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54027 commits

Author SHA1 Message Date
Fujii Masao
802dc79df6 Remove replication slot advice from MultiXact wraparound hints
Previously, MultiXactId wraparound hints suggested dropping stale
replication slots. While that advice is appropriate for transaction ID
wraparound, where replication slots can hold back XID horizons,
it was misleading for MultiXactId wraparound. Following it could lead
users to drop replication slots unnecessarily without helping resolve
the MultiXactId wraparound condition.

MultiXact cleanup is not directly delayed by replication slots.
Instead, it depends on whether old MultiXactIds can still be seen
as live by running transactions.

This commit removes the replication slot advice from MultiXactId
wraparound hints, and documents that stale replication slots are
normally not relevant to resolving MultiXactId wraparound problems.

Backpatch to all supported branches.

BUG #18876
Reported-by: Haruka Takatsuka <harukat@sraoss.co.jp>
Author: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/18876-0d0b53bad5a1f4c1@postgresql.org
Backpatch-through: 14
2026-07-03 11:22:55 +09:00
Tom Lane
255bce4488 btree_gist: fix NaN handling in float4/float8 opclasses.
The float4 and float8 btree_gist opclasses compared keys with raw C
operators (==, <, >).  IEEE 754 makes every comparison involving NaN
false, so GiST disagreed with the regular float comparison operators
and with the btree opclass, which uses float[4|8]_cmp_internal()
(so that all NaNs are equal and NaN sorts after every non-NaN value).

In addition, the penalty and distance functions were not careful
about NaNs, and the penalty functions could also misbehave for IEEE
infinities.  Wrong answers from the penalty functions would probably
do no more than make the index non-optimal, but the distance mistakes
were visible from SQL.

To fix, make the comparison functions rely on the same NaN-aware
comparison functions the core code uses, and rewrite the penalty
and distance functions to follow the rules that NaNs are equal
but maximally far away from non-NaNs.  The penalty_num() code was
formerly shared between integral and float cases, but I chose to make
two copies so that the integral cases are not saddled with the extra
logic for NaNs and infinities/overflows.  I also rewrote it as static
inline functions instead of an unreadable and uncommented macro.

The float penalty functions were previously unreached by the
regression tests, so add new test cases to exercise them.

There's no on-disk format change, but users who have NaN entries
in a btree_gist index would be well advised to reindex it.

Bug: #19501
Bug: #19524
Reported-by: Man Zeng <zengman@halodbtech.com>
Reported-by: Yuelin Wang <3020001251@tju.edu.cn>
Author: Bill Kim <billkimjh@gmail.com>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19501-3bff3bbc97f1e7c9@postgresql.org
Discussion: https://postgr.es/m/19524-9559d302c8455664@postgresql.org
Discussion: https://postgr.es/m/CAMQXxcgbtD2LXfX0tpgvOizxP-XxrCHV2ZDy4By_TZnJMsxXWQ@mail.gmail.com
Backpatch-through: 14
2026-07-01 13:27:22 -04:00
Richard Guo
309dc4526d Use plpythonu in plpython tests added by commit 0b7719f74
Commit 0b7719f74 added regression tests that spell the language name
as plpython3u.  That works on the master branch, but on v14 the
plpython tests must use the unversioned name plpythonu: the plpython3u
extension is built only in Python 3 builds, and for those builds
regress-python3-mangle.mk rewrites plpythonu to plpython3u in the test
files.  In a Python 2 build the new tests instead failed with
"language \"plpython3u\" does not exist".

Spell the language as plpythonu in the new tests, matching every other
plpython test in this branch, so they work in both Python 2 and Python
3 builds.  This is needed only in v14; later branches no longer
support Python 2 and have dropped the mangling step.

Per buildfarm member hippopotamus.
2026-06-29 14:21:15 +09:00
Richard Guo
0b7719f744 plpython: Fix NULL pointer dereferences for broken sequence and mapping objects
PL/Python and its hstore and jsonb transforms build SQL values from
Python containers by calling Python C API functions that can return
NULL, and in several places the result was used without first checking
it.

On the sequence side, PySequence_GetItem() is used when converting a
returned sequence into a SQL array or composite value, when reading
the argument list passed to plpy.execute() or plpy.cursor(), and when
reading the list of type names given to plpy.prepare().  On the
mapping side, the hstore and jsonb transforms call PyMapping_Size()
and PyMapping_Items() and then index the result with PyList_GetItem()
and PyTuple_GetItem().

All of these return NULL (or -1), with a Python exception set, for a
broken object: for example one whose __getitem__() or items() raises,
or which reports a length that disagrees with what it actually yields.
The unchecked result was then dereferenced, crashing the backend.

Fix this by checking the result of each call and reporting a regular
error if it failed, so that the underlying Python exception is
surfaced instead of taking down the session.

Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Discussion: https://postgr.es/m/CAMbWs49BKM9wP6m8bCXEpHwQKp7usvOGV6Jf=J7FYr_BCpxLqg@mail.gmail.com
Backpatch-through: 14
2026-06-29 11:44:35 +09:00
Richard Guo
e520ad34b4 plperl: Fix NULL pointer dereference for forged array object
In get_perl_array_ref(), for a PostgreSQL::InServer::ARRAY object, we
look up its "array" key with hv_fetch_string() and then inspect the
returned SV.  However, hv_fetch_string() returns a NULL pointer when
the key is absent, and the code dereferenced that result without first
checking whether the pointer itself was NULL.  As a result, a plperl
function returning a forged PostgreSQL::InServer::ARRAY object that
lacks the "array" key would crash the backend with a segmentation
fault.

Fix this by checking the pointer returned by hv_fetch_string() before
dereferencing it, matching how other callers in this file already
guard the result.  With the check in place, such an object falls
through to the existing error report instead of crashing.

Author: Xing Guo <higuoxing@gmail.com>
Reviewed-by: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CACpMh+DYgcnqZwQLXXuxQcehJTd7T8UmKWSLsK4mFBEp9G2ajA@mail.gmail.com
Backpatch-through: 14
2026-06-24 09:17:36 +09:00
Michael Paquier
e8fbe5d838 doc: Describe better handling of indexes in ALTER TABLE ATTACH PARTITION
When ALTER TABLE ... ATTACH PARTITION matches partition indexes to the
parent table's indexes, invalid indexes are skipped.  This commit
improves the documentation to describe what e90e9275f5 has changed:
invalid indexes are skipped, and only valid indexes are considered for a
match.

