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2019-07-18Fix error in commit e6feef57.Jeff Davis
I was careless passing a datum directly to DATE_NOT_FINITE without calling DatumGetDateADT() first. Backpatch-through: 9.4
2019-07-18Fix daterange canonicalization for +/- infinity.Jeff Davis
The values 'infinity' and '-infinity' are a part of the DATE type itself, so a bound of the date 'infinity' is not the same as an unbounded/infinite range. However, it is still wrong to try to canonicalize such values, because adding or subtracting one has no effect. Fix by treating 'infinity' and '-infinity' the same as unbounded ranges for the purposes of canonicalization (but not other purposes). Backpatch to all versions because it is inconsistent with the documented behavior. Note that this could be an incompatibility for applications relying on the behavior contrary to the documentation. Author: Laurenz Albe Reviewed-by: Thomas Munro Discussion: https://postgr.es/m/77f24ea19ab802bc9bc60ddbb8977ee2d646aec1.camel%40cybertec.at Backpatch-through: 9.4
2019-06-30Don't read fields of a misaligned ExpandedObjectHeader or AnyArrayType.Noah Misch
UBSan complains about this. Instead, cast to a suitable type requiring only 4-byte alignment. DatumGetAnyArrayP() already assumes one can cast between AnyArrayType and ArrayType, so this doesn't introduce a new assumption. Back-patch to 9.5, where AnyArrayType was introduced. Reviewed by Tom Lane. Discussion: https://postgr.es/m/20190629210334.GA1244217@rfd.leadboat.com
2019-06-12Fix incorrect printing of queries with duplicated join names.Tom Lane
Given a query in which multiple JOIN nodes used the same alias (which'd necessarily be in different sub-SELECTs), ruleutils.c would assign the JOIN nodes distinct aliases for clarity ... but then it forgot to print the modified aliases when dumping the JOIN nodes themselves. This results in a dump/reload hazard for views, because the emitted query is flat-out incorrect: Vars will be printed with table names that have no referent. This has been wrong for a long time, so back-patch to all supported branches. Philip Dubé Discussion: https://postgr.es/m/CY4PR2101MB080246F2955FF58A6ED1FEAC98140@CY4PR2101MB0802.namprd21.prod.outlook.com
2019-06-10Don't access catalogs to validate GUCs when not connected to a DB.Andres Freund
Vignesh found this bug in the check function for default_table_access_method's check hook, but that was just copied from older GUCs. Investigation by Michael and me then found the bug in further places. When not connected to a database (e.g. in a walsender connection), we cannot perform (most) GUC checks that need database access. Even when only shared tables are needed, unless they're nailed (c.f. RelationCacheInitializePhase2()), they cannot be accessed without pg_class etc. being present. Fix by extending the existing IsTransactionState() checks to also check for MyDatabaseOid. Reported-By: Vignesh C, Michael Paquier, Andres Freund Author: Vignesh C, Andres Freund Discussion: https://postgr.es/m/CALDaNm1KXK9gbZfY-p_peRFm_XrBh1OwQO1Kk6Gig0c0fVZ2uw%40mail.gmail.com Backpatch: 9.4-
2019-05-12Fail pgwin32_message_to_UTF16() for SQL_ASCII messages.Noah Misch
The function had been interpreting SQL_ASCII messages as UTF8, throwing an error when they were invalid UTF8. The new behavior is consistent with pg_do_encoding_conversion(). This affects LOG_DESTINATION_STDERR and LOG_DESTINATION_EVENTLOG, which will send untranslated bytes to write() and ReportEventA(). On buildfarm member bowerbird, enabling log_connections caused an error whenever the role name was not valid UTF8. Back-patch to 9.4 (all supported versions). Discussion: https://postgr.es/m/20190512015615.GD1124997@rfd.leadboat.com
2019-05-06Use checkAsUser for selectivity estimator checks, if it's set.Dean Rasheed
In examine_variable() and examine_simple_variable(), when checking the user's table and column privileges to determine whether to grant access to the pg_statistic data, use checkAsUser for the privilege checks, if it's set. This will be the case if we're accessing the table via a view, to indicate that we should perform privilege checks as the view owner rather than the current user. This change makes this planner check consistent with the check in the executor, so the planner will be able to make use of statistics if the table is accessible via the view. This fixes a performance regression introduced by commit e2d4ef8de8, which affects queries against non-security barrier views in the case where the user doesn't have privileges on the underlying table, but the view owner does. Note that it continues to provide the same safeguards controlling access to pg_statistic for direct table access (in which case checkAsUser won't be set) and for security barrier views, because of the nearby checks on rte->security_barrier and rte->securityQuals. Back-patch to all supported branches because e2d4ef8de8 was. Dean Rasheed, reviewed by Jonathan Katz and Stephen Frost.
