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2025-05-23Fix AlignedAllocRealloc to cope sanely with OOM.Tom Lane
If the inner allocation call returns NULL, we should restore the previous state and return NULL. Previously this code pfree'd the old chunk anyway, which is surely wrong. Also, make it call MemoryContextAllocationFailure rather than summarily returning NULL. The fact that we got control back from the inner call proves that MCXT_ALLOC_NO_OOM was passed, so this change is just cosmetic, but someday it might be less so. This is just a latent bug at present: AFAICT no in-core callers use this function at all, let alone call it with MCXT_ALLOC_NO_OOM. Still, it's the kind of bug that might bite back-patched code pretty hard someday, so let's back-patch to v17 where the bug was introduced (by commit 743112a2e). Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/285483.1746756246@sss.pgh.pa.us Backpatch-through: 17
2025-05-22Fix memory leak in XMLSERIALIZE(... INDENT).Tom Lane
xmltotext_with_options sometimes tries to replace the existing root node of a libxml2 document. In that case xmlDocSetRootElement will unlink and return the old root node; if we fail to free it, it's leaked for the remainder of the session. The amount of memory at stake is not large, a couple hundred bytes per occurrence, but that could still become annoying in heavy usage. Our only other xmlDocSetRootElement call is not at risk because it's working on a just-created document, but let's modify that code too to make it clear that it's dependent on that. Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Jim Jones <jim.jones@uni-muenster.de> Discussion: https://postgr.es/m/1358967.1747858817@sss.pgh.pa.us Backpatch-through: 16
2025-05-19Fix deparsing FETCH FIRST <expr> ROWS WITH TIESHeikki Linnakangas
In the grammar, <expr> is a c_expr, which accepts only a limited set of integer literals and simple expressions without parens. The deparsing logic didn't quite match the grammar rule, and failed to use parens e.g. for "5::bigint". To fix, always surround the expression with parens. Would be nice to omit the parens in simple cases, but unfortunately it's non-trivial to detect such simple cases. Even if the expression is a simple literal 123 in the original query, after parse analysis it becomes a FuncExpr with COERCE_IMPLICIT_CAST rather than a simple Const. Reported-by: yonghao lee Backpatch-through: 13 Discussion: https://www.postgresql.org/message-id/18929-077d6b7093b176e2@postgresql.org
2025-05-11Fix comment of tsquerysend()Álvaro Herrera
The comment describes the order in which fields are sent, and it had one of the fields in the wrong place. This has been wrong since e6dbcb72fafa (2008), so backpatch all the way back. Author: Emre Hasegeli <emre@hasegeli.com> Discussion: https://postgr.es/m/CAE2gYzzf38bR_R=izhpMxAmqHXKeM5ajkmukh4mNs_oXfxcMCA@mail.gmail.com
2025-05-10Fix incorrect "return NULL" in BumpAllocLarge().Tom Lane
This must be "return MemoryContextAllocationFailure(context, size, flags)" instead. The effect of this oversight is that if we got a malloc failure right here, the code would act as though MCXT_ALLOC_NO_OOM had been specified, whether it was or not. That would likely lead to a null-pointer-dereference crash at the unsuspecting call site. Noted while messing with a patch to improve our Valgrind leak detection support. Back-patch to v17 where this code came in.
2025-05-05With GB18030, prevent SIGSEGV from reading past end of allocation.Noah Misch
With GB18030 as source encoding, applications could crash the server via SQL functions convert() or convert_from(). Applications themselves could crash after passing unterminated GB18030 input to libpq functions PQescapeLiteral(), PQescapeIdentifier(), PQescapeStringConn(), or PQescapeString(). Extension code could crash by passing unterminated GB18030 input to jsonapi.h functions. All those functions have been intended to handle untrusted, unterminated input safely. A crash required allocating the input such that the last byte of the allocation was the last byte of a virtual memory page. Some malloc() implementations take measures against that, making the SIGSEGV hard to reach. Back-patch to v13 (all supported versions). Author: Noah Misch <noah@leadboat.com> Author: Andres Freund <andres@anarazel.de> Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com> Backpatch-through: 13 Security: CVE-2025-4207
2025-05-03Fix typos in comments.Etsuro Fujita
Also adjust the phrasing in the comments. Author: Etsuro Fujita <etsuro.fujita@gmail.com> Author: Heikki Linnakangas <hlinnaka@iki.fi> Reviewed-by: Tender Wang <tndrwang@gmail.com> Reviewed-by: Gurjeet Singh <gurjeet@singh.im> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/CAPmGK17%3DPHSDZ%2B0G6jcj12buyyE1bQQc3sbp1Wxri7tODT-SDw%40mail.gmail.com Backpatch-through: 15
2025-04-23Avoid possibly-theoretical OOM crash hazard in hash_create().Tom Lane
One place in hash_create() used DynaHashAlloc() as a convenient shorthand for MemoryContextAlloc(). That was fine when it was written, but it stopped being fine when 9c911ec06 changed DynaHashAlloc() to use MCXT_ALLOC_NO_OOM (mea culpa). Change the code to call plain MemoryContextAlloc() as intended. I think that this bug may be unreachable in practice, since we now always create AllocSets with some space already allocated, so that an OOM failure here for a non-shared hash table should be impossible (with a hash table name of reasonable length anyway). And there aren't enough shared hash tables to make a crash for one of those probable. Nonetheless it's clearly not operating as designed, so back-patch to v16 where 9c911ec06 came in. Reported-by: Maksim Korotkov <m.korotkov@postgrespro.ru> Author: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/219bdccd460510efaccf90b57e5e5ef2@postgrespro.ru Backpatch-through: 16
2025-04-23Remove assertion based on pending_since in pgstat_report_stat()Michael Paquier