Author: Mohamed Ali <moali.pg@gmail.com>
Reviewed-by: Sami Imseih <samimseih@gmail.com>
Discussion: https://postgr.es/m/CAGnOmWpAMaE-BOkpwM6mJnHcpS2QZ8yLSSaqmz+vryEsbCWWWA@mail.gmail.com
Backpatch-through: 14
2026-06-23 16:52:21 +09:00
Tom Lane
4b3bc6b714 Make pg_mkdir_p() tolerant of a concurrent directory creation.
pg_mkdir_p creates each missing path component with a stat() followed
by mkdir().  If the stat() reports the component as absent but another
process creates it in the window before this process's mkdir(), mkdir()
fails with EEXIST and pg_mkdir_p treated that as a hard error -- unlike
"mkdir -p", which is meant to be idempotent and race-tolerant.

This shows up when several processes concurrently create paths that
share an ancestor directory: for example, parallel initdb runs whose
data directories live under a common temporary directory.  One process
wins the race to create the shared ancestor and the others fail with
    could not create directory "...": File exists

Fix this race condition by first trying mkdir() and only attempting
stat() if it fails with EEXIST.

On Windows, there's an additional problem: stat() opens a file handle
and participates in share-mode locking, which means it can transiently
fail on a directory another process is concurrently creating.  Use
GetFileAttributes() instead: it requests only FILE_READ_ATTRIBUTES
and is exempt from share-mode denial, so it reliably sees a
concurrently-created directory.

I (tgl) also chose to back-patch 039f7ee0f's effects on this function,
so that pgmkdirp.c remains identical in all live branches.

Author: Andrew Dunstan <andrew@dunslane.net>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/3ca004de-e49b-4471-b8aa-fd656e70f68c@dunslane.net
Backpatch-through: 14
2026-06-19 12:52:00 -04:00
Nathan Bossart
b2a6a27bac Silence "may be used uninitialized" compiler warning.
Newer gcc warns that this "actual_arg_types" variable may be used
uninitialized, but visual inspection indicates there's no bug.  To
silence the warning, initialize the variable to zeros.

Bug: #19485
Reported-by: Hans Buschmann <buschmann@nidsa.net>
Tested-by: Erik Rijkers <er@xs4all.nl>
Tested-by: Hans Buschmann <buschmann@nidsa.net>
Reviewed-by: Tristan Partin <tristan@partin.io>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Discussion: https://postgr.es/m/19485-2b03231a775756f1%40postgresql.org
Discussion: https://postgr.es/m/6c52a1a6612948519468d46cb224a8c4%40nidsa.net
2026-06-18 11:29:49 -05:00
Tom Lane
1f6b2295f9 hstore_plperl: Add CHECK_FOR_INTERRUPTS() in reference-unwinding loop.
Add CHECK_FOR_INTERRUPTS() to the while loop in plperl_to_hstore()
that dereferences chains of Perl references, so that a circular
reference (e.g. $x = \$x) can be cancelled by the user instead of
spinning indefinitely.  (We looked at detecting such circular
references, but it seems more trouble than it's worth.)

This is a follow-up to da82fbb8f, which fixed the same issue in
SV_to_JsonbValue() in jsonb_plperl.

Author: Aleksander Alekseev <aleksander@tigerdata.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAJ7c6TPbjkzUk4qJ5dHvDNEz0hBuFue3A-XWz_=897z+BC+z8A@mail.gmail.com
Backpatch-through: 14
2026-06-18 12:22:55 -04:00
Nathan Bossart
1d216f1e77 doc: Fix "Prev" link, take 2.
Commit 6678b58d78 fixed a wrong "Prev" link by changing the link
generation code to use [position()=last()] instead of [last()] in
the predicate on the union of reverse axes.  Unfortunately, that
caused documentation builds to take much longer.  To fix, combine
the "preceding" and "ancestor" steps into one "preceding" step and
one "ancestor" step, and revert the predicate back to [last()].
The smaller union evades the libxml2 bug while avoiding the build
time regression.

Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Tested-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/1132496.1781718007%40sss.pgh.pa.us
Backpatch-through: 14
2026-06-18 09:31:27 -05:00
Amit Langote
3640143270 Report undefined jsonpath variable when no variables are supplied
The two-argument jsonb @? and @@ operators invoke the jsonpath executor
with no variable set.  In that case getJsonPathVariable() treated any
"$name" reference as JSON null and continued evaluating, instead of
reporting the variable as undefined.

This produced incorrect results -- for example '42'::jsonb @? '$"x"'
returned true -- and, for some malformed or hostile jsonpath expressions
with deeply nested predicates, allowed essentially unbounded memory
consumption that could get the backend killed by the OOM killer.

Report the undefined variable as an error in this case as well, reusing
the message already emitted when a variable is not found among supplied
variables.  This matches the behavior of v17 and later, where the
jsonpath executor was reorganized.  Stopping at the first undefined
variable reference also resolves the reported memory-growth case.

Note this is a user-visible change in the back branches: a jsonpath
expression that references a variable while no variables are supplied now
raises an error rather than silently evaluating it as NULL.  The previous
behavior was incorrect, so the change is judged worthwhile.

Bug: #19458
Reported-by: Andrey Rachitskiy <pl0h0yp1@gmail.com>
Author: Andrey Rachitskiy <pl0h0yp1@gmail.com>
Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
Reviewed-by: Nikita Malakhov <hukutoc@gmail.com>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/19458-a69c98bc498333ba@postgresql.org
Backpatch-through: 14-16
2026-06-18 15:51:38 +09:00
Tom Lane
639fff5118 jsonb_plperl, jsonb_plpython: Fix unguarded recursion and loops.
Add check_stack_depth() to Jsonb_to_SV, SV_to_JsonbValue,
PLyObject_FromJsonbContainer, and PLyObject_ToJsonbValue.  Without
this, deeply nested JSONB values can crash the backend with SIGSEGV
instead of raising a proper error.

Also add CHECK_FOR_INTERRUPTS() to the while loop in SV_to_JsonbValue
that dereferences chains of Perl references, so that a circular
reference (e.g. $x = \$x) can be cancelled by the user instead of
spinning indefinitely.  (We looked at detecting such circular
references, but it seems more trouble than it's worth.)

