1
0
mirror of https://github.com/postgres/postgres.git synced 2026-10-23 13:29:09 +03:00
Commit Graph

4266 Commits

Author SHA1 Message Date
Jacob Champion
e2c48c81fc pgcrypto: Add option to revert to prior decryption behavior
The previous commit raises an ERROR during PGP operations if OpenSSL
does not support the cipher in use. However, any existing messages
created with faulty encryption will no longer be accessible via
pgp_[sym|pub]_decrypt().

To help users out of this situation, add a new ignore-cipher-failure
option which reverts to the broken behavior during decryption only. A
faulty encryption wrapper, created by an OpenSSL configuration that does
not support the cipher, can then be stripped back off by that same
OpenSSL in order to safely reencrypt it. (Note that when OpenSSL does
support the cipher, corrupted messages will not be decrypted regardless
of the ignore-cipher-failure setting; this is unchanged.)

The new tests add a corrupted Blowfish message for both public- and
symmetric-key decryption, resulting in the following test matrix:

- Blowfish supported, default behavior:      fails to decrypt
- Blowfish supported, ignore-cipher-failure: fails to decrypt
- Blowfish unsupported, default behavior:    fails to load cipher
- Blowfish unsupported, ignore-cipher-failure: strips faulty encryption

The previous commit's change to the pubkey tests is expanded similarly:
correctly encrypted messages cannot be decrypted by an OpenSSL that does
not support the cipher, regardless of the option's setting, though the
failure mode will change.

Suggested-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Noah Misch <noah@leadboat.com>
Security: CVE-2026-14663
Backpatch-through: 14
2026-08-10 06:38:37 -07:00
Daniel Gustafsson
7e29eb6f4a Fix errorhandling for PGP encryption
PGP encryption was using px_cipher_encrypt without checking if any
error was returned.  When OpenSSL is running in FIPS mode, or when
the legacy provider hasn't been loaded, not all ciphers which are
supported by the PGP code are available and fail the init step in
px_cipher_encrypt.  Since the PGP encryption failed to notice this
it XORed the non-encrypted block with the plaintext, effectively
disabling the encryption.

This was found due to a report of PGP encryption not respecting
the pgcrypto.builtin_crypto_enabled flag and allowing Blowfish
and DES.  This however turned out to be a false positive, since
the PGP code only use ciphers from OpenSSL and not the built in
ciphers.

Bug: #19457
Reported-by: Shishir Sharma <ansh01072001@gmail.com>
Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Discussion: https://postgr.es/m/19457-4bab15c17aea36c7@postgresql.org
Security: CVE-2026-14663
Backpatch-through: 14
2026-08-10 06:38:37 -07:00
Nathan Bossart
9505175f2a Avoid overflow in Levenshtein distance calculations.
levenshtein() and levenshtein_less_equal() let the caller specify
the insertion, deletion, and substitution costs, and
fuzzystrmatch's corresponding SQL functions accept any 32-bit
integer for each.  Since the distances are calculated with 32-bit
arithmetic, large costs can cause overflows, thereby producing
nonsensical results.  Certain inputs to levenshtein_less_equal()
can even cause out-of-bounds writes.  To fix, use 64-bit arithmetic
instead, and error whenever the final result won't fit in the
returned 32-bit integer.

We may want to teach these functions to reject negative costs, too,
but that didn't seem appropriate for a security fix, and therefore
it is left as a future exercise.

Reported-by: Ben Morris in collaboration with Claude and Anthropic Research
Author: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Security: CVE-2026-15742
Backpatch-through: 14
2026-08-10 06:38:36 -07:00
Jacob Champion
bf3842a64f Add an output_plugin_libraries GUC to bless trusted output plugins
REPLICATION users were not previously subject to restrictions on output
plugin paths, so they were able to bypass LOAD-time protections during
logical decoding. Unfortunately, adding the standard LOAD restrictions
now would retroactively require all third-party output plugins to be
installed under the $libdir/plugins directory. This would prevent the
use of dynamic_library_path, introduce a wire incompatibility for
clients, and require all plugin authors to check that their libraries
are safe for use by any unprivileged user; we want to avoid that.

Instead, introduce an output_plugin_libraries GUC so that DBAs can
specify the output plugins that are trusted for use in logical decoding.
For simplicity, superusers are subject to the restriction as well
(though they're free to modify the GUC at will during a session, so no
power is actually lost).