This assertion, based on pending_since (timestamp used to prevent stats reports to be too frequent or should a partial flush happen), is reached when it is found that no data can be flushed but a previous call of pgstat_report_stat() determined that some stats data has been found as in need of a flush. So pending_since is set when some stats data is pending (in non-force mode) or if report attempts are too frequent, and reset to 0 once all stats have been flushed. Since 5cbbe70a9cc6, WAL senders have begun to report their stats on a periodic basis for IO stats in v16~ and backend stats on HEAD, creating some friction with the concurrent pgstat_report_stat() calls that can happen in the context of a WAL sender (shutdown callback doing a final report or backend-related code paths). This problem is the cause of spurious failures in the TAP tests. In theory, this assertion can be also reached in v15, even if that's very unlikely. For example, a process, say a background worker, could do periodic and direct stats flushes with concurrent calls of pgstat_report_stat() that could cause conflicting values of pending_since. This can be done with WAL or SLRU stats flushes using pgstat_flush_wal() or pgstat_slru_flush(). HEAD makes this situation easier to happen with custom cumulative stats. This commit removes the assertion altogether, per discussion, as it is more useful to keep the state of things as they are for the WAL sender. The assertion could use a special state based on for example am_walsender, but I doubt that this would be meaningful in the long run based on the other arguments raised while discussing this issue. Reported-by: Tom Lane <tgl@sss.pgh.pa.us> Reported-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/1489124.1744685908@sss.pgh.pa.us Discussion: https://postgr.es/m/dwrkeszz6czvtkxzr5mqlciy652zau5qqnm3cp5f3p2po74ppk@omg4g3cc6dgq Backpatch-through: 15
2025-04-22Rename injection point for invalidation messages at end of transactionMichael Paquier
This injection point was named "AtEOXact_Inval-with-transInvalInfo", not respecting the implied naming convention that injection points should use lower-case characters, with terms separated by dashes. All the other points defined in the tree follow this style, so let's be more consistent. Author: Hayato Kuroda <kuroda.hayato@fujitsu.com> Reviewed-by: Aleksander Alekseev <aleksander@timescale.com> Discussion: https://postgr.es/m/OSCPR01MB14966E14C1378DEE51FB7B7C5F5B32@OSCPR01MB14966.jpnprd01.prod.outlook.com Backpatch-through: 17
2025-04-02Remove unnecessary type violation in tsvectorrecv().Tom Lane
compareentry() is declared to work on WordEntryIN structs, but tsvectorrecv() is using it in two places to work on WordEntry structs. This is almost okay, since WordEntry is the first field of WordEntryIN. But on machines with 8-byte pointers, WordEntryIN will have a larger alignment spec than WordEntry, and it's at least theoretically possible that the compiler could generate code that depends on the larger alignment. Given the lack of field reports, this may be just a hypothetical bug that upsets nothing except sanitizer tools. Or it may be real on certain hardware but nobody's tried to use tsvectorrecv() on such hardware. In any case we should fix it, and the fix is trivial: just change compareentry() so that it works on WordEntry without any mention of WordEntryIN. We can also get rid of the quite-useless intermediate function WordEntryCMP. Bug: #18875 Reported-by: Alexander Lakhin <exclusion@gmail.com> Author: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/18875-07a29c49c825a608@postgresql.org Backpatch-through: 13
2025-03-13Fix ARRAY_SUBLINK and ARRAY[] for int2vector and oidvector input.Tom Lane
If the given input_type yields valid results from both get_element_type and get_array_type, initArrayResultAny believed the former and treated the input as an array type. However this is inconsistent with what get_promoted_array_type does, leading to situations where the output of an ARRAY() subquery is labeled with the wrong type: it's labeled as oidvector[] but is really a 2-D array of OID. That at least results in strange output, and can result in crashes if further processing such as unnest() is applied. AFAIK this is only possible with the int2vector and oidvector types, which are special-cased to be treated mostly as true arrays even though they aren't quite. Fix by switching the logic to match get_promoted_array_type by testing get_array_type not get_element_type, and remove an Assert thereby made pointless. (We need not introduce a symmetrical check for get_element_type in the other if-branch, because initArrayResultArr will check it.) This restores the behavior that existed before bac27394a introduced initArrayResultAny: the output really is int2vector[] or oidvector[]. Comparable confusion exists when an input of an ARRAY[] construct is int2vector or oidvector: transformArrayExpr decides it's dealing with a multidimensional array constructor, and we end up with something that's a multidimensional OID array but is alleged to be of type oidvector. I have not found a crashing case here, but it's easy to demonstrate totally-wrong results. Adjust that code so that what you get is an oidvector[] instead, for consistency with ARRAY() subqueries. (This change also makes these types work like domains-over-arrays in this context, which seems correct.) Bug: #18840 Reported-by: yang lei <ylshiyu@126.com> Author: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/18840-fbc9505f066e50d6@postgresql.org Backpatch-through: 13
2025-03-13Fix copy-paste error in datum_to_jsonb_internal()Amit Langote