Author: Aleksander Alekseev <aleksander@tigerdata.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAJ7c6TPbjkzUk4qJ5dHvDNEz0hBuFue3A-XWz_=897z+BC+z8A@mail.gmail.com
Backpatch-through: 14
2026-06-17 11:04:41 -04:00
Michael Paquier
d75146456f Fix another instability in recovery TAP test 004_timeline_switch
The test did not wait for the standby to be connected to the primary.
This breaks one assumption at the beginning of the test, where the
primary is stopped to ensure that all its records are flushed to both
standbys before moving on with its next steps.

If standby_1 finishes ahead of standby_2, the test would be able work
fine as the former waits for the latter.  The opposite is not true,
standby_2 getting ahead of standby_1 would cause the test to fail on
timeout when standby_1 attempts to connect to standby_2.

This commit adds an additional polling query after the two standbys are
started, checking that both standbys are connected to the primary before
processing with the initial steps of the test.

Like 7185eddf05, backpatch down to v14.

Author: Sergey Tatarintsev <s.tatarintsev@postgrespro.ru>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/fea4190e-f8b5-4432-a52d-bcbee5f34366@postgrespro.ru
Backpatch-through: 14
2026-06-17 08:42:13 +09:00
Álvaro Herrera
0939aad564
logical decoding: Correctly free speculative insertion
The error path in ReorderBufferProcessTXN was not freeing
(reorderbuffer.c's representation of) a speculative insertion record
correctly.  In assert-enabled builds, this leads to an assertion
failure.  In production builds, I see no effect; there may be a small
transient leak, but in an improbable code path such as this, such a leak
is not of any significance.  For users running with assertions enabled,
the crash is annoying.

Fix by having ReorderBufferProcessTXN() free the speculative insert
ahead of freeing the rest of the transaction, and no longer try to
handle that insert as a separate argument to ReorderBufferResetTXN().

This code came in with commit 7259736a6e (14-era).  Backpatch all the
way back.

In branches 14-16, also backpatch the assertion that originally fails in
the problem scenario, which was added by dbed2e3662 (originally
backpatched to 17), that at the end of ReorderBufferReturnTXN() the
in-memory size of the transaction is zero.

Author: Vishal Prasanna <vishal.g@zohocorp.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Backpatch-through: 14
Discussion: https://postgr.es/m/19c7623e882.4080fd5426212.311756747309556767@zohocorp.com
2026-06-16 18:13:15 +02:00
Heikki Linnakangas
f528a5606a Fix int32 overflow in ltree_compare()
The expression (len_diff * 10 * (an + 1)) used as the return value of
ltree_compare() is computed at int32 width.  With LTREE_MAX_LEVELS =
65535, the product can exceed INT32_MAX once an ltree has more than
~14,653 levels, which causes the result to wrap and invert its sign.
That corrupts btree ordering as well as the "magnitude" consumed by
ltree_penalty() for GiST page splits.

To fix, split ltree_compare() into two functions.  The new
ltree_compare_distance() function returns a float, which won't
overflow.  It's used by the ltree_penalty() caller.  All the other
callers only care about the sign of the return value, i.e. which of
the arguments is greater, so change ltree_compare() to not multiply
the result with (10 * (an + 1)), which avoids the overflow for those
callers.

Existing btree or GiST indexes on ltree columns containing values with
more than ~14,653 levels may be corrupt and should be REINDEXed.

Add a regression test based on the reporter's PoC.

Author: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Reported-by: 王跃林 <violin0613@tju.edu.cn>
Discussion: https://www.postgresql.org/message-id/AI6AnABgKW93Qbx1jVzi84r9.8.1781322625756.Hmail.3020001251%40tju.edu.cn
Backpatch-through: 14
2026-06-16 09:31:23 +03:00
Tom Lane
2a00840e8c Clean up quoting of variable strings within replication commands.
Our handling of quoting within replication commands was pretty
sloppy, typically looking like
        appendStringInfo(&cmd, " SLOT \"%s\"", options->slotname);
This is fine as long as options->slotname doesn't contain a double
quote mark, but what if it does?  In principle this'd allow injection
of harmful options into replication commands, in the probably-unlikely
case that a slot name comes from untrustworthy input.  We ought to
clean that up.

Moreover, even the places that were trying to be more careful
generally got it wrong, because they used quoting subroutines
intended for SQL commands rather than something that will work
with the replication-command scanner repl_scanner.l.  For example,
several places naively use PQescapeLiteral() to quote option values
for replication commands.  If the string contains a backslash,
PQescapeLiteral() will produce E'...' literal syntax, which
repl_scanner.l doesn't recognize.  Another near miss was to use
quote_identifier() to quote identifiers.  That function won't quote
valid lowercase identifiers unless they match SQL keywords ... but in
this context, replication keywords are what matter.  Neither of these
errors seem to risk string injection, but they definitely can cause
syntax errors in replication commands that ought to be valid.

We can clean all this up by using simple quoting logic that just
doubles single or double quotes respectively.

Or at least, we could if repl_scanner.l handled doubled double quotes
in identifiers, but for some reason it doesn't!  So the first step in
this fix has to be to fix that.  (The fact that we'll later reject
slot names containing double quotes is very far short of justifying
this omission.)

Having done that, this patch runs around and applies correct
quoting in all places that generate replication commands containing
strings coming from outside the immediate context.  Probably some
of these places are safe because of restrictions elsewhere, but it
seems best to just quote all the time.

This was originally reported as a security bug, which it could be
if replication slot names or parameters were to originate from
untrustworthy sources.  But the security team concluded that that
was a very improbable situation, so we're just going to fix this
as a regular bug.

Reported-by: Team Dhiutsa
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Discussion: https://postgr.es/m/1648659.1781287310@sss.pgh.pa.us
Backpatch-through: 14
2026-06-15 15:35:37 -04:00
Nathan Bossart
924172c565 doc: Fix "Prev" link.
Presently, the "Prev" link on the page for background workers sends
you to the middle of the previous chapter instead of the actual
previous page.  This appears to be caused by a libxml2 bug, but
regardless, a minimal fix is to change the link generation code to
use [position()=last()] instead of [last()] in the predicate on the
union of reverse axes.