The default setting is 'pgoutput, test_decoding'. If other third-party
plugins are in use, DBAs will need to modify this parameter after they
update. Some pointers have been added to the documentation to assist
with this.

Author: Jacob Champion <jacob.champion@enterprisedb.com>
Reported-by: Vladimir Tokarev <vladimirelitokarev@gmail.com>
Reported-by: Yu Kunpeng <yu443940816@live.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Backpatch-through: 14
Security: CVE-2026-6471
2026-08-10 06:38:36 -07:00
Noah Misch
39d792040c Empty search_path in amcheck.
A grantee of amcheck function EXECUTE privilege could execute arbitrary
functions as the owners of expression indexes that depend on the search
path.  An expression like (lower(col)) was not vulnerable, because
lower() is resolved at CREATE INDEX time.  However, an expression
calling an sql-language or plpgsql-language function often was
vulnerable, even if it used search_path only to find objects in
pg_catalog.  The amcheck documentation has been warning about data
disclosure after such a GRANT, not about function execution.

This might cause new amcheck errors when index expressions rely on a
broader search_path.  Such indexes have seen errors during auto-analyze
since CVE-2018-1058 commit 582edc369c, and
v17 amcheck always worked this way.  Hence, the risk is low.

Leave a comment on the one other sandbox entrance that doesn't empty
search_path.  In its case, the choice was valid.

Back-patch to v14 (all supported versions), but v17 was safe already.
Commit 2af07e2f74 (v17) unintentionally
blocked the attack, and commit d70b17636d
(v18) unintentionally removed that protection.  Hence, this adds to v17
just a test and a comment.  While emptying search_path became more
widespread in commit 2af07e2f74 (v17),
none of its other changes blocked an attack available in v16, even when
considering GRANT.  For example, brin_summarize_range() has had an owner
check that GRANT does not override.

Reported-by: 王跃林 <violin0613@tju.edu.cn>
Reported-by: Jacob Brazeal <jacob.brazeal@gmail.com>
Backpatch-through: 14
Security: CVE-2026-14673
2026-08-10 06:38:36 -07:00
Heikki Linnakangas
a74aa0854d Fix pg_trgm's picksplit function with all-true datums
The CACHESIGN.sign field is a BITVECP, not a TRGM, so you should not
use GETSIGN() on it. You don't get a compiler warning because the
GETSIGN() macro includes a cast. It resulted in a bogus read beyond
end of buffer, which would cause bad split decisions or a crash if
you're very unlucky.

Reported-by: Mehmet D. INCE <mehmet@mehmetince.net>
Backpatch-through: 14
Security: CVE-2026-14678
2026-08-10 06:38:35 -07:00
Tom Lane
d7fcfead3d Harden PL/Perl code against "tied" Perl arrays and hashes.
Tied arrays might report different sizes each time they are inspected.
To avoid generating a corrupt result array, fix plperl_array_to_datum()
to read av_len() of each input array only once.  If the input does
appear to get shorter, we'll fill nulls for the now-missing entries,
which seems fine.  Conversely, if it gets longer, we'll ignore the new
entries.

plperl_to_hstore() assumed that Perl's hv_iterinit() returns the
number of entries in the given Perl hash.  Usually that's true,
but per the Perl docs, "the return value is currently only meaningful
for hashes without tie magic".  That could potentially end in a memory
stomp.  We don't depend on that result value anywhere else, so don't
do so here either.

Reported-by: Hcamael <baiyjrh@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Andrew Dunstan <andrew@dunslane.net>
Backpatch-through: 14
Security: CVE-2026-14670
2026-08-10 06:38:35 -07:00
Etsuro Fujita
cec48686a0 Drain pending asynchronous requests during ExecReScanAppend.
The logic for asynchronous Append assumes that pending requests made for
subplans of an Append are drained during ExecReScanAppend.  To ensure
that, commit 9e283fc85 modified postgresReScanForeignScan to drain such
a request if any, but failed to take into account that if such a request
was made for a subplan that is re-scanned with parameter changes or
pruned in the next round by runtime pruning, the postgres_fdw callback
function is called after ExecReScanAppend or never called, respectively.
This would cause such a request to remain even after ExecReScanAppend,
leading to incorrect results, an infinite loop, or an assertion failure.

To fix, modify ExecReScanAppend to, for each of the pending requests,
give the FDW a chance to drain that request using the existing
ForeignAsyncConfigureWait/ForeignAsyncNotify callback functions.  This
makes the change made to postgresReScanForeignScan useless, so remove it
as well.