2019-05-06Fix security checks for selectivity estimation functions with RLS.Dean Rasheed
In commit e2d4ef8de8, security checks were added to prevent user-supplied operators from running over data from pg_statistic unless the user has table or column privileges on the table, or the operator is leakproof. For a table with RLS, however, checking for table or column privileges is insufficient, since that does not guarantee that the user has permission to view all of the column's data. Fix this by also checking for securityQuals on the RTE, and insisting that the operator be leakproof if there are any. Thus the leakproofness check will only be skipped if there are no securityQuals and the user has table or column privileges on the table -- i.e., only if we know that the user has access to all the data in the column. Back-patch to 9.5 where RLS was added. Dean Rasheed, reviewed by Jonathan Katz and Stephen Frost. Security: CVE-2019-10130
2019-05-02Fix reindexing of pg_class indexes some more.Tom Lane
Commits 3dbb317d3 et al failed under CLOBBER_CACHE_ALWAYS testing. Investigation showed that to reindex pg_class_oid_index, we must suppress accesses to the index (via SetReindexProcessing) before we call RelationSetNewRelfilenode, or at least before we do CommandCounterIncrement therein; otherwise, relcache reloads happening within the CCI may try to fetch pg_class rows using the index's new relfilenode value, which is as yet an empty file. Of course, the point of 3dbb317d3 was that that ordering didn't work either, because then RelationSetNewRelfilenode's own update of the index's pg_class row cannot access the index, should it need to. There are various ways we might have got around that, but Andres Freund came up with a brilliant solution: for a mapped index, we can really just skip the pg_class update altogether. The only fields it was actually changing were relpages etc, but it was just setting them to zeroes which is useless make-work. (Correct new values will be installed at the end of index build.) All pg_class indexes are mapped and probably always will be, so this eliminates the problem by removing work rather than adding it, always a pleasant outcome. Having taught RelationSetNewRelfilenode to do it that way, we can revert the code reordering in reindex_index. (But I left the moved setup code where it was; there seems no reason why it has to run without use of the old index. If you're trying to fix a busted pg_class index, you'll have had to disable system index use altogether to get this far.) Moreover, this means we don't need RelationSetIndexList at all, because reindex_relation's hacking to make "REINDEX TABLE pg_class" work is likewise now unnecessary. We'll leave that code in place in the back branches, but a follow-on patch will remove it in HEAD. In passing, do some minor cleanup for commit 5c1560606 (in HEAD only), notably removing a duplicate newrnode assignment. Patch by me, using a core idea due to Andres Freund. Back-patch to all supported branches, as 3dbb317d3 was. Discussion: https://postgr.es/m/28926.1556664156@sss.pgh.pa.us
2019-04-23Repair assorted issues in locale data extraction.Tom Lane
cache_locale_time (extraction of LC_TIME-related info) had never been taught the lessons we previously learned about extraction of info related to LC_MONETARY and LC_NUMERIC. Specifically, commit 95a777c61 taught PGLC_localeconv() that data coming out of localeconv() was in an encoding determined by the relevant locale, but we didn't realize that there's a similar issue with strftime(). And commit a4930e7ca hardened PGLC_localeconv() against errors occurring partway through, but failed to do likewise for cache_locale_time(). So, rearrange the latter function to perform encoding conversion and not risk failure while it's got the locales set to temporary values. This time around I also changed PGLC_localeconv() to treat it as FATAL if it can't restore the previous settings of the locale values. There is no reason (except possibly OOM) for that to fail, and proceeding with the wrong locale values seems like a seriously bad idea --- especially on Windows where we have to also temporarily change LC_CTYPE. Also, protect against the possibility that we can't identify the codeset reported for LC_MONETARY or LC_NUMERIC; rather than just failing, try to validate the data without conversion. The user-visible symptom this fixes is that if LC_TIME is set to a locale name that implies an encoding different from the database encoding, non-ASCII localized day and month names would be retrieved in the wrong encoding, leading to either unexpected encoding-conversion error reports or wrong output from to_char(). The other possible failure modes are unlikely enough that we've not seen reports of them, AFAIK. The encoding conversion problems do not manifest on Windows, since we'd already created special-case code to handle that issue there. Per report from Juan José Santamaría Flecha. Back-patch to all supported versions. Juan José Santamaría Flecha and Tom Lane Discussion: https://postgr.es/m/CAC+AXB22So5aZm2vZe+MChYXec7gWfr-n-SK-iO091R0P_1Tew@mail.gmail.com