Reviewed-by: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Discussion: https://postgr.es/m/aim4AZorFKaC7Wrf%40nathan
Backpatch-through: 14
2026-06-15 12:16:38 -05:00
Heikki Linnakangas
1b79c8d1a5 Fix PQdescribePrepared with more than 7498 params
If a query has more than 7498 params, the ParameterDescription message
exceeds the 30000 byte limit on messages that are not specifically
marked as possibly being longer than that (VALID_LONG_MESSAGE_TYPE).
To fix, add ParameterDescription to the list.

Author: Ning Sun <classicning@gmail.com>
Discussion: https://www.postgresql.org/message-id/dbfb4b65-0aa8-470a-8b87-b6496160b28a@gmail.com
Backpatch-through: 14
2026-06-15 11:38:40 +03:00
Michael Paquier
102689827f Trim regression test expected output for xml
This commit reduces the number of expected output files for the "xml"
test from three to two (well, mostly one, see below for details).

xml_2.out existed to handle some differences in output due to libxml2
2.9.3, due to some error context missing (085423e3e3).  This file is
removed, by tweaking the XML inputs to trigger the same error patterns
for the problematic 2.9.3 and other libxml2 versions.  This part is
authored by Tom Lane.

xml_1.out (no libxml2 support) is reduced in size by adding an \if query
that exits the test early.  This still checks NO_XML_SUPPORT() through
xmlin().  The rest of the test is skipped if XML input cannot be
handled by the backend.  This part has been written by me.

Author: Tom Lane <tgl@sss.pgh.pa.us>
Author: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/aiu6CXO67q-s70n5@paquier.xyz
Backpatch-through: 14
2026-06-15 11:38:02 +09:00
Tom Lane
b94996ddd7 Doc: remove stale entry for removed aclitem[] ~ aclitem operator.
Commit 2f70fdb06 removed the deprecated containment operator
~(aclitem[],aclitem) from the catalogs, but missed removing its entry
from the documentation.  (Arguably the blame should fall on c62dd80cd,
which added this entry in contravention of the longstanding policy
that we don't document deprecated aliases in the first place.)

Author: Shinya Kato <shinya11.kato@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAOzEurQSyR5psWukyhUz1LtxyO55C2Vfp0Fmt8w2jGKxhszQmQ@mail.gmail.com
Backpatch-through: 14
2026-06-14 11:01:48 -04:00
Alexander Korotkov
af09b18cba amcheck: Use correct varlena size accessor in bt_normalize_tuple()
bt_normalize_tuple() uses VARSIZE() to get the size of varlena, even though
it's not yet known, that it has a 4-byte header.  Fix this by replacing a
accessor with a universal VARSIZE_ANY().

Backpatch to all supported versions.

Reported-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/7ckc7oka4bvafkf5bwlqs6ygrhlsbhz25ppozfch7zbuxcx3rf%40e4pr4oqenalc
Author: Andrey Borodin <x4mmm@yandex-team.ru>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Backpatch-through: 14
2026-06-14 04:06:43 +03:00
Andrew Dunstan
7974f94a02 Adjust cross-version upgrade tests for seg_out() fix
Commit 0e1f1ed157 taught seg_out() to print the certainty indicator
on an interval's upper boundary, but it was back-patched only as far
as v14.  When upgrading from an older release, the old server prints
the one test_seg row exercising that case ('4.6 .. ~7.0') without the
indicator, so the pre- and post-upgrade dumps do not match.  Make
AdjustUpgrade.pm delete just that row; seg's comparison function does
distinguish the certainty indicators, so the otherwise identical row
'4.6 .. 7.0' is unaffected.

Back-patch to all supported branches.

Per buildfarm members crake and fairywren.

Discussion: https://postgr.es/m/5ccbdbde-6467-4a10-bf4d-0be73a05ce8d@dunslane.net
2026-06-12 18:07:00 -04:00
Andrew Dunstan
b31fa1f87f Don't try to import a non-exported object in vcregress.pl
Commit ca9e9b08e4 wrongly tried to import devnull from File::Spec, but
it's not exported, you just call the method via the class. This was
harmless until modern perls complained, so stop doing that.

Per buildfarm failures.

Backpatch 14 thru 16
2026-06-12 10:20:34 -04:00
Daniel Gustafsson
086652c02f Fix compilation with OpenSSL 4
OpenSSL 4.0.0 changed some parameters and returnvalues to const, so
we need to update our declarations and subsequently cast away const-
ness from a few callsites to make libpq build without warnings. This
is tested with OpenSSL 1.1.1 through 4.0.0 as well as with LibreSSL.
No functional change is introduced, this commit only allows postgres
to be compiled against OpenSSL 4.0.0 without warnings.

There is also an errormessage change in OpenSSL 4.0.0 which needed
to be covered by our testharness.

This will be backpatched to all supported branches since they are
all equally likely to be built against OpenSSL 4.0.0 as it becomes
available in distributions.  Backpatching will be done once it has
been in master for a few days without issues.

Author: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/066B07BB-85FA-487C-BE8C-40F791CFC3C4@yesql.se
Backpatch-through: 14
2026-06-12 13:57:22 +02:00
Michael Paquier
a17f39aa2f Update expected regression test output for xml_2.out
This one has been forgotten in 8bf257aeba.  Per report from buildfarm
member massasauga.

Backpatch-through: 14
2026-06-12 12:39:40 +09:00
Fujii Masao
e3a4e9edd5 doc: fix reference for finding replication slots to drop
Commit a70bce43fb added instructions on how to recover if PostgreSQL
refuses to issue new transaction IDs because of imminent wraparound,
but when describing how to find replication slots that should be dropped,
it referred to pg_stat_replication where it should have referenced
pg_replication_slots.

In passing, decorate references to views with <structname> tags.

Backpatch to all supported versions.

