Release date: 2023-11-09
This release contains a variety of fixes from 16.0. For information about new features in major release 16, see Section E.5.
A dump/restore is not required for those running 16.X.
However, several mistakes have been discovered that could lead to
certain types of indexes yielding wrong search results or being
unnecessarily inefficient. It is advisable
to REINDEX
potentially-affected indexes after
installing this update. See the fourth through seventh changelog
entries below.
Fix handling of unknown-type arguments
in DISTINCT
"any"
aggregate
functions (Tom Lane)
This error led to a text
-type value being interpreted
as an unknown
-type value (that is, a zero-terminated
string) at runtime. This could result in disclosure of server
memory following the text
value.
The PostgreSQL Project thanks Jingzhou Fu for reporting this problem. (CVE-2023-5868)
Detect integer overflow while computing new array dimensions (Tom Lane)
When assigning new elements to array subscripts that are outside the current array bounds, an undetected integer overflow could occur in edge cases. Memory stomps that are potentially exploitable for arbitrary code execution are possible, and so is disclosure of server memory.
The PostgreSQL Project thanks Pedro Gallegos for reporting this problem. (CVE-2023-5869)
Prevent the pg_signal_backend
role from
signalling background workers and autovacuum processes
(Noah Misch, Jelte Fennema-Nio)
The documentation says that pg_signal_backend
cannot issue signals to superuser-owned processes. It was able to
signal these background processes, though, because they advertise a
role OID of zero. Treat that as indicating superuser ownership.
The security implications of cancelling one of these process types
are fairly small so far as the core code goes (we'll just start
another one), but extensions might add background workers that are
more vulnerable.
Also ensure that the is_superuser
parameter is
set correctly in such processes. No specific security consequences
are known for that oversight, but it might be significant for some
extensions.
The PostgreSQL Project thanks Hemanth Sandrana and Mahendrakar Srinivasarao for reporting this problem. (CVE-2023-5870)
Fix misbehavior during recursive page split in GiST index build (Heikki Linnakangas)
Fix a case where the location of a page downlink was incorrectly tracked, and introduce some logic to allow recovering from such situations rather than silently doing the wrong thing. This error could result in incorrect answers from subsequent index searches. It may be advisable to reindex all GiST indexes after installing this update.
Prevent de-duplication of btree index entries
for interval
columns (Noah Misch)
There are interval
values that are distinguishable but
compare equal, for example 24:00:00
and 1 day
. This breaks assumptions made by btree
de-duplication, so interval
columns need to be excluded
from de-duplication. This oversight can cause incorrect results
from index-only scans. Moreover, after
updating amcheck will report an error for
almost all such indexes. Users should reindex any btree indexes
on interval
columns.
Process date
values more sanely in
BRIN datetime_minmax_multi_ops
indexes
(Tomas Vondra)
The distance calculation for dates was backward, causing poor
decisions about which entries to merge. The index still produces
correct results, but is much less efficient than it should be.
Reindexing BRIN minmax_multi
indexes
on date
columns is advisable.
Process large timestamp
and timestamptz
values more sanely in
BRIN datetime_minmax_multi_ops
indexes
(Tomas Vondra)
Infinities were mistakenly treated as having distance zero rather
than a large distance from other values, causing poor decisions
about which entries to merge. Also, finite-but-very-large values
(near the endpoints of the representable timestamp range) could
result in internal overflows, again causing poor decisions. The
index still produces correct results, but is much less efficient
than it should be. Reindexing BRIN minmax_multi
indexes on timestamp
and timestamptz
columns is advisable if the column contains, or has contained,
infinities or large finite values.
Avoid calculation overflows in
BRIN interval_minmax_multi_ops
indexes with
extreme interval values (Tomas Vondra)
This bug might have caused unexpected failures while trying to insert large interval values into such an index.
Fix partition step generation and runtime partition pruning for hash-partitioned tables with multiple partition keys (David Rowley)
Some cases involving an IS NULL
condition on one
of the partition keys could result in a crash.
Fix inconsistent rechecking of concurrently-updated rows
during MERGE
(Dean Rasheed)
In READ COMMITTED
mode, an update that finds that
its target row was just updated by a concurrent transaction will
recheck the query's WHERE
conditions on the
updated row. MERGE
failed to ensure that the
proper rows of other joined tables were used during this recheck,
possibly resulting in incorrect decisions about whether the
newly-updated row should be updated again
by MERGE
.
Correctly identify the target table in an
inherited UPDATE
/DELETE
/MERGE
even when the parent table is excluded by constraints (Amit Langote,
Tom Lane)
If the initially-named table is excluded by constraints, but not all its inheritance descendants are, the first non-excluded descendant was identified as the primary target table. This would lead to firing statement-level triggers associated with that table, rather than the initially-named table as should happen. In v16, the same oversight could also lead to « invalid perminfoindex 0 in RTE with relid NNNN » errors.