Commit 3c152a27b06 mistakenly repeated JSONTYPE_JSON in a condition, omitting JSONTYPE_CAST. As a result, datum_to_jsonb_internal() failed to reject inputs that were casts (e.g., from an enum to json as in the example below) when used as keys in JSON constructors. This led to a crash in cases like: SELECT JSON_OBJECT('happy'::mood: '123'::jsonb); where 'happy'::mood is implicitly cast to json. The missing check meant such casted values weren’t properly rejected as invalid (non-scalar) JSON keys. Reported-by: Maciek Sakrejda <maciek@pganalyze.com> Reviewed-by: Tender Wang <tndrwang@gmail.com> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Maciek Sakrejda <maciek@pganalyze.com> Discussion: https://postgr.es/m/CADXhmgTJtJZK9A3Na_ry+Xrq-ghjcejBRhcRMzWZvbd__QdgJA@mail.gmail.com Backpatch-through: 17
2025-02-21Add missing deparsing of [NO] IDENT to XMLSERIALIZE()Michael Paquier
NO INDENT is the default, and is added if no explicit indentation flag was provided with XMLSERIALIZE(). Oversight in 483bdb2afec9. Author: Jim Jones <jim.jones@uni-muenster.de> Discussion: https://postgr.es/m/bebd457e-5b43-46b3-8fc6-f6a6509483ba@uni-muenster.de Backpatch-through: 16
2025-02-02Mention jsonlog in description of logging_collector in GUC tableMichael Paquier
logging_collector was only mentioning stderr and csvlog, and forgot about jsonlog. Oversight in dc686681e079, that has added support for jsonlog in log_destination. While on it, the description in the GUC table is tweaked to be more consistent with the documentation and postgresql.conf.sample. Author: Umar Hayat Reviewed-by: Ashutosh Bapat, Tom Lane Discussion: https://postgr.es/m/CAD68Dp1K_vBYqBEukHw=1jF7e76t8aszGZTFL2ugi=H7r=a7MA@mail.gmail.com Backpatch-through: 13
2025-01-25At update of non-LP_NORMAL TID, fail instead of corrupting page header.Noah Misch
The right mix of DDL and VACUUM could corrupt a catalog page header such that PageIsVerified() durably fails, requiring a restore from backup. This affects only catalogs that both have a syscache and have DDL code that uses syscache tuples to construct updates. One of the test permutations shows a variant not yet fixed. This makes !TransactionIdIsValid(TM_FailureData.xmax) possible with TM_Deleted. I think core and PGXN are indifferent to that. Per bug #17821 from Alexander Lakhin. Back-patch to v13 (all supported versions). The test case is v17+, since it uses INJECTION_POINT. Discussion: https://postgr.es/m/17821-dd8c334263399284@postgresql.org
2025-01-25Merge copies of converting an XID to a FullTransactionId.Noah Misch
Assume twophase.c is the performance-sensitive caller, and preserve its choice of unlikely() branch hint. Add some retrospective rationale for that choice. Back-patch to v17, for the next commit to use it. Reviewed (in earlier versions) by Michael Paquier. Discussion: https://postgr.es/m/17821-dd8c334263399284@postgresql.org Discussion: https://postgr.es/m/20250116010051.f3.nmisch@google.com
2025-01-21Reword recent error messages: "should" -> "must"Álvaro Herrera
Most were introduced in the 17 timeframe. The ones in wparser_def.c are very old. I also changed "JSON path expression for column \"%s\" should return single item without wrapper" to "JSON path expression for column \"%s\" must return single item when no wrapper is requested" to avoid ambiguity. Backpatch to 17. Crickets: https://postgr.es/m/202501131819.26ors7oouafu@alvherre.pgsql
2025-01-14Fix catcache invalidation of a list entry that's being builtHeikki Linnakangas
If a new catalog tuple is inserted that belongs to a catcache list entry, and cache invalidation happens while the list entry is being built, the list entry might miss the newly inserted tuple. To fix, change the way we detect concurrent invalidations while a catcache entry is being built. Keep a stack of entries that are being built, and apply cache invalidation to those entries in addition to the real catcache entries. This is similar to the in-progress list in relcache.c. Back-patch to all supported versions. Reviewed-by: Noah Misch Discussion: https://www.postgresql.org/message-id/2234dc98-06fe-42ed-b5db-ac17384dc880@iki.fi
2025-01-12Fix HBA option countDaniel Gustafsson
Commit 27a1f8d108 missed updating the max HBA option count to account for the new option added. Fix by bumping the counter and adjust the relevant comment to match. Backpatch down to all supported branches like the erroneous commit. Reported-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/286764.1736697356@sss.pgh.pa.us Backpatch-through: v13
2025-01-12Fix JsonExpr deparsing to quote variable names in the PASSING clause.Dean Rasheed
When deparsing a JsonExpr, variable names in the PASSING clause were not quoted. However, since they are parsed as ColLabel tokens, some variable names require double quotes to ensure that they are properly interpreted. Fix by using quote_identifier() in the deparsing code. This oversight was limited to the SQL/JSON query functions JSON_EXISTS(), JSON_QUERY(), and JSON_VALUE(). Back-patch to v17, where these functions were added. Dean Rasheed, reviewed by Tom Lane. Discussion: https://postgr.es/m/CAEZATCXTpAS%3DncfLNTZ7YS6O5puHeLg_SUYAit%2Bcs7wsrd9Msg%40mail.gmail.com
2025-01-12Fix XMLTABLE() deparsing to quote namespace names if necessary.Dean Rasheed
When deparsing an XMLTABLE() expression, XML namespace names were not quoted. However, since they are parsed as ColLabel tokens, some names require double quotes to ensure that they are properly interpreted. Fix by using quote_identifier() in the deparsing code. Back-patch to all supported versions. Dean Rasheed, reviewed by Tom Lane. Discussion: https://postgr.es/m/CAEZATCXTpAS%3DncfLNTZ7YS6O5puHeLg_SUYAit%2Bcs7wsrd9Msg%40mail.gmail.com
2025-01-10Fix missing ldapscheme option in pg_hba_file_rules()Daniel Gustafsson
The ldapscheme option was missed when inspecing the HbaLine for assembling rows for the pg_hba_file_rules function. Backpatch to all supported versions. Author: Laurenz Albe <laurenz.albe@cybertec.at> Reported-by: Laurenz Albe <laurenz.albe@cybertec.at> Reviewed-by: Daniel Gustafsson <daniel@yesql.se> Bug: 18769 Discussion: https://postgr.es/m/18769-dd8610cbc0405172@postgresql.org Backpatch-through: v13
2025-01-02Ignore nullingrels when looking up statisticsRichard Guo