Reported-By: Sanjaya Waruna <sanjaya.waruna@gmail.com>
Author: Laurenz Albe <laurenz.albe@cybertec.at>
Reviewed-by: Robert Treat <rob@xzilla.net>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/176767268098.1084085.10345048667224193115@wrigleys.postgresql.org
Backpatch-through: 14
2026-06-12 11:10:26 +09:00
Michael Paquier
41876c8d77 Fix handling of namespace nodes in xpath() (xml)
xpath() attempted to call xmlCopyNode() and xmlNodeDump() on a
XML_NAMESPACE_DECL, finishing with a confusing error:
=# SELECT xpath('//namespace::foo', '<root xmlns:foo="http://127.0.0.1"/>');
ERROR:  53200: could not copy node
CONTEXT:  SQL function "xpath" statement 1

xpath() is changed so as it goes through xmlXPathCastNodeToString()
instead, that is able to handle namespace nodes.  xml2 uses the same
solution.  This issue has been discovered while digging into
9d33a5a804.

Author: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/aioT7ui_ZJ9RMlfM@paquier.xyz
Backpatch-through: 14
2026-06-12 10:25:59 +09:00
Heikki Linnakangas
58b91fc73a seg: Fix seg_out() to preserve the upper boundary's certainty indicator
When printing the upper boundary of a seg interval, seg_out() decided
whether to emit the certainty indicator ('<', '>' or '~') by testing the
upper indicator (u_ext) for '<' and '>', but mistakenly tested the lower
indicator (l_ext) for '~'.  This is a copy-and-paste slip from the
symmetric code that prints the lower boundary a few lines above.

The consequences for valid input were:

  * A '~' on the upper boundary was dropped on output, e.g.
    '1.5 .. ~2.5'::seg printed as '1.5 .. 2.5'.

  * When the lower boundary carried '~' but the upper boundary had no
    indicator, the wrong test matched and sprintf(p, "%c", seg->u_ext)
    wrote a NUL byte (u_ext == '\0'), which truncated the result string
    and silently lost the entire upper boundary, e.g.
    '~6.5 .. 8.5'::seg printed as '~6.5 .. '.

Certainty indicators are documented to be preserved on output (they are
ignored by the operators, but kept as comments), so this broke the
input/output round-trip for the affected values.

The bug has existed since seg was added.  It went unnoticed because the
existing regression tests only exercised certainty indicators on
single-point segs, which are printed by a different branch of seg_out().
Add tests that place indicators on both boundaries of an interval.

Author: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://www.postgresql.org/message-id/CAON2xHPYeRRCEVAv8XfE18KsEsEHCiYcJ5fOsoxFuMEfpxF1=g@mail.gmail.com
Backpatch-through: 14
2026-06-11 12:34:45 +03:00
Michael Paquier
f3f901a53a xml2: Fix crash with namespace nodes in xpath_nodeset()
pgxmlNodeSetToText() passed nodeTab[i]->doc to xmlNodeDump() without
checking the node type, which could cause a crash as a
XML_NAMESPACE_DECL maps to a xmlNs struct.  The passed-in code would
then be dereferenced in xmlNodeDump().

This commit switches the code to render XML_NAMESPACE_DECL nodes with
xmlXPathCastNodeToString(), like xpath_table().  Some tests are added,
written by me.

Author: Andrey Chernyy <andrey.cherny@tantorlabs.com>
Co-authored-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/20260611031436.5afde3cb@andrnote
Backpatch-through: 14
2026-06-11 14:29:29 +09:00
Jeff Davis
1e04581729 dict_synonym.c: remove incorrect outlen.
Previously, outlen was miscalculated if case_sensitive was false and
str_tolower() changed the byte length of the string. If outlen was too
large, pnstrdup() would stop at the NUL terminator, preventing
overrun. But if outlen was too small, it would cause truncation.

Fix by just removing outlen. It was only used in a single site, which
could just as well use pstrdup().

Discussion: https://postgre.es/m/1101e1a3afbbabb503317069c40374b82e6f4cac.camel@j-davis.com
Reviewed-by: Tristan Partin <tristan@partin.io>
Backpatch-through: 14
2026-06-08 11:49:27 -07:00
Tom Lane
64778fac72 Fix missed checks for hashability of container-type equality.
The operators for array_eq, record_eq, range_eq, and multirange_eq
are all marked oprcanhash, but there's a pitfall: their hash functions
can fail at runtime if the contained type(s) are not hashable.
Therefore, the planner has to check hashability of the contained types
before deciding it can use hashing in these cases.  Not every place
had gotten this memo, and noplace at all had considered the issue
for ranges or multiranges.  In particular we could attempt to use
hashing for a ScalarArrayOpExpr on a container type when it won't
actually work, leading to "could not identify a hash function ..."
runtime failures.

For the most part we should fix this in the lookup functions provided
by lsyscache.c, to wit get_op_hash_functions and op_hashjoinable.
But there's a problem: get_op_hash_functions is not passed the input
data type it would need to check.  We mustn't change the API of that
exported function in a back-patched fix, and even if we wanted to,
its call sites in the executor mostly don't have easy access to the
required data type OID.  Fortunately, the executor call sites don't
actually need fixing, because it's expected that the planner verified
hashability before building a plan that requires it.  Therefore,
leave get_op_hash_functions as-is and invent a wrapper function
get_op_hash_functions_ext that does the additional checking needed
in the planner's uses.

We also need to fix hash_ok_operator (extending the fix in 647889667).

While at it, neaten up a couple of places in lookup_type_cache where
relevant code for multirange cases was written differently from the
code for other container types.

Note: while this touches pg_operator.dat, it's only to add oid_symbol
macros.  So there's no on-disk data change and no need for a
catversion bump.

Reported-by: Andrei Lepikhov <lepihov@gmail.com>
Author: Andrei Lepikhov <lepihov@gmail.com>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/ed221f95-f09b-4a9c-b05b-e1fed621ec87@gmail.com
Backpatch-through: 14
2026-06-08 11:48:18 -04:00
Nathan Bossart
673161b63e doc: Expand on proper use of refint.
The security team has received a couple of reports about potential
SQL injection via refint's trigger arguments.  We discussed this
while preparing CVE-2026-6637 and concluded that forcibly quoting
these arguments is more likely to break working code than to
prevent exploits.  Unlike data values, the table/column names come
from trigger arguments, and there is little reason for a trigger
author to put hostile inputs into those arguments.  So, let's
document it accordingly.