Fix edge case in btree mark/restore processing of ScalarArrayOpExpr clauses (Peter Geoghegan)
When restoring an indexscan to a previously marked position, the
code could miss required setup steps if the scan had advanced
exactly to the end of the matches for a ScalarArrayOpExpr (that is,
an indexcol = ANY(ARRAY[])
) clause. This could
result in missing some rows that should have been fetched.
Fix intra-query memory leak in Memoize execution (Orlov Aleksej, David Rowley)
Fix intra-query memory leak when a set-returning function repeatedly returns zero rows (Tom Lane)
Don't crash if cursor_to_xmlschema()
is applied
to a non-data-returning Portal (Boyu Yang)
Fix improper sharing of origin filter condition across
successive pg_logical_slot_get_changes()
calls
(Hou Zhijie)
The origin condition set by one call of this function would be re-used by later calls that did not specify the origin argument. This was not intended.
Throw the intended error if pgrowlocks()
is
applied to a partitioned table (David Rowley)
Previously, a not-on-point complaint « only heap AM is supported » would be raised.
Handle invalid indexes more cleanly in assorted SQL functions (Noah Misch)
Report an error if pgstatindex()
,
pgstatginindex()
,
pgstathashindex()
,
or pgstattuple()
is applied to an invalid
index. If brin_desummarize_range()
,
brin_summarize_new_values()
,
brin_summarize_range()
,
or gin_clean_pending_list()
is applied to an
invalid index, do nothing except to report a debug-level message.
Formerly these functions attempted to process the index, and might
fail in strange ways depending on what the failed CREATE
INDEX
had left behind.
Avoid premature memory allocation failure with long inputs
to to_tsvector()
(Tom Lane)
Fix over-allocation of the constructed tsvector
in tsvectorrecv()
(Denis Erokhin)
If the incoming vector includes position data, the binary receive
function left wasted space (roughly equal to the size of the
position data) in the finished tsvector
. In extreme
cases this could lead to « maximum total lexeme length
exceeded » failures for vectors that were under the length
limit when emitted. In any case it could lead to wasted space
on-disk.
Improve checks for corrupt PGLZ compressed data (Flavien Guedez)
Fix ALTER SUBSCRIPTION
so that a commanded change
in the run_as_owner
option is actually applied
(Hou Zhijie)
Fix bulk table insertion into partitioned tables (Andres Freund)
Improper sharing of insertion state across partitions could result
in failures during COPY FROM
, typically
manifesting as « could not read block NNNN in file XXXX: read
only 0 of 8192 bytes » errors.
In COPY FROM
, avoid evaluating column default
values that will not be needed by the command (Laurenz Albe)
This avoids a possible error if the default value isn't actually valid for the column, or if the default's expression would fail in the current execution context. Such edge cases sometimes arise while restoring dumps, for example. Previous releases did not fail in this situation, so prevent v16 from doing so.
In COPY FROM
, fail cleanly when an unsupported
encoding conversion is needed (Tom Lane)
Recent refactoring accidentally removed the intended error check for this, such that it ended in « cache lookup failed for function 0 » instead of a useful error message.
Avoid crash in EXPLAIN
if a parameter marked to
be displayed by EXPLAIN
has a NULL boot-time
value (Xing Guo, Aleksander Alekseev, Tom Lane)
No built-in parameter fits this description, but an extension could define such a parameter.
Ensure we have a snapshot while dropping ON COMMIT
DROP
temp tables (Tom Lane)
This prevents possible misbehavior if any catalog entries for the
temp tables have fields wide enough to require toasting (such as a
very complex CHECK
condition).
Avoid improper response to shutdown signals in child processes
just forked by system()
(Nathan Bossart)
This fix avoids a race condition in which a child process that has
been forked off by system()
, but hasn't yet
exec'd the intended child program, might receive and act on a signal
intended for the parent server process. That would lead to
duplicate cleanup actions being performed, which will not end well.
Cope with torn reads of pg_control
in frontend
programs (Thomas Munro)
On some file systems, reading pg_control
may
not be an atomic action when the server concurrently writes that
file. This is detectable via a bad CRC. Retry a few times to see
if the file becomes valid before we report error.
Avoid torn reads of pg_control
in relevant SQL
functions (Thomas Munro)
Acquire the appropriate lock before
reading pg_control
, to ensure we get a
consistent view of that file.
Fix « could not find pathkey item to sort » errors
occurring while planning aggregate functions with ORDER
BY
or DISTINCT
options (David Rowley)
Avoid integer overflow when computing size of backend activity string array (Jakub Wartak)
On 64-bit machines we will allow values
of track_activity_query_size
large enough to
cause 32-bit overflow when multiplied by the allowed number of
connections. The code actually allocating the per-backend local
array was careless about this though, and allocated the array
incorrectly.
Fix briefly showing inconsistent progress statistics
for ANALYZE
on inherited tables
(Heikki Linnakangas)
The block-level counters should be reset to zero at the same time we update the current-relation field.