When looking up statistical data about an expression, we do not need to concern ourselves with the outer joins that could null the Vars/PHVs contained in the expression. Accounting for nullingrels in the expression could cause estimate_num_groups to count the same Var multiple times if it's marked with different nullingrels. This is incorrect, and could lead to "ERROR: corrupt MVNDistinct entry" when searching for multivariate n-distinct. Furthermore, the nullingrels could prevent us from matching an expression to expressional index columns or to the expressions in extended statistics, leading to inaccurate estimates. To fix, strip out all the nullingrels from the expression before we look up statistical data about it. There is one ensuing plan change in the regression tests, but it looks reasonable and does not compromise its original purpose. This patch could result in plan changes, but it fixes an actual bug, so back-patch to v16 where the outer-join-aware-Var infrastructure was introduced. Author: Richard Guo Discussion: https://postgr.es/m/CAMbWs4-2Z4k+nFTiZe0Qbu5n8juUWenDAtMzi98bAZQtwHx0-w@mail.gmail.com
2024-12-28Exclude parallel workers from connection privilege/limit checks.Tom Lane
Cause parallel workers to not check datallowconn, rolcanlogin, and ACL_CONNECT privileges. The leader already checked these things (except for rolcanlogin which might have been checked for a different role). Re-checking can accomplish little except to induce unexpected failures in applications that might not even be aware that their query has been parallelized. We already had the principle that parallel workers rely on their leader to pass a valid set of authorization information, so this change just extends that a bit further. Also, modify the ReservedConnections, datconnlimit and rolconnlimit logic so that these limits are only enforced against regular backends, and only regular backends are counted while checking if the limits were already reached. Previously, background processes that had an assigned database or role were subject to these limits (with rather random exclusions for autovac workers and walsenders), and the set of existing processes that counted against each limit was quite haphazard as well. The point of these limits, AFAICS, is to ensure the availability of PGPROC slots for regular backends. Since all other types of processes have their own separate pools of PGPROC slots, it makes no sense either to enforce these limits against them or to count them while enforcing the limit. While edge-case failures of these sorts have been possible for a long time, the problem got a good deal worse with commit 5a2fed911 (CVE-2024-10978), which caused parallel workers to make some of these checks using the leader's current role where before we had used its AuthenticatedUserId, thus allowing parallel queries to fail after SET ROLE. The previous behavior was fairly accidental and I have no desire to return to it. This patch includes reverting 73c9f91a1, which was an emergency hack to suppress these same checks in some cases. It wasn't complete, as shown by a recent bug report from Laurenz Albe. We can also revert fd4d93d26 and 492217301, which hacked around the same problems in one regression test. In passing, remove the special case for autovac workers in CheckMyDatabase; it seems cleaner to have AutoVacWorkerMain pass the INIT_PG_OVERRIDE_ALLOW_CONNS flag, now that that does what's needed. Like 5a2fed911, back-patch to supported branches (which sadly no longer includes v12). Discussion: https://postgr.es/m/1808397.1735156190@sss.pgh.pa.us
2024-12-28Reserve a PGPROC slot and semaphore for the slotsync worker process.Tom Lane
The need for this was missed in commit 93db6cbda, with the result being that if we launch a slotsync worker it would consume one of the PGPROCs in the max_connections pool. That could lead to inability to launch the worker, or to subsequent failures of connection requests that should have succeeded according to the configured settings. Rather than create some one-off infrastructure to support this, let's group the slotsync worker with the existing autovac launcher in a new category of "special worker" processes. These are kind of like auxiliary processes, but they cannot use that infrastructure because they need to be able to run transactions. For the moment, make these processes share the PGPROC freelist used for autovac workers (which previously supplied the autovac launcher too). This is partly to avoid an ABI change in v17, and partly because it seems silly to have a freelist with at most two members. This might be worth revisiting if we grow enough workers in this category. Tom Lane and Hou Zhijie. Back-patch to v17. Discussion: https://postgr.es/m/1808397.1735156190@sss.pgh.pa.us
2024-12-21Update TransactionXmin when MyProc->xmin is updatedHeikki Linnakangas
GetSnapshotData() set TransactionXmin = MyProc->xmin, but when SnapshotResetXmin() advanced MyProc->xmin, it did not advance TransactionXmin correspondingly. That meant that TransactionXmin could be older than MyProc->xmin, and XIDs between than TransactionXmin and the real MyProc->xmin could be vacuumed away. One known consequence is in pg_subtrans lookups: we might try to look up the status of an XID that was already truncated away. Back-patch to all supported versions. Reviewed-by: Andres Freund Discussion: https://www.postgresql.org/message-id/d27a046d-a1e4-47d1-a95c-fbabe41debb4@iki.fi
2024-12-09Improve comment about dropped entries in pgstat.cMichael Paquier
pgstat_write_statsfile() discards any entries marked as dropped from being written to the stats file at shutdown, and also included an assertion based on the same condition. The intention of the assertion is to track that no pgstats entries should be left around as terminating backends should drop any entries they still hold references on before the stats file is written by the checkpointer, and it not worth taking down the server in this case if there is a bug making that possible. Let's improve the comment of this area to document clearly what's intended. Based on a discussion with Bertrand Drouvot and Anton A. Melnikov. Author: Bertrand Drouvot Discussion: https://postgr.es/m/a13e8cdf-b97a-4ecb-8f42-aaa367974e29@postgrespro.ru Backpatch-through: 15