2019-04-17postgresql.conf.sample: add proper defaults for include actionsBruce Momjian
Previously, include actions include_dir, include_if_exists, and include listed commented-out values which were not the defaults, which is inconsistent with other entries. Instead, replace them with '', which is the default value. Reported-by: Emanuel Araújo Discussion: https://postgr.es/m/CAMuTAkYMx6Q27wpELDR3_v9aG443y7ZjeXu15_+1nGUjhMWOJA@mail.gmail.com Backpatch-through: 9.4
2019-04-12Consistently test for in-use shared memory.Noah Misch
postmaster startup scrutinizes any shared memory segment recorded in postmaster.pid, exiting if that segment matches the current data directory and has an attached process. When the postmaster.pid file was missing, a starting postmaster used weaker checks. Change to use the same checks in both scenarios. This increases the chance of a startup failure, in lieu of data corruption, if the DBA does "kill -9 `head -n1 postmaster.pid` && rm postmaster.pid && pg_ctl -w start". A postmaster will no longer stop if shmat() of an old segment fails with EACCES. A postmaster will no longer recycle segments pertaining to other data directories. That's good for production, but it's bad for integration tests that crash a postmaster and immediately delete its data directory. Such a test now leaks a segment indefinitely. No "make check-world" test does that. win32_shmem.c already avoided all these problems. In 9.6 and later, enhance PostgresNode to facilitate testing. Back-patch to 9.4 (all supported versions). Reviewed (in earlier versions) by Daniel Gustafsson and Kyotaro HORIGUCHI. Discussion: https://postgr.es/m/20190408064141.GA2016666@rfd.leadboat.com
2019-04-05Revert "Consistently test for in-use shared memory."Noah Misch
This reverts commits 2f932f71d9f2963bbd201129d7b971c8f5f077fd, 16ee6eaf80a40007a138b60bb5661660058d0422 and 6f0e190056fe441f7cf788ff19b62b13c94f68f3. The buildfarm has revealed several bugs. Back-patch like the original commits. Discussion: https://postgr.es/m/20190404145319.GA1720877@rfd.leadboat.com
2019-04-03Consistently test for in-use shared memory.Noah Misch
postmaster startup scrutinizes any shared memory segment recorded in postmaster.pid, exiting if that segment matches the current data directory and has an attached process. When the postmaster.pid file was missing, a starting postmaster used weaker checks. Change to use the same checks in both scenarios. This increases the chance of a startup failure, in lieu of data corruption, if the DBA does "kill -9 `head -n1 postmaster.pid` && rm postmaster.pid && pg_ctl -w start". A postmaster will no longer recycle segments pertaining to other data directories. That's good for production, but it's bad for integration tests that crash a postmaster and immediately delete its data directory. Such a test now leaks a segment indefinitely. No "make check-world" test does that. win32_shmem.c already avoided all these problems. In 9.6 and later, enhance PostgresNode to facilitate testing. Back-patch to 9.4 (all supported versions). Reviewed by Daniel Gustafsson and Kyotaro HORIGUCHI. Discussion: https://postgr.es/m/20130911033341.GD225735@tornado.leadboat.com
2019-03-31Update HINT for pre-existing shared memory block.Noah Misch
One should almost always terminate an old process, not use a manual removal tool like ipcrm. Removal of the ipcclean script eleven years ago (39627b1ae680cba44f6e56ca5facec4fdbfe9495) and its non-replacement corroborate that manual shm removal is now a niche goal. Back-patch to 9.4 (all supported versions). Reviewed by Daniel Gustafsson and Kyotaro HORIGUCHI. Discussion: https://postgr.es/m/20180812064815.GB2301738@rfd.leadboat.com
2019-03-23Remove inadequate check for duplicate "xml" PI.Tom Lane
I failed to think about PIs starting with "xml". We don't really need this check at all, so just take it out. Oversight in commit 8d1dadb25 et al.
2019-03-23Revert strlen -> strnlen optimization pre-v11.Tom Lane
We don't have a src/port substitute for that function in older branches, so it fails on platforms lacking the function natively. Per buildfarm.
