem_exit callbacks
 4. dsm_backend_shutdown() detaches all DSM segments
 5. Later, on_shmem_exit callbacks run
 6. ProcKill() calls LWLockReleaseAll()
 7. Segfault: the lock being released is in unmapped memory

This only manifests outside transaction contexts because
AbortTransaction() calls LWLockReleaseAll() during transaction
abort, releasing locks before DSM cleanup. Background workers and
other non-transactional code paths are vulnerable.

Fix by calling LWLockReleaseAll() unconditionally at the start of
shmem_exit(), before any callbacks run. Releasing locks before
callbacks prevents the segfault - locks must be released before
dsm_backend_shutdown() detaches their memory. This is safe because
after an error, held locks are protecting potentially inconsistent
data anyway, and callbacks can acquire fresh locks if needed.

Also add a comment noting that LWLockReleaseAll() must be safe to
call before LWLock initialization (which it is, since
num_held_lwlocks will be 0), plus an Assert for the post-condition.

This fix aligns with the original design intent from commit
001a573a2, which noted that backends must clean up shared memory
state (including releasing lwlocks) before unmapping dynamic shared
memory segments.

Reported-by: Rahila Syed <rahilasyed90@gmail.com>
Author: Rahila Syed <rahilasyed90@gmail.com>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Discussion: https://postgr.es/m/CAH2L28uSvyiosL+kaic9249jRVoQiQF6JOnaCitKFq=xiFzX3g@mail.gmail.com
Backpatch-through: 14
2026-01-16 13:14:21 +09:00
Andres Freund
a80811e592 pgindent fix for 8077649907
Per buildfarm member koel.

Backpatch-through: 18
2026-01-15 14:56:59 -05:00
Heikki Linnakangas
9ed411e084 Fix 'unexpected data beyond EOF' on replica restart
On restart, a replica can fail with an error like 'unexpected data
beyond EOF in block 200 of relation T/D/R'. These are the steps to
reproduce it:

- A relation has a size of 400 blocks.
  - Blocks 201 to 400 are empty.
  - Block 200 has two rows.
  - Blocks 100 to 199 are empty.
- A restartpoint is done
- Vacuum truncates the relation to 200 blocks
- A FPW deletes a row in block 200
- A checkpoint is done
- A FPW deletes the last row in block 200
- Vacuum truncates the relation to 100 blocks
- The replica restarts

When the replica restarts:

- The relation on disk starts at 100 blocks, because all the
  truncations were applied before restart.
- The first truncate to 200 blocks is replayed. It silently fails, but
  it will still (incorrectly!) update the cache size to 200 blocks
- The first FPW on block 200 is applied. XLogReadBufferForRead relies
  on the cached size and incorrectly assumes that the page already
  exists in the file, and thus won't extend the relation.
- The online checkpoint record is replayed, calling smgrdestroyall
  which causes the cached size to be discarded
- The second FPW on block 200 is applied. This time, the detected size
  is 100 blocks, an extend is attempted. However, the block 200 is
  already present in the buffer cache due to the first FPW. This
  triggers the 'unexpected data beyond EOF'.

To fix, update the cached size in SmgrRelation with the current size
rather than the requested new size, when the requested new size is
greater.

Author: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Discussion: https://www.postgresql.org/message-id/CAO6_Xqrv-snNJNhbj1KjQmWiWHX3nYGDgAc=vxaZP3qc4g1Siw@mail.gmail.com
Backpatch-through: 14
2026-01-15 21:02:54 +02:00
Andres Freund
7f1b3a4cea aio: io_uring: Fix danger of completion getting reused before being read
We called io_uring_cqe_seen(..., cqe) before reading cqe->res. That allows the
completion to be reused, which in turn could lead to cqe->res being
overwritten. The window for that is very narrow and the likelihood of it
happening is very low, as we should never actually utilize all CQEs, but the
consequences would be bad.

This bug was reported to me privately.

Backpatch-through: 18
Discussion: https://postgr.es/m/bwo3e5lj2dgi2wzq4yvbyzu7nmwueczvvzioqsqo6azu6lm5oy@pbx75g2ach3p
2026-01-15 11:09:49 -05:00
Heikki Linnakangas
09532a78b8 Add check for invalid offset at multixid truncation
If a multixid with zero offset is left behind after a crash, and that
multixid later becomes the oldest multixid, truncation might try to
look up its offset and read the zero value. In the worst case, we
might incorrectly use the zero offset to truncate valid SLRU segments
that are still needed. I'm not sure if that can happen in practice, or
if there are some other lower-level safeguards or incidental reasons
that prevent the caller from passing an unwritten multixid as the
oldest multi. But better safe than sorry, so let's add an explicit
check for it.

In stable branches, we should perhaps do the same check for
'oldestOffset', i.e. the offset of the old oldest multixid (in master,
'oldestOffset' is gone). But if the old oldest multixid has an invalid
offset, the damage has been done already, and we would never advance
past that point. It's not clear what we should do in that case. The
check that this commit adds will prevent such an multixid with invalid
offset from becoming the oldest multixid in the first place, which
seems enough for now.

Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
Discussion: Discussion: https://www.postgresql.org/message-id/000301b2-5b81-4938-bdac-90f6eb660843@iki.fi
Backpatch-through: 14
2026-01-15 16:49:42 +02:00