2024-12-09Fix invalidation of local pgstats references for entry reinitializationMichael Paquier
818119afccd3 has introduced the "generation" concept in pgstats entries, incremented a counter when a pgstats entry is reinitialized, but it did not count on the fact that backends still holding local references to such entries need to be refreshed if the cache age is outdated. The previous logic only updated local references when an entry was dropped, but it needs also to consider entries that are reinitialized. This matters for replication slot stats (as well as custom pgstats kinds in 18~), where concurrent drops and creates of a slot could cause incorrect stats to be locally referenced. This would lead to an assertion failure at shutdown when writing out the stats file, as the backend holding an outdated local reference would not be able to drop during its shutdown sequence the stats entry that should be dropped, as the last process holding a reference to the stats entry. The checkpointer was then complaining about such an entry late in the shutdown sequence, after the shutdown checkpoint is finished with the control file updated, causing the stats file to not be generated. In non-assert builds, the entry would just be skipped with the stats file written. Note that only logical replication slots use statistics. A test case based on TAP is added to test_decoding, where a persistent connection peeking at a slot's data is kept with concurrent drops and creates of the same slot. This is based on the isolation test case that Anton has sent. As it requires a node shutdown with a check to make sure that the stats file is written with this specific sequence of events, TAP is used instead. Reported-by: Anton A. Melnikov Reviewed-by: Bertrand Drouvot Discussion: https://postgr.es/m/56bf8ff9-dd8c-47b2-872a-748ede82af99@postgrespro.ru Backpatch-through: 15
2024-12-07Fix is_digit labeling of to_timestamp's FFn format codes.Tom Lane
These format codes produce or consume strings of digits, so they should be labeled with is_digit = true, but they were not. This has effect in only one place, where is_next_separator() is checked to see if the preceding format code should slurp up all the available digits. Thus, with a format such as '...SSFF3' with remaining input '12345', the 'SS' code would consume all five digits (and then complain about seconds being out of range) when it should eat only two digits. Per report from Nick Davies. This bug goes back to d589f9446 where the FFn codes were introduced, so back-patch to v13. Discussion: https://postgr.es/m/AM8PR08MB6356AC979252CFEA78B56678B6312@AM8PR08MB6356.eurprd08.prod.outlook.com
2024-11-27Fix pg_get_constraintdef for NOT NULL constraints on domainsÁlvaro Herrera
We added pg_constraint rows for all not-null constraints, first for tables and later for domains; but while the ones for tables were reverted, the ones for domains were not. However, we did accidentally revert ruleutils.c support for the ones on domains in 6f8bb7c1e961, which breaks running pg_get_constraintdef() on them. Put that back. This is only needed in branch 17, because we've reinstated this code in branch master with commit 14e87ffa5c54. Add some new tests in both branches. I couldn't find anything else that needs de-reverting. Reported-by: Erki Eessaar <erki.eessaar@taltech.ee> Reviewed-by: Magnus Hagander <magnus@hagander.net> Discussion: https://postgr.es/m/AS8PR01MB75110350415AAB8BBABBA1ECFE222@AS8PR01MB7511.eurprd01.prod.exchangelabs.com
2024-11-26Clean up newlines following left parenthesesÁlvaro Herrera
Most came in during the 17 cycle, so backpatch there. Some (particularly reorderbuffer.h) are very old, but backpatching doesn't seem useful. Like commits c9d297751959, c4f113e8fef9.
2024-11-25Avoid "you don't own a lock of type ExclusiveLock" in GRANT TABLESPACE.Noah Misch
This WARNING appeared because SearchSysCacheLocked1() read cc_relisshared before catcache initialization, when the field is false unconditionally. On the basis of reading false there, it constructed a locktag as though pg_tablespace weren't relisshared. Only shared catalogs could be affected, and only GRANT TABLESPACE was affected in practice. SearchSysCacheLocked1() callers use one other shared-relation syscache, DATABASEOID. DATABASEOID is initialized by the end of CheckMyDatabase(), making the problem unreachable for pg_database. Back-patch to v13 (all supported versions). This has no known impact before v16, where ExecGrant_common() first appeared. Earlier branches avoid trouble by having a separate ExecGrant_Tablespace() that doesn't use LOCKTAG_TUPLE. However, leaving this unfixed in v15 could ensnare a future back-patch of a SearchSysCacheLocked1() call. Reported by Aya Iwata. Discussion: https://postgr.es/m/OS7PR01MB11964507B5548245A7EE54E70EA212@OS7PR01MB11964.jpnprd01.prod.outlook.com
2024-11-20Avoid assertion failure if a setop leaf query contains setops.Tom Lane
Ordinarily transformSetOperationTree will collect all UNION/ INTERSECT/EXCEPT steps into the setOperations tree of the topmost Query, so that leaf queries do not contain any setOperations. However, it cannot thus flatten a subquery that also contains WITH, ORDER BY, FOR UPDATE, or LIMIT. I (tgl) forgot that in commit 07b4c48b6 and wrote an assertion in rule deparsing that a leaf's setOperations would always be empty. If it were nonempty then we would want to parenthesize the subquery to ensure that the output represents the setop nesting correctly (e.g. UNION below INTERSECT had better get parenthesized). So rather than just removing the faulty Assert, let's change it into an additional case to check to decide whether to add parens. We don't expect that the additional case will ever fire, but it's cheap insurance. Man Zeng and Tom Lane Discussion: https://postgr.es/m/tencent_7ABF9B1F23B0C77606FC5FE3@qq.com