Back-patch to v14 where asynchronous Append was added.

Reported-by: Alexander Korotkov <aekorotkov@gmail.com>
Co-authored-by: Alexander Korotkov <aekorotkov@gmail.com>
Co-authored-by: Gleb Kashkin <g.kashkin@postgrespro.ru>
Co-authored-by: Etsuro Fujita <etsuro.fujita@gmail.com>
Reviewed-by: Alexander Pyhalov <a.pyhalov@postgrespro.ru>
Reviewed-by: Gleb Kashkin <g.kashkin@postgrespro.ru>
Discussion: https://postgr.es/m/CAPpHfduMOTnV5Zj2KGJ7zanL_10QvccZHtPUaDfJvBhsh9axnQ%40mail.gmail.com
Backpatch-through: 14
2026-08-07 17:30:06 +09:00
Álvaro Herrera
e9d53cf459 pg_surgery: Fix infinite loop on large TID arrays
heap_force_common() tracked the current position in the caller-supplied
tid[] using OffsetNumber, which is only 16 bits wide, so when the array
held more than 65535 entries, the updated index wrapped around and the
outer loop never reached the exit condition.  A SQL call with a
sufficiently large TID array would then run until interrupted.

Fix by tracking the tid[] position using int instead of OffsetNumber.
A regress case based on the report is included.

Author: Andrey Rachitskiy <pl0h0yp1@gmail.com>
Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
Reported-by: Yuelin Wang <1217816127@qq.com>
Backpatch-through: 14
Bug: #19607
Discussion: https://postgr.es/m/19607-2f256a66481c514b@postgresql.org
2026-08-04 11:44:11 +02:00
Masahiko Sawada
c2d34db0a5 Fix logical decoding of empty prepared transactions.
A two-phase transaction that is assigned an XID but produces no change
to be decoded -- for example, one that only acquires row locks via
SELECT ... FOR SHARE -- has no base snapshot in the reorder
buffer. ReorderBufferReplay() already skips such a transaction at
PREPARE time and never invokes the begin_prepare/change/prepare
callbacks for it, but ReorderBufferFinishPrepared() still called the
commit_prepared (or rollback_prepared) callback. As a result a
spurious COMMIT/ROLLBACK PREPARED was sent to the output plugin with
no preceding PREPARE. For the built-in subscriber this breaks
replication (the apply worker fails to find the prepared transaction),
and test_decoding could even crash.

Fix this by detecting an empty transaction (base_snapshot == NULL) in
ReorderBufferFinishPrepared() and cleaning it up without invoking the
commit/rollback prepared callbacks, mirroring the existing empty
transaction handling in ReorderBufferReplay().

On v18 and newer versions, commit 072ee847ad changed
ReorderBufferPrepare() to send the prepare whenever it had not already
been sent, which also fires for empty transactions and emits a
spurious PREPARE. On those branches ReorderBufferPrepare() is
therefore additionally guarded with base_snapshot != NULL. This guard
and the Assert(!rbtxn_sent_prepare()) added in
ReorderBufferFinishPrepared(), are not necessary on v17 and older
versions: there ReorderBufferPrepare() only sends a prepare for
concurrently-aborted transactions (which never applies to an empty
transaction) and the RBTXN_SENT_PREPARE flag does not exist.

Back-patch to v14, where decoding of two-phase transactions was
introduced.

Bug: #19556
Reported-by: Alexander Kozhemyakin <a.kozhemyakin@postgrespro.ru>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/19556-daa6d7ea65054d48@postgresql.org
Backpatch-through: 14
2026-07-28 12:33:50 -07:00
Tom Lane
286f9a3cec Fix btree_gist's NotEqual strategy on internal index pages.
gbt_var_consistent() handled the <> (BtreeGistNotEqual) strategy without
distinguishing leaf from internal pages, unlike every other strategy.
In particular, it tried to apply the datatype-specific f_eq method,
which is completely wrong since internal keys might not have the same
representation as leaf keys.  This led to OOB reads and potentially
crashes, and most likely to wrong query results as well.

On leaf pages we can apply the inverse of what the Equal strategy does.
On internal pages, use a correct implementation of what the previous
code intended: we can descend if the query value equals both bounds,
*so long as the bounds aren't truncated*.  With truncated bounds we
don't quite know the range of what's below, so we must always descend.