Fix the background writer to report any WAL writes it makes to the statistics counters (Nazir Bilal Yavuz)
Fix confusion about forced-flush behavior
in pgstat_report_wal()
(Ryoga Yoshida, Michael Paquier)
This could result in some statistics about WAL I/O being forgotten in a shutdown.
Fix statistics tracking of temporary-table extensions (Karina Litskevich, Andres Freund)
These were counted as normal-table writes when they should be counted as temp-table writes.
When track_io_timing
is enabled, include the
time taken by relation extension operations as write time
(Nazir Bilal Yavuz)
Track the dependencies of cached CALL
statements,
and re-plan them when needed (Tom Lane)
DDL commands, such as replacement of a function that has been
inlined into a CALL
argument, can create the need
to re-plan a CALL
that has been cached by
PL/pgSQL. That was not happening, leading to misbehavior or strange
errors such as « cache lookup failed ».
Avoid a possible pfree-a-NULL-pointer crash after an error in OpenSSL connection setup (Sergey Shinderuk)
Track nesting depth correctly when
inspecting RECORD
-type Vars from outer query levels
(Richard Guo)
This oversight could lead to assertion failures, core dumps, or « bogus varno » errors.
Track hash function and negator function dependencies of ScalarArrayOpExpr plan nodes (David Rowley)
In most cases this oversight was harmless, since these functions would be unlikely to disappear while the node's original operator remains present.
Fix error-handling bug in RECORD
type cache management
(Thomas Munro)
An out-of-memory error occurring at just the wrong point could leave behind inconsistent state that would lead to an infinite loop.
Treat out-of-memory failures as fatal while reading WAL (Michael Paquier)
Previously this would be treated as a bogus-data condition, leading to the conclusion that we'd reached the end of WAL, which is incorrect and could lead to inconsistent WAL replay.
Fix possible recovery failure due to trying to allocate memory based on a bogus WAL record length field (Thomas Munro, Michael Paquier)
Fix « could not duplicate handle » error occurring on
Windows when min_dynamic_shared_memory
is set
above zero (Thomas Munro)
Fix order of operations in GenericXLogFinish
(Jeff Davis)
This code violated the conditions required for crash safety by
writing WAL before marking changed buffers dirty. No core code uses
this function, but extensions do (contrib/bloom
does, for example).
Remove incorrect assertion in PL/Python exception handling (Alexander Lakhin)
Fix pg_dump to dump the
new run_as_owner
option of subscriptions
(Philip Warner)
Due to this oversight, subscriptions would always be restored
with run_as_owner
set
to false
, which is not equivalent to their
behavior in pre-v16 releases.
Fix pg_restore so that selective restores will include both table-level and column-level ACLs for selected tables (Euler Taveira, Tom Lane)
Formerly, only the table-level ACL would get restored if both types were present.
Add logic to pg_upgrade to check for use
of abstime
, reltime
,
and tinterval
data types (Álvaro Herrera)
These obsolete data types were removed in PostgreSQL version 12, so check to make sure they aren't present in an older database before claiming it can be upgraded.
Avoid false « too many client connections » errors in pgbench on Windows (Noah Misch)
Fix vacuumdb's handling of
multiple -N
switches (Nathan Bossart, Kuwamura
Masaki)
Multiple -N
switches should exclude tables
in multiple schemas, but in fact excluded nothing due to faulty
construction of a generated query.
Fix vacuumdb to honor
its --buffer-usage-limit
option in analyze-only
mode (Ryoga Yoshida, David Rowley)
In contrib/amcheck
, do not report interrupted
page deletion as corruption (Noah Misch)
This fix prevents false-positive reports of « the first child
of leftmost target page is not leftmost of its
level », « block NNNN is not leftmost »
or « left link/right link pair in index XXXX not in
agreement ». They appeared
if amcheck ran after an unfinished btree
index page deletion and before VACUUM
had cleaned
things up.
Fix failure of contrib/btree_gin
indexes
on interval
columns,
when an indexscan using the <
or <=
operator is performed (Dean Rasheed)
Such an indexscan failed to return all the entries it should.
Add support for LLVM 16 and 17 (Thomas Munro, Dmitry Dolgov)
Suppress assorted build-time warnings on recent macOS (Tom Lane)
Xcode 15 (released
with macOS Sonoma) changed the linker's
behavior in a way that causes many duplicate-library warnings while
building PostgreSQL. These were
harmless, but they're annoying so avoid citing the same libraries
twice. Also remove use of the -multiply_defined
suppress
linker switch, which apparently has been a no-op
for a long time, and is now actively complained of.
When building contrib/unaccent
's rules file,
fall back to using python
if --with-python
was not given and make
variable PYTHON
was not set (Japin Li)
Remove PHOT
(Phoenix Islands Time) from the
default timezone abbreviations list (Tom Lane)
Presence of this abbreviation in the default list can cause failures on recent Debian and Ubuntu releases, as they no longer install the underlying tzdb entry by default. Since this is a made-up abbreviation for a zone with a total human population of about two dozen, it seems unlikely that anyone will miss it. If someone does, they can put it back via a custom abbreviations file.