2024-11-15Fix per-session activation of ALTER {ROLE|DATABASE} SET role.Noah Misch
After commit 5a2fed911a85ed6d8a015a6bafe3a0d9a69334ae, the catalog state resulting from these commands ceased to affect sessions. Restore the longstanding behavior, which is like beginning the session with a SET ROLE command. If cherry-picking the CVE-2024-10978 fixes, default to including this, too. (This fixes an unintended side effect of fixing CVE-2024-10978.) Back-patch to v12, like that commit. The release team decided to include v12, despite the original intent to halt v12 commits earlier this week. Tom Lane and Noah Misch. Reported by Etienne LAFARGE. Discussion: https://postgr.es/m/CADOZwSb0UsEr4_UTFXC5k7=fyyK8uKXekucd+-uuGjJsGBfxgw@mail.gmail.com
2024-11-15Fix race conditions with drop of reused pgstats entriesMichael Paquier
This fixes a set of race conditions with cumulative statistics where a shared stats entry could be dropped while it should still be valid in the event when it is reused: an entry may refer to a different object but requires the same hash key. This can happen with various stats kinds, like: - Replication slots that compute internally an index number, for different slot names. - Stats kinds that use an OID in the object key, where a wraparound causes the same key to be used if an OID is used for the same object. - As of PostgreSQL 18, custom pgstats kinds could also be an issue, depending on their implementation. This issue is fixed by introducing a counter called "generation" in the shared entries via PgStatShared_HashEntry, initialized at 0 when an entry is created and incremented when the same entry is reused, to avoid concurrent issues on drop because of other backends still holding a reference to it. This "generation" is copied to the local copy that a backend holds when looking at an object, then cross-checked with the shared entry to make sure that the entry is not dropped even if its "refcount" justifies that if it has been reused. This problem could show up when a backend shuts down and needs to discard any entries it still holds, causing statistics to be removed when they should not, or even an assertion failure. Another report involved a failure in a standby after an OID wraparound, where the startup process would FATAL on a "can only drop stats once", stopping recovery abruptly. The buildfarm has been sporadically complaining about the problem, as well, but the window is hard to reach with the in-core tests. Note that the issue can be reproduced easily by adding a sleep before dshash_find() in pgstat_release_entry_ref() to enlarge the problematic window while repeating test_decoding's isolation test oldest_xmin a couple of times, for example, as pointed out by Alexander Lakhin. Reported-by: Alexander Lakhin, Peter Smith Author: Kyotaro Horiguchi, Michael Paquier Reviewed-by: Bertrand Drouvot Discussion: https://postgr.es/m/CAA4eK1KxuMVyAryz_Vk5yq3ejgKYcL6F45Hj9ZnMNBS-g+PuZg@mail.gmail.com Discussion: https://postgr.es/m/17947-b9554521ad963c9c@postgresql.org Backpatch-through: 15
2024-11-13Fix comment in injection_point.cMichael Paquier
InjectionPointEntry->name was described as a hash key, which was fine when introduced in d86d20f0ba79, but it is not now. Oversight in 86db52a5062a, that has changed the way injection points are stored in shared memory from a hash table to an array. Backpatch-through: 17
2024-11-11Parallel workers use AuthenticatedUserId for connection privilege checks.Tom Lane
Commit 5a2fed911 had an unexpected side-effect: the parallel worker launched for the new test case would fail if it couldn't use a superuser-reserved connection slot. The reason that test failed while all our pre-existing ones worked is that the connection privilege tests in InitPostgres had been based on the superuserness of the leader's AuthenticatedUserId, but after the rearrangements of 5a2fed911 we were testing the superuserness of CurrentUserId, which the new test case deliberately made to be a non-superuser. This all seems very accidental and probably not the behavior we really want, but a security patch is no time to be redesigning things. Pending some discussion about desirable semantics, hack it so that InitPostgres continues to pay attention to the superuserness of AuthenticatedUserId when starting a parallel worker. Nathan Bossart and Tom Lane, per buildfarm member sawshark. Security: CVE-2024-10978
2024-11-11Fix improper interactions between session_authorization and role.Tom Lane
The SQL spec mandates that SET SESSION AUTHORIZATION implies SET ROLE NONE. We tried to implement that within the lowest-level functions that manipulate these settings, but that was a bad idea. In particular, guc.c assumes that it doesn't matter in what order it applies GUC variable updates, but that was not the case for these two variables. This problem, compounded by some hackish attempts to work around it, led to some security-grade issues: * Rolling back a transaction that had done SET SESSION AUTHORIZATION would revert to SET ROLE NONE, even if that had not been the previous state, so that the effective user ID might now be different from what it had been. * The same for SET SESSION AUTHORIZATION in a function SET clause. * If a parallel worker inspected current_setting('role'), it saw "none" even when it should see something else. Also, although the parallel worker startup code intended to cope with the current role's pg_authid row having disappeared, its implementation of that was incomplete so it would still fail. Fix by fully separating the miscinit.c functions that assign session_authorization from those that assign role. To implement the spec's requirement, teach set_config_option itself to perform "SET ROLE NONE" when it sets session_authorization. (This is undoubtedly ugly, but the alternatives seem worse. In particular, there's no way to do it within assign_session_authorization without incompatible changes in the API for GUC assign hooks.) Also, improve ParallelWorkerMain to directly set all the relevant user-ID variables instead of relying on some of them to get set indirectly. That allows us to survive not finding the pg_authid row during worker startup. In v16 and earlier, this includes back-patching 9987a7bf3 which fixed a violation of GUC coding rules: SetSessionAuthorization is not an appropriate place to be throwing errors from. Security: CVE-2024-10978