Adjust the code in gbt_num_consistent() to look similar, too.  This
fixes a performance buglet in that there's no need to do two comparisons
on a leaf entry, but the main point is just to keep code consistency.

Reported-by: 王跃林 <violin0613@tju.edu.cn>
Author: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/AH*AvQCYKhQGVvPWi1GiU4oY.8.1781609375063.Hmail.3020001251@tju.edu.cn
Backpatch-through: 14
2026-07-03 13:50:14 -04:00
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
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
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
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
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
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
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
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
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
092b570a72 Re-add regression tests for ltree and intarray
These tests have been removed by 906ea101d0, due to some of them being
unstable in the buildfarm with low max_stack_depth values.  They are now
reworked so as they should be more portable.

The tests to cover the findoprnd() overflows use a balanced tree to
avoid using too much stack, per a suggestion and an investigation by Tom
Lane.

Note: This is initially applied only on HEAD; a backpatch will follow
should the buildfarm be fine with the situation.

Discussion: https://postgr.es/m/agZc6XecyE7E7fep@paquier.xyz
Backpatch-through: 14
2026-05-15 18:02:54 +09:00
Nathan Bossart
1de0a711db refint: Fix segfault in check_foreign_key().
When an UPDATE statement triggers check_foreign_key() with the
action set to "cascade", it generates more UPDATE statements to
modify the key values in referencing relations.  If a new key value
is NULL, SPI_getvalue() returns a NULL pointer, which is
subsequently passed to quote_literal_cstr(), causing a segfault.
To fix, skip quoting when a new key value is NULL and insert an
unquoted NULL keyword instead.

Oversight in commit 260e97733b.  While the refint documentation
recommends marking primary key columns NOT NULL, the aforementioned
scenario accidentally worked on platforms where snprintf()
substitutes "(null)" for NULL pointers.  Note that for
character-type columns, the old code quoted "(null)" as a string
literal, so this didn't always produce correct results.  But it
still seems better to fix this than to reject cases that previously
worked.

Reported-by: Nikita Kalinin <n.kalinin@postgrespro.ru>
Author: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Reviewed-by: Pierre Forstmann <pierre.forstmann@gmail.com>
Discussion: https://postgr.es/m/19476-bd04ea6241345303%40postgresql.org
Backpatch-through: 14
2026-05-14 13:11:49 -05:00
Heikki Linnakangas
c9447b8bd0 Use palloc_array() in a few more places to avoid overflow
These could overflow on 32-bit systems.

Backpatch-through: 14
Security: CVE-2026-6473
2026-05-11 21:29:27 +03:00
Tom Lane
479823a710 Remove test cases for field overflows in intarray and ltree.
These checks are failing in the buildfarm, reporting stack overflows
rather than the expected errors, though seemingly only on ppc64 and
s390x platforms.  Perhaps there is something off about our tests
for stack depth on those architectures?  But there's no time to
debug that right now, and surely these tests aren't too essential.
Revert for now and plan to revisit after the release dust settles.

Backpatch-through: 14
Security: CVE-2026-6473
2026-05-11 12:12:03 -04:00
Nathan Bossart
2b026df29c refint: Fix SQL injection and buffer overruns.
Maliciously crafted key value updates could achieve SQL injection
within check_foreign_key().  To fix, ensure new key values are
properly quoted and escaped in the internally generated SQL
statements.  While at it, avoid potential buffer overruns by
replacing the stack buffers for internally generated SQL statements
with StringInfo.

Reported-by: Nikolay Samokhvalov <nik@postgres.ai>
Author: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Security: CVE-2026-6637
Backpatch-through: 14
2026-05-11 05:13:52 -07:00
Tom Lane
0747025259 Guard against overflow in "left" fields of query_int and ltxtquery.
contrib/intarray's query_int type uses an int16 field to hold the
offset from a binary operator node to its left operand.  However, it
allows the number of nodes to be as much as will fit in MaxAllocSize,
so there is a risk of overflowing int16 depending on the precise shape
of the tree.  Simple right-associative cases like "a | b | c | ..."
work fine, so we should not solve this by restricting the overall
number of nodes.  Instead add a direct test of whether each individual
offset is too large.

contrib/ltree's ltxtquery type uses essentially the same logic and
has the same 16-bit restriction.

(The core backend's tsquery.c has a variant of this logic too, but
in that case the target field is 32 bits, so it is okay so long
as varlena datums are restricted to 1GB.)