Reported-by: Nikolay Samokhvalov <nik@postgres.ai>
Reported-by: Alex Young <alex000young@gmail.com>
Reported-by: Satyanarayana Narlapuram <satyanarlapuram@gmail.com>
Suggested-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Reviewed-by: Christoph Berg <myon@debian.org>
Reviewed-by: Satyanarayana Narlapuram <satyanarlapuram@gmail.com>
Discussion: https://postgr.es/m/ahXP7z7nsfGPOZ3T%40nathan
Backpatch-through: 14
2026-06-08 10:33:52 -05:00
Fujii Masao
9e8fd9f7ab ecpg: Reject multiple header items in GET/SET DESCRIPTOR
Previously, ecpg accepted multiple descriptor header items in GET DESCRIPTOR
and SET DESCRIPTOR, but generated broken C code when they were used.
Although the grammar allowed this syntax, the implementation did not actually
support it.

This commit tightens the ecpg grammar so the header form of GET/SET DESCRIPTOR
accepts only a single header item, matching the implementation and preventing
generation of broken C code.

Also update the documentation synopsis accordingly.

Backpatch to all supported versions.

Author: Masashi Kamura <kamura.masashi@fujitsu.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Lakshmi G <lakshmigcdac@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/OS9PR01MB13174AD7D1829D0644B6BB90E9447A@OS9PR01MB13174.jpnprd01.prod.outlook.com
Backpatch-through: 14
2026-06-08 17:14:20 +09:00
Michael Paquier
a4ca91ea18 psql: Fix expanded aligned output
When a table's columns are narrower than the record header line, the
expanded aligned format produced misaligned output because the data
column width was not adjusted to match the record header width, leading
to output like:
+-[ RECORD 1 ]-+
| a | 10 |
| b | 20 |
+---+----+

This commit adjusts the output so as the column width match with the
header line, giving:
+-[ RECORD 1 ]-+
| a | 10       |
| b | 20       |
+---+----------+

Author: Pavel Stehule <pavel.stehule@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CAFj8pRCzGpsr9zTHbtTd4mGh2YPJqOEgLgt8JLiopuYA9_1xGw@mail.gmail.com
Backpatch-through: 14
2026-06-08 14:38:01 +09:00
Michael Paquier
1eda3eb075 pg_surgery: Fix off-by-one bug with heap offset
heap_force_common() declared a boolean array indexed with an
OffsetNumber for a size of MaxHeapTuplesPerPage.  OffsetNumbers are
1-based, so an input TID whose offset number equals MaxHeapTuplesPerPage
wrote one byte past the end of the stack array, crashing the server.

Like heapam_handler.c, this commit changes the array so as it uses a
0-based index, substracting one from the OffsetNumbers.

Reported-by: Wang Yuelin <violin0613@tju.edu.cn>
Reviewed-by: Ashutosh Sharma <ashu.coek88@gmail.com>
Discussion: https://postgr.es/m/20260604002256.40f1fd544@smtp.qiye.163.com
Backpatch-through: 14
2026-06-06 08:16:46 +09:00
Nathan Bossart
5b72d0279b refint: Remove plan cache.
Presently, refint stores plans in a per-backend cache to avoid
re-preparing in each call.  This has a few problems.  For one,
check_foreign_key() embeds the new key values in its cascade-UPDATE
queries, so a cached plan reuses the values from preparation.
Also, the cache is never invalidated, so it can return stale
entries that cause other problems.  There may very well be more
bugs lurking.

We could spend a lot of time trying to address all these problems,
but this module is primarily intended as sample code, and by all
indications, it sees minimal use.  Furthermore, there is a growing
consensus for removing refint in v20.  However, since we'll need to
support it on the back-branches for a while longer, it probably
still makes sense to fix some of the more egregious bugs.

Therefore, let's just remove refint's plan cache entirely.  That
means we'll re-prepare on every call, but that seems quite unlikely
to bother anyone.  On v17 and older versions, the regression test
for triggers fails after this change, so I've borrowed pieces of
commit 8cfbdf8f4d to fix it.

Author: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Discussion: https://postgr.es/m/CAJTYsWXU%2BfhuzrEd_bnrxyGH3%2Bny8QRQC2QHf3ws6s9iki3c2Q%40mail.gmail.com
Backpatch-through: 14
2026-06-05 12:08:05 -05:00
Michael Paquier
8bb935d619 Fix off-by-one with NFC recomposition for Hangul U+11A7 (TBASE)
The NFC recomposition incorrectly included TBASE as a valid T syllable,
which is incorrect based on the Unicode specification (TBASE is one
below the start of the range, range beginning at U+11A8).

This would cause the TBASE to be silently swallowed in the
normalization, leading to an incorrect result.

A couple of regression tests are added to check more patterns with
Hangul recomposition and decomposition, on top of a test to check the
problem with TBASE.  Diego has submitted the code fix, and I have
written the tests.

Author: Diego Frias <mail@dzfrias.dev>
Co-authored-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/B92ED640-7D4A-4505-B09F-3548F58CBB16@dzfrias.dev
Backpatch-through: 14
2026-06-05 07:50:18 +09:00
Tom Lane
262cc4df28 Improve reporting of invalid weight symbols in setweight() et al.
This commit addresses two related issues:

tsvector_filter() assumed it could print an incorrect weight value
with %c.  This could result in an invalidly-encoded error message
if the database encoding is multibyte and the char value has its
high bit set.  Weight values that are ASCII control characters
could render illegibly too.  Fix by printing such values in octal
(\ooo), similarly to how charout() would render them.

tsvector_setweight() and tsvector_setweight_by_filter() reported
the same unrecognized-weight error condition with elog(), as though
it were an internal error.  That'd not translate, would produce an
unwanted XX000 SQLSTATE code, and also reported the bad value as a
decimal integer which seems unhelpful.  Fix by refactoring so that
all three functions share one copy of the code that interprets a
weight argument.

The invalid-encoding aspect seems to me (tgl) to justify
back-patching.

Author: Ewan Young <kdbase.hack@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAON2xHNaeLAUzRCXL5AmXLcXaSE_gWAVjWQRmLzc_oZ=1_Vf4Q@mail.gmail.com
Backpatch-through: 14
2026-06-04 12:24:51 -04:00
Tom Lane
7bdff3e890 Fix another case of indirectly casting away const.
Like 8f1791c61, this fixes a case of implicitly casting away
const by not treating the result of strrchr() on a const pointer
as const.  This was missed at the time because the machines
reporting those warnings weren't building with --with-llvm.