2024-11-06Fix lc_collate_is_c() when LC_COLLATE != LC_CTYPE.Jeff Davis
An unfortunate typo in commit 2d819a08a1 can cause wrong results when the default collation provider is libc, LC_CTYPE=C, and LC_COLLATE is a real locale. Users with this combination of settings must REINDEX all affected indexes. The same typo can also cause performance degradation when LC_COLLATE=C and LC_CTYPE is a real locale. Problem does not exist in master (due to refactoring), so fix only in version 17. Reported-by: Drew Callahan Discussion: https://postgr.es/m/d5081a7f4f6d425c28dd69d1e09b2e78f149e726.camel@j-davis.com
2024-11-05Clear padding of PgStat_HashKey when handling pgstats entriesMichael Paquier
PgStat_HashKey is currently initialized in a way that could result in random data if the structure has any padding bytes. The structure has no padding bytes currently, fortunately, but it could become a problem should the structure change at some point in the future. The code is changed to use some memset(0) so as any padding would be handled properly, as it would be surprising to see random failures in the pgstats entry lookups. PgStat_HashKey is a structure internal to pgstats, and an ABI change could be possible in the scope of a bug fix, so backpatch down to 15 where this has been introduced. Author: Bertrand Drouvot Reviewed-by: Jelte Fennema-Nio, Michael Paquier Discussion: https://postgr.es/m/Zyb7RW1y9dVfO0UH@ip-10-97-1-34.eu-west-3.compute.internal Backpatch-through: 15
2024-11-02Revert "For inplace update, send nontransactional invalidations."Noah Misch
This reverts commit 95c5acb3fc261067ab65ddc0b2dca8e162f09442 (v17) and counterparts in each other non-master branch. If released, that commit would have caused a worst-in-years minor release regression, via undetected LWLock self-deadlock. This commit and its self-deadlock fix warrant more bake time in the master branch. Reported by Alexander Lakhin. Discussion: https://postgr.es/m/10ec0bc3-5933-1189-6bb8-5dec4114558e@gmail.com
2024-10-25For inplace update, send nontransactional invalidations.Noah Misch
The inplace update survives ROLLBACK. The inval didn't, so another backend's DDL could then update the row without incorporating the inplace update. In the test this fixes, a mix of CREATE INDEX and ALTER TABLE resulted in a table with an index, yet relhasindex=f. That is a source of index corruption. Back-patch to v12 (all supported versions). The back branch versions don't change WAL, because those branches just added end-of-recovery SIResetAll(). All branches change the ABI of extern function PrepareToInvalidateCacheTuple(). No PGXN extension calls that, and there's no apparent use case in extensions. Reviewed by Nitin Motiani and (in earlier versions) Andres Freund. Discussion: https://postgr.es/m/20240523000548.58.nmisch@google.com
2024-10-11Fix missed case for builtin collation provider.Jeff Davis
A missed check for the builtin collation provider could result in falling through to call isalpha(). This does not appear to have practical consequences because it only happens for characters in the ASCII range. Regardless, the builtin provider should not be calling libc functions, so backpatch. Discussion: https://postgr.es/m/1bd5a0a5192f82c22ee7527e825b18ab0028b2c7.camel@j-davis.com Backpatch-through: 17
2024-10-09Avoid crash in estimate_array_length with null root pointer.Tom Lane
Commit 9391f7152 added a "PlannerInfo *root" parameter to estimate_array_length, but failed to consider the possibility that NULL would be passed for that, leading to a null pointer dereference. We could rectify the particular case shown in the bug report by fixing simplify_function/inline_function to pass through the root pointer. However, as long as eval_const_expressions is documented to accept NULL for root, similar hazards would remain. For now, let's just do the narrow fix of hardening estimate_array_length to not crash. Its behavior with NULL root will be the same as it was before 9391f7152, so this is not too awful. Per report from Fredrik Widlert (via Paul Ramsey). Back-patch to v17 where 9391f7152 came in. Discussion: https://postgr.es/m/518339E7-173E-45EC-A0FF-9A4A62AA4F40@cleverelephant.ca
2024-10-07Fix Y2038 issues with MyStartTime.Nathan Bossart
Several places treat MyStartTime as a "long", which is only 32 bits wide on some platforms. In reality, MyStartTime is a pg_time_t, i.e., a signed 64-bit integer. This will lead to interesting bugs on the aforementioned systems in 2038 when signed 32-bit integers are no longer sufficient to store Unix time (e.g., "pg_ctl start" hanging). To fix, ensure that MyStartTime is handled as a 64-bit value everywhere. (Of course, users will need to ensure that time_t is 64 bits wide on their system, too.) Co-authored-by: Max Johnson Discussion: https://postgr.es/m/CO1PR07MB905262E8AC270FAAACED66008D682%40CO1PR07MB9052.namprd07.prod.outlook.com Backpatch-through: 12
2024-10-06Ignore not-yet-defined Portals in pg_cursors view.Tom Lane