In v16 and up, these types support soft error reporting, so we have
to complicate the recursive findoprnd function's API a bit to allow
the complaint to be reported softly.  v14/v15 don't need that.

Undocumented and overcomplicated code like this makes my head hurt,
so add some comments and simplify while at it.

Reported-by: Xint Code
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Backpatch-through: 14
Security: CVE-2026-6473
2026-05-11 05:13:51 -07:00
Michael Paquier
b545c37876 ltree: Fix overflows with lquery parsing
The lquery parser in contrib/ltree/ had two overflow problems:
- A single lquery level with many OR-separated variants (e.g.,
'label1|label2|...'), could cause an overflow of totallen, this being
stored as a uint16, meaning a maximum value of UINT16_MAX or 65k.  Each
variant contributes MAXALIGN(LVAR_HDRSIZE + len) bytes.  With enough
long variants, the value would wraparound.  This would corrupt the data
written by LQL_NEXT(), leading to a stack corruption, most likely
translating into a crash, but it would allow incorrect memory access.
- numvar, labelled as a uint16, counts the number of OR-variants in a
single level, and it is incremented without bounds checking.  With more
than PG_UINT16_MAX (65k) variants in a single level, and a minimum of
131kB of input data, it would wrap to 0.  When a (wildcard) '*' is
used, this would change the query results silently.

For both issues, a set of overflows checks are added to guard against
these problematic patterns.

The first issue has been reported by the three people listed below,
affecting v16 and newer versions due to b1665bf01e.  Its coding was
still unsafe in v14 and v15.  The second issue affects all the stable
branches; I have bumped into while reviewing the code of the module.

Reported-by: Vergissmeinnicht <vergissmeinnichtzh@gmail.com>
Reported-by: A1ex <alex000young@gmail.com>
Reported-by: Jihe Wang <wangjihe.mail@gmail.com>
Author: Michael Paquier <michael@paquier.xyz>
Security: CVE-2026-6473
Backpatch-through: 14
2026-05-11 05:13:51 -07:00
Etsuro Fujita
fd5b36ab18 postgres_fdw: Fix handling of abort-cleanup-failed connections.
As connections that failed abort cleanup can't safely be further used,
if a remote query tries to get such a connection, we reject it.
Previously, this rejection involved dropping the connection if it was
open, without accounting for the possibility of open cursors using it,
causing a server crash when such an open cursor tried to use an
already-dropped connection, as a cursor-handling function
(create_cursor, fetch_more_data, or close_cursor) was called on a freed
PGconn.  To fix, delay dropping failed connections until abort cleanup
of the main transaction, to ensure open cursors using such a connection
can safely refer to the PGconn for it.

Oversight in commit 8bf58c0d9.

Reported-by: Zhibai Song <songzhibai1234@gmail.com>
Diagnosed-by: Zhibai Song <songzhibai1234@gmail.com>
Author: Etsuro Fujita <etsuro.fujita@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Matheus Alcantara <matheusssilv97@gmail.com>
Discussion: https://postgr.es/m/CAPmGK176y6JP017-Cn%2BhS9CEJx_6iVhRoYbAqzuLU4d8-XPPNg%40mail.gmail.com
Backpatch-through: 14
2026-05-05 18:55:06 +09:00
Heikki Linnakangas
a6d03067ff Avoid memory leak on error while parsing pg_stat_statements dump file
By using palloc() instead of raw malloc().

Reported-by: Gaurav Singh <gaurav.singh@yugabyte.com>
Reviewed-by: Lukas Fittl <lukas@fittl.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://www.postgresql.org/message-id/CAEcQ1bYR9s4eQLFDjzzJHU8fj-MTbmRpW-9J-r2gsCn+HEsynw@mail.gmail.com
Backpatch-through: 14
2026-03-27 12:23:38 +02:00
Michael Paquier
70f7c5badc xml2: Fix failure with xslt_process() under -fsanitize=undefined
The logic of xslt_process() has never considered the fact that
xsltSaveResultToString() would return NULL for an empty string (the
upstream code has always done so, with a string length of 0).  This
would cause memcpy() to be called with a NULL pointer, something
forbidden by POSIX.

Like 46ab07ffda and similar fixes, this is backpatched down to all the
supported branches, with a test case to cover this scenario.  An empty
string has been always returned in xml2 in this case, based on the
history of the module, so this is an old issue.

Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/c516a0d9-4406-47e3-9087-5ca5176ebcf9@gmail.com
Backpatch-through: 14
2026-03-13 16:06:51 +09:00
Etsuro Fujita
e72bde9017 postgres_fdw: Fix thinko in comment for UserMappingPasswordRequired().
This commit also rephrases this comment to improve readability.

Oversight in commit 6136e94dc.

Reported-by: Etsuro Fujita <etsuro.fujita@gmail.com>
Author: Andreas Karlsson <andreas@proxel.se>
Co-authored-by: Etsuro Fujita <etsuro.fujita@gmail.com>
Discussion: https://postgr.es/m/CAPmGK16pDnM_wU3kmquPj-M9MYqG3y0BdntRZ0eytqbCaFY3WQ%40mail.gmail.com
Backpatch-through: 14
2026-02-27 17:05:06 +09:00
Jeff Davis
058710d415 Fix more multibyte issues in ltree.
Commit 84d5efa7e3 missed some multibyte issues caused by short-circuit
logic in the callers. The callers assumed that if the predicate string
is longer than the label string, then it couldn't possibly be a match,
but it can be when using case-insensitive matching (LVAR_INCASE) if
casefolding changes the byte length.

Fix by refactoring to get rid of the short-circuit logic as well as
the function pointer, and consolidate the logic in a replacement
function ltree_label_match().

Discussion: https://postgr.es/m/02c6ef6cf56a5013ede61ad03c7a26affd27d449.camel@j-davis.com
Backpatch-through: 14
2026-02-26 12:26:32 -08:00
Michael Paquier
f604cc695c hstore: Fix NULL pointer dereference with receive function
The receive function of hstore was not able to handle correctly
duplicate key values when a new duplicate links to a NULL value, where a
pfree() could be attempted on a NULL pointer, crashing due to a pointer
dereference.

This problem would happen for a COPY BINARY, when stacking values like
that:
aa => 5
aa => null

The second key/value pair is discarded and pfree() calls are attempted
on its key and its value, leading to a pointer dereference for the value
part as the value is NULL.  The first key/value pair takes priority when
a duplicate is found.

Per offline report.

Reported-by: "Anemone" <vergissmeinnichtzh@gmail.com>
Reported-by: "A1ex" <alex000young@gmail.com>
Backpatch-through: 14
2026-02-17 08:41:37 +09:00
Michael Paquier
c60a582044 pgcrypto: Tweak error message for incorrect session key length
The error message added in 379695d3cc referred to the public key being
too long.  This is confusing as it is in fact the session key included
in a PGP message which is too long.  This is harmless, but let's be
precise about what is wrong.

Per offline report.

Reported-by: Zsolt Parragi <zsolt.parragi@percona.com>
Backpatch-through: 14
2026-02-16 12:18:34 +09:00
Tom Lane
ec9f0cbe01 Further stabilize a postgres_fdw test case.
The buildfarm occasionally shows a variant row order in the output
of this UPDATE ... RETURNING, implying that the preceding INSERT
dropped one of the rows into some free space within the table rather
than appending them all at the end.  It's not entirely clear why that
happens some times and not other times, but we have established that
it's affected by concurrent activity in other databases of the
cluster.  In any case, the behavior is not wrong; the test is at fault
for presuming that a seqscan will give deterministic row ordering.
Add an ORDER BY atop the update to stop the buildfarm noise.

The buildfarm seems to have shown this only in v18 and master
branches, but just in case the cause is older, back-patch to
all supported branches.

Discussion: https://postgr.es/m/3866274.1770743162@sss.pgh.pa.us
Backpatch-through: 14
2026-02-11 11:03:01 -05:00
Noah Misch
5301b2b7de Fix test "NUL byte in text decrypt" for --without-zlib builds.
Backpatch-through: 14
Security: CVE-2026-2006
2026-02-09 09:08:14 -08:00
Tom Lane
7e82d9a04d 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
Noah Misch
8373ed0944 Require PGP-decrypted text to pass encoding validation.
pgp_sym_decrypt() and pgp_pub_decrypt() will raise such errors, while
bytea variants will not.  The existing "dat3" test decrypted to non-UTF8
text, so switch that query to bytea.

The long-term intent is for type "text" to always be valid in the
database encoding.  pgcrypto has long been known as a source of
exceptions to that intent, but a report about exploiting invalid values
of type "text" brought this module to the forefront.  This particular
exception is straightforward to fix, with reasonable effect on user
queries.  Back-patch to v14 (all supported versions).