While here, clean up another infelicity: in the probably-
impossible case that the input string contains only one dot,
this function would call pnstrdup() with a length of -1
and thereby emit a module name equal to the function name.
It seems to me we should emit modname = NULL instead.

Also remove a useless Assert and two redundant assignments.

Back-patch, as 8f1791c61 was, so that users of back branches
don't see this warning when building with late-model gcc.

Reported-by: hubert depesz lubaczewski <depesz@depesz.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/aiGNJ89PBqvq2Yyz@depesz.com
Backpatch-through: 14
2026-06-04 11:37:43 -04:00
Fujii Masao
968c508457 Fix race in ReplicationSlotRelease() for ephemeral slots
When releasing an ephemeral replication slot, ReplicationSlotRelease()
drops the slot via ReplicationSlotDropAcquired().

However, after dropping the slot, ReplicationSlotRelease() continued
to use its local "slot" pointer, which still referenced the dropped
slot's former shared-memory entry. It could then update fields such as
effective_xmin in that entry.

Once an ephemeral slot has been dropped (via ReplicationSlotDropAcquired()),
its slot array entry can be reused immediately by another backend
creating a new slot. As a result, those updates could corrupt
the state of an unrelated replication slot.

Fix by skipping those shared-memory updates for phemeral slots and
performing them only for non-ephemeral slots, whose shared-memory
entries remain valid after release.

Backpatch to all supported versions.

Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: Masao Fujii <masao.fujii@gmail.com>
Reviewed-by: Srinath Reddy Sadipiralla <srinath2133@gmail.com>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
Discussion: https://postgr.es/m/TY4PR01MB177184FF9EE916F577E1F554194082@TY4PR01MB17718.jpnprd01.prod.outlook.com
Backpatch-through: 14
2026-06-03 18:47:52 +09:00
Michael Paquier
74d3482f45 Fix copy-paste error in hash_record_extended()
The code failed to initialize the second isnull argument passed to
FunctionCallInvoke().  This is harmless for existing in-core extended
hash support functions, since FunctionCallInvoke() does not use the
value (note that all the in-core extended hash functions are strict),
examining only the argument values.  However, extension-provided
extended hash functions could be affected if they inspect
PG_ARGISNULL(1).

Oversight in 01e658fa74.

Author: Man Zeng <zengman@halodbtech.com>
Discussion: https://postgr.es/m/tencent_7818173C01E01836109848C3@qq.com
Backpatch-through: 14
2026-06-03 12:47:34 +09:00
Heikki Linnakangas
d616e741fe Use term "referenced" rather than "dependent" in dependency locking
Reported-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://www.postgresql.org/message-id/20260528.114608.488039299811669368.horikyota.ntt@gmail.com
Backpatch-through: 14
2026-05-28 21:29:28 +03:00
Andres Freund
b67b2cd702 Make stack depth check work with asan's use-after-return
With address sanitizer's stack-use-after-return check, stack variables are
moved to heap allocations, to allow to detect references to the memory at a
later time. That broke our stack-depth check, which is why we had to disable
detect_stack_use_after_return in CI. Luckily __builtin_frame_address() works
correctly, even under asan, so use that.

We started using __builtin_frame_address() with de447bb8e6, however as of
that commit we just used it for the stack base address, not for the value to
compare to the base address.  Now we use it for both.

When building without __builtin_frame_address() support, we continue to use
stack variables for the stack depth determination.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/2kk4z4odvuyrg7qlwjd7ft4eron4cle4btb33v4qatgsdkayir@gj6e62rgsel4
Backpatch-through: 14
2026-05-28 11:34:14 -04:00
Heikki Linnakangas
5100bdbd3b Avoid orphaned objects dependencies
Concurrent DDL can leave behind objects referencing other objects that
no longer exist. This can happen if an object is dropped, while a new
object that depends on it is created concurrently. For example:

session 1: BEGIN; CREATE FUNCTION myschema.myfunc() ...;
session 2: DROP SCHEMA myschema;
session 1: COMMIT;

DROP SCHEMA does check that there are no objects dependending on the
schema being dropped, but it does not see objects being concurrently
created by other sessions. Even if it did, this scenario would still
fail:

session 1: BEGIN: DROP SCHEMA myschema;
session 2: CREATE FUNCTION myschema.myfunc() ...;
session 1: COMMIT;

When the DROP SCHEMA runs, the schema was empty, but the new function
is created in it before the dropping transaction completes. The CREATE
FUNCTION does not see that the schema is concurrently being dropped.

In both of these scenarios, the function is left behind in the schema
that no longer exists.

To fix, acquire AccessShareLock on all referenced objects when
recording dependencies. This conflicts with the AccessExclusiveLock
taken by DROP, preventing the race. After acquiring the lock, verify
that the object still exists, and if it was dropped concurrently,
report an error. We already had such a mechanism for shared
dependencies, but for some reason we didn't do it for in-database
dependendies.

Ideally the locks would be acquired much earlier when creating a new
object, but that will require modifying a lot of callers. This check
while recording the dependency is a nice wholesale protection, and
even if we change all the CREATE commands to acquire locks earlier,
it's still good to have this as a backstop to catch any cases where we
forgot to do so.

The patch adds a few tests for some cases that left behind orphaned
objects before this. It also adds a test for roles, which already had
such protection, although that test is partially disabled because the
error message includes an OID which is not predictable.

Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Discussion: https://postgr.es/m/ZiYjn0eVc7pxVY45@ip-10-97-1-34.eu-west-3.compute.internal
Backpatch-through: 14
2026-05-27 18:37:56 +03:00
Heikki Linnakangas
36b6ed2606 Don't try to record dependency on a dropped column's datatype
When creating a relation with a dropped column, we called
recordDependencyOn() also on the datatype of the dropped column, which
is always InvalidOid. In versions 15 and above, that was harmless
because recordDependencyOn() considers InvalidOid as a pinned object,
and skips over it. On version 14, isPinnedObject() does not consider
InvalidOid as pinned, so we created a bogus pg_depend entry with
refobjectid == 0.

As far as I can tell, the only case when AddNewAttributeTuples() is
called with dropped columns is when performing a table-rewriting ALTER
TABLE command. That temporarily creates a new relation with the same
columns, including dropped ones, then swaps the relations, and drops
the newly created table again. So even on version 14, the bogus
pg_depend entry was only on the transient relation that was dropped at
the end of the ALTER TABLE command, which was harmless.