pg_cursor() supposed that any Portal it finds in the hash table must have sourceText set up, but there's an edge case where that is not so. A newly-created Portal has sourceText = NULL, and that doesn't change until PortalDefineQuery is called. In SPI_cursor_open_internal, we perform GetCachedPlan between CreatePortal and PortalDefineQuery, and it's possible for user-defined code to execute during that planning and cause a fetch from the pg_cursors view, resulting in a null-pointer-dereference crash. (It looks like the same could happen in exec_bind_message, but I've not tried to provoke a failure there.) I considered trying to fix this by setting sourceText sooner, but there may be instances of this same calling pattern in extensions, and we couldn't be sure they'd get the memo promptly. It seems better to redefine pg_cursor as not showing Portals that have not yet had PortalDefineQuery called on them, which we can do by just skipping them if sourceText is still NULL. (Before a1c692358, pg_cursor would instead return a row with NULL in the statement column. We could revert to that behavior but it doesn't really seem like a better definition, especially since our documentation doesn't suggest that the column could be NULL.) Per report from PetSerAl. Back-patch to all supported branches. Discussion: https://postgr.es/m/CAKygsHTBXLXjwV43kpZa+Cs+XTiaeeJiZdL4cPBm9f4MTdw7wg@mail.gmail.com
2024-10-05Reject non-ASCII locale names.Thomas Munro
Commit bf03cfd1 started scanning all available BCP 47 locale names on Windows. This caused an abort/crash in the Windows runtime library if the default locale name contained non-ASCII characters, because of our use of the setlocale() save/restore pattern with "char" strings. After switching to another locale with a different encoding, the saved name could no longer be understood, and setlocale() would abort. "Turkish_Türkiye.1254" is the example from recent reports, but there are other examples of countries and languages with non-ASCII characters in their names, and they appear in Windows' (old style) locale names. To defend against this: 1. In initdb, reject non-ASCII locale names given explicity on the command line, or returned by the operating system environment with setlocale(..., ""), or "canonicalized" by the operating system when we set it. 2. In initdb only, perform the save-and-restore with Windows' non-standard wchar_t variant of setlocale(), so that it is not subject to round trip failures stemming from char string encoding confusion. 3. In the backend, we don't have to worry about the save-and-restore problem because we have already vetted the defaults, so we just have to make sure that CREATE DATABASE also rejects non-ASCII names in any new databases. SET lc_XXX doesn't suffer from the problem, but the ban applies to it too because it uses check_locale(). CREATE COLLATION doesn't suffer from the problem either, but it doesn't use check_locale() so it is not included in the new ban for now, to minimize the change. Anyone who encounters the new error message should either create a new duplicated locale with an ASCII-only name using Windows Locale Builder, or consider using BCP 47 names like "tr-TR". Users already couldn't initialize a cluster with "Turkish_Türkiye.1254" on PostgreSQL 16+, but the new failure mode is an error message that explains why, instead of a crash. Back-patch to 16, where bf03cfd1 landed. Older versions are affected in theory too, but only 16 and later are causing crash reports. Reviewed-by: Andrew Dunstan <andrew@dunslane.net> (the idea, not the patch) Reported-by: Haifang Wang (Centific Technologies Inc) <v-haiwang@microsoft.com> Discussion: https://postgr.es/m/PH8PR21MB3902F334A3174C54058F792CE5182%40PH8PR21MB3902.namprd21.prod.outlook.com
2024-09-24For inplace update durability, make heap_update() callers wait.Noah Misch
The previous commit fixed some ways of losing an inplace update. It remained possible to lose one when a backend working toward a heap_update() copied a tuple into memory just before inplace update of that tuple. In catalogs eligible for inplace update, use LOCKTAG_TUPLE to govern admission to the steps of copying an old tuple, modifying it, and issuing heap_update(). This includes MERGE commands. To avoid changing most of the pg_class DDL, don't require LOCKTAG_TUPLE when holding a relation lock sufficient to exclude inplace updaters. Back-patch to v12 (all supported versions). In v13 and v12, "UPDATE pg_class" or "UPDATE pg_database" can still lose an inplace update. The v14+ UPDATE fix needs commit 86dc90056dfdbd9d1b891718d2e5614e3e432f35, and it wasn't worth reimplementing that fix without such infrastructure. Reviewed by Nitin Motiani and (in earlier versions) Heikki Linnakangas. Discussion: https://postgr.es/m/20231027214946.79.nmisch@google.com
2024-09-15Replace usages of xmlXPathCompile() with xmlXPathCtxtCompile().Tom Lane
In existing releases of libxml2, xmlXPathCompile can be driven to stack overflow because it fails to protect itself against too-deeply-nested input. While there is an upstream fix as of yesterday, it will take years for that to propagate into all shipping versions. In the meantime, we can protect our own usages basically for free by calling xmlXPathCtxtCompile instead. (The actual bug is that libxml2 keeps its nesting counter in the xmlXPathContext, and its parsing code was willing to just skip counting nesting levels if it didn't have a context. So if we supply a context, all is well. It seems odd actually that it works at all to not supply a context, because this means that XPath parsing does not have access to XML namespace info. Apparently libxml2 never checks namespaces until runtime? Anyway, this seems like good future-proofing even if its only immediate effect is to dodge a bug.) Sadly, this hack only offers protection with libxml2 2.9.11 and newer. Before that there are multiple similar problems, so if you are processing untrusted XML it behooves you to get a newer version. But we have some pretty old libxml2 in the buildfarm, so it seems impractical to add a regression test to verify this fix. Per bug #18617 from Jingzhou Fu. Back-patch to all supported versions. Discussion: https://postgr.es/m/18617-1cee4d2ed1f4e7ae@postgresql.org Discussion: https://gitlab.gnome.org/GNOME/libxml2/-/issues/799