2019-03-23Accept XML documents when xmloption = content, as required by SQL:2006+.Tom Lane
Previously we were using the SQL:2003 definition, which doesn't allow this, but that creates a serious dump/restore gotcha: there is no setting of xmloption that will allow all valid XML data. Hence, switch to the 2006 definition. Since libxml doesn't accept <!DOCTYPE> directives in the mode we use for CONTENT parsing, the implementation is to detect <!DOCTYPE> in the input and switch to DOCUMENT parsing mode. This should not cost much, because <!DOCTYPE> should be close to the front of the input if it's there at all. It's possible that this causes the error messages for malformed input to be slightly different than they were before, if said input includes <!DOCTYPE>; but that does not seem like a big problem. In passing, buy back a few cycles in parsing of large XML documents by not doing strlen() of the whole input in parse_xml_decl(). Back-patch because dump/restore failures are not nice. This change shouldn't break any cases that worked before, so it seems safe to back-patch. Chapman Flack (revised a bit by me) Discussion: https://postgr.es/m/CAN-V+g-6JqUQEQZ55Q3toXEN6d5Ez5uvzL4VR+8KtvJKj31taw@mail.gmail.com
2019-03-10Disallow NaN as a value for floating-point GUCs.Tom Lane
None of the code that uses GUC values is really prepared for them to hold NaN, but parse_real() didn't have any defense against accepting such a value. Treat it the same as a syntax error. I haven't attempted to analyze the exact consequences of setting any of the float GUCs to NaN, but since they're quite unlikely to be good, this seems like a back-patchable bug fix. Note: we don't need an explicit test for +-Infinity because those will be rejected by existing range checks. I added a regression test for that in HEAD, but not older branches because the spelling of the value in the error message will be platform-dependent in branches where we don't always use port/snprintf.c. Discussion: https://postgr.es/m/1798.1552165479@sss.pgh.pa.us
2019-02-28Improve documentation of data_sync_retryMichael Paquier
Reflecting an updated parameter value requires a server restart, which was not mentioned in the documentation and in postgresql.conf.sample. Reported-by: Thomas Poty Discussion: https://postgr.es/m/15659-0cd812f13027a2d8@postgresql.org
2019-02-08Defend against null error message reported by libxml2.Tom Lane
While this isn't really supposed to happen, it can occur in OOM situations and perhaps others. Instead of crashing, substitute "(no message provided)". I didn't worry about localizing this text, since we aren't localizing anything else here; besides, if we're on the edge of OOM, it's unlikely gettext() would work. Report and fix by Sergio Conde Gómez in bug #15624. Discussion: https://postgr.es/m/15624-4dea54091a2864e6@postgresql.org
2019-01-30Fix a crash in logical replicationPeter Eisentraut
The bug was that determining which columns are part of the replica identity index using RelationGetIndexAttrBitmap() would run eval_const_expressions() on index expressions and predicates across all indexes of the table, which in turn might require a snapshot, but there wasn't one set, so it crashes. There were actually two separate bugs, one on the publisher and one on the subscriber. To trigger the bug, a table that is part of a publication or subscription needs to have an index with a predicate or expression that lends itself to constant expressions simplification. The fix is to avoid the constant expressions simplification in RelationGetIndexAttrBitmap(), so that it becomes safe to call in these contexts. The constant expressions simplification comes from the calls to RelationGetIndexExpressions()/RelationGetIndexPredicate() via BuildIndexInfo(). But RelationGetIndexAttrBitmap() calling BuildIndexInfo() is overkill. The latter just takes pg_index catalog information, packs it into the IndexInfo structure, which former then just unpacks again and throws away. We can just do this directly with less overhead and skip the troublesome calls to eval_const_expressions(). This also removes the awkward cross-dependency between relcache.c and index.c. Bug: #15114 Reported-by: Петър Славов <pet.slavov@gmail.com> Reviewed-by: Noah Misch <noah@leadboat.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://www.postgresql.org/message-id/flat/152110589574.1223.17983600132321618383@wrigleys.postgresql.org/
2019-01-21Flush relcache entries when their FKs are meddled withAlvaro Herrera
Back in commit 100340e2dcd0, we made relcache entries keep lists of the foreign keys applying to the relation -- but we forgot to update CacheInvalidateHeapTuple to flush those entries when new FKs got created or existing ones updated/deleted. No bugs appear to have been reported that would be explained by this ommission, but I noticed the problem while working on an unrelated bugfix which clearly showed it. Fix by adding relcache flush on relevant foreign key changes. Backpatch to 9.6, like the aforementioned commit. Discussion: https://postgr.es/m/201901211927.7mmhschxlejh@alvherre.pgsql Reviewed-by: Tom Lane
2018-11-24Fix float-to-integer coercions to handle