Even though this is harmless, let's be tidy, similar to commit
713bce9484. The reason I noticed this now and why I backported this,
is because the next commit will add code to acquire locks on the
referenced objects, and we don't want to acquire a lock on InvalidOid.

Discussion: https://postgr.es/m/ZiYjn0eVc7pxVY45@ip-10-97-1-34.eu-west-3.compute.internal
Backpatch-through: 14
2026-05-27 18:37:48 +03:00
Heikki Linnakangas
2bb60eb4fe Fix self-deadlock when replaying WAL generated by older minor version
Commit 77dff5d937 introduced a SimpleLruWriteAll() call when replaying
multixact WAL records generated by older minor versions. However,
SimpleLruWriteAll() acquires the SLRU lock and on v16 and below, it's
called while already holding the lock, leading to self-deadlock.
Version 17 and 18 did not have that problem, because in those versions
the lock is acquired later in the function.

To fix, acquire MultiXactOffsetSLRULock later in RecordNewMultiXact(),
at the same place where it's acquired on version 17 and 18.

Author: Andrey Borodin <x4mmm@yandex-team.ru>
Reported-by: Radim Marek <radim@boringsql.com>
Discussion: https://www.postgresql.org/message-id/19490-9c59c6a583513b99@postgresql.org
Backpatch-through: 14-16
2026-05-27 11:50:56 +03:00
Michael Paquier
db4d12fc97 Fix procLatch ownership race in ProcKill()
DisownLatch() was executed after the PGPROC entry of the process
terminated is pushed back into a freelist.  A newly-forked backend that
recycles the slot could call OwnLatch() and PANIC with a "latch already
owned by PID", taking down the server.

There were two scenarios related to lock groups where this issue could
be reached:
* A follower pushes the leader's PGPROC back to the freelist while the
leader has not yet called DisownLatch() in its own ProcKill().
* A leader outliving all its followers pushes its own PGPROC onto the
freelist before reaching DisownLatch(), which would be the most common
scenario.

This issue is fixed by calling SwitchBackToLocalLatch() and
DisownLatch() at an earlier phase of ProcKill(), before any freelist
manipulation happens, so that the slot of the backend terminated is
never exposed as owning a latch.

Note that pgstat_reset_wait_event_storage() is kept at a later stage.
An upcoming commit will take advantage of that by introducing a test
able to check the original PANIC scenario.

Author: Vlad Lesin <vladlesin@gmail.com>
Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/d2983796-2603-41b7-a66e-fc8489ddb954@gmail.com
Backpatch-through: 14
2026-05-27 17:20:00 +09:00
Michael Paquier
8007d11852 Fix race conditions in ProcKill()'s lock-group freelist handling
This commit fixes two bugs in ProcKill()'s lock-group teardown freelist
publication:
* a double push of the leader's PGPROC that corrupts the freelist.
* a leak of the last follower's PGPROC slot.

ProcKill()'s lock-group teardown had two PGPROC freelist updates
scattered through the function, done under two separate freeProcsLock
acquisitions:
* A follower's push of the leader's PGPROC, done when a follower is the
last group member exiting.
* Every backend's self-push at the bottom of the function.

The two freelist updates were coordinated only by inspecting
proc->lockGroupLeader, which a follower could clear as a side effect of
pushing the leader.  This coordination was broken.  For example, with
two concurrent backends:
* The follower clears leader->lockGroupLeader and pushes the leader's
PGPROC under leader_lwlock.
* The follower does not clear its own proc->lockGroupLeader, being
skipped.
* When the leader reaches the bottom of ProcKill(), it sees a NULL
proc->lockGroupLeader (the follower cleared it) and pushes itself,
causing a second dlist_push_tail() of the same node onto the same
freelist.
* The follower at the bottom sees its own proc->lockGroupLeader being
not NULL (never cleared) and skips its own push, causing its own slot
to leak.

This commit refactors the freelist manipulation to be done in two
distinct phases, each step using its own lock acquisition to ensure that
each freelist operation happens in an isolated manner for each backend
(follower or leader):
- First, under a single leader_lwlock acquisition, check the state of
the lock-group.  Depending on if we are dealing with a follower and/or a
leader, and if the leader has exited before a follower, then set some
state booleans that define which actions should be taken with the
freelist.
- Second, under a single freeProcsLock acquisition, perform the cleanup
actions, self-push of a backend and/or push of the leader back to the
freelist.

This is an old issue, dating back to 9.6 where parallel workers and lock
grouping has been added.

Author: Vlad Lesin <vladlesin@gmail.com>
Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/d2983796-2603-41b7-a66e-fc8489ddb954@gmail.com
Backpatch-through: 14
2026-05-27 14:52:31 +09:00
Tom Lane
a96b051a98 Fix missed ReleaseVariableStats() in intarray's _int_matchsel().
Given a WHERE clause like "int[] @@ query_int" or "query_int ~~ int[]"
where the query_int side is a table column having statistics,
_int_matchsel() exited without remembering to free the statistics
tuple.  This would typically lead to warnings about cache refcount
leakage, like
  WARNING:  resource was not closed: cache pg_statistic (73), tuple 42/12 has count 1
It's been wrong since this code was added, in commit c6fbe6d6f.

Bug: #19492
Reported-by: Man Zeng <zengman@halodbtech.com>
Author: Man Zeng <zengman@halodbtech.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19492-ddcd0e22399ef85a@postgresql.org
Backpatch-through: 14
2026-05-25 18:15:49 -04:00
Michael Paquier
7571026673 Fix size check in statext_dependencies_deserialize()
The check for the minimum expected bytea size of a MVDependencies object
was using SizeOfItem() for its calculation.  This macro uses the number
of attributes in a single dependency.

This minimum size calculation should be based on MinSizeOfItems(), that
computes the minimum expected size as the header plus the
minimally-sized number of dependency items.

Oversight in d08c44f7a4.

Author: Ilia Evdokimov <ilya.evdokimov@tantorlabs.com>
Discussion: https://postgr.es/m/4b8d299d-2505-4c30-bf80-0f697410db35@tantorlabs.com
Backpatch-through: 14
2026-05-25 14:39:07 +09:00