Reported-by: Paul Gerste (as part of zeroday.cloud)
Reported-by: Moritz Sanft (as part of zeroday.cloud)
Author: shihao zhong <zhong950419@gmail.com>
Reviewed-by: cary huang <hcary328@gmail.com>
Discussion: https://postgr.es/m/CAGRkXqRZyo0gLxPJqUsDqtWYBbgM14betsHiLRPj9mo2=z9VvA@mail.gmail.com
Backpatch-through: 14
Security: CVE-2026-2006
2026-02-09 06:14:52 -08:00
Thomas Munro
e7591254c3 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 12:39:16 +13:00
Thomas Munro
cecedb912a 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 12:39:01 +13:00
Michael Paquier
01de2e32df pgcrypto: Fix buffer overflow in pgp_pub_decrypt_bytea()
pgp_pub_decrypt_bytea() was missing a safeguard for the session key
length read from the message data, that can be given in input of
pgp_pub_decrypt_bytea().  This can result in the possibility of a buffer
overflow for the session key data, when the length specified is longer
than PGP_MAX_KEY, which is the maximum size of the buffer where the
session data is copied to.

A script able to rebuild the message and key data that can trigger the
overflow is included in this commit, based on some contents provided by
the reporter, heavily editted by me.  A SQL test is added, based on the
data generated by the script.

Reported-by: Team Xint Code as part of zeroday.cloud
Author: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Noah Misch <noah@leadboat.com>
Security: CVE-2026-2005
Backpatch-through: 14
2026-02-09 08:01:12 +09:00
John Naylor
fc56793c9a 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
Amit Langote
6d2fa44d2a 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 10:23:10 +09:00
Álvaro Herrera
607a67c5e6 amcheck: Fix snapshot usage in bt_index_parent_check
We were using SnapshotAny to do some index checks, but that's wrong and
causes spurious errors when used on indexes created by CREATE INDEX
CONCURRENTLY.  Fix it to use an MVCC snapshot, and add a test for it.

Backpatch of 6bd469d26a to branches 14-16.  I previously misidentified
the bug's origin: it came in with commit 7f563c09f8 (pg11-era, not
5ae2087202 as claimed previously), so all live branches are affected.

Also take the opportunity to fix some comments that we failed to update
in the original commits and apply pgperltidy.  In branch 14, remove the
unnecessary test plan specification (which would have need to have been
changed anyway; c.f. commit 549ec201d613.)

Diagnosed-by: Donghang Lin <donghanglin@gmail.com>
Author: Mihail Nikalayeu <mihailnikalayeu@gmail.com>
Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
Backpatch-through: 17
Discussion: https://postgr.es/m/CANtu0ojmVd27fEhfpST7RG2KZvwkX=dMyKUqg0KM87FkOSdz8Q@mail.gmail.com
2026-01-21 18:55:43 +01:00
David Rowley
67a6fd5074 Fix selectivity estimation integer overflow in contrib/intarray
This fixes a poorly written integer comparison function which was
performing subtraction in an attempt to return a negative value when
a < b and a positive value when a > b, and 0 when the values were equal.
Unfortunately that didn't always work correctly due to two's complement
having the INT_MIN 1 further from zero than INT_MAX.  This could result
in an overflow and cause the comparison function to return an incorrect
result, which would result in the binary search failing to find the
value being searched for.

This could cause poor selectivity estimates when the statistics stored
the value of INT_MAX (2147483647) and the value being searched for was
large enough to result in the binary search doing a comparison with that
INT_MAX value.

Author: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/CAEoWx2ng1Ot5LoKbVU-Dh---dFTUZWJRH8wv2chBu29fnNDMaQ@mail.gmail.com
Backpatch-through: 14
2026-01-04 20:34:45 +13:00
Jeff Davis
898991966b Fix multibyte issue in ltree_strncasecmp().
Previously, the API for ltree_strncasecmp() took two inputs but only
one length (that of the smaller input). It truncated the larger input
to that length, but that could break a multibyte sequence.

Change the API to be a check for prefix equality (possibly
case-insensitive) instead, which is all that's needed by the
callers. Also, provide the lengths of both inputs.

Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/5f65b85740197ba6249ea507cddf609f84a6188b.camel%40j-davis.com
Backpatch-through: 14
2025-12-16 10:38:15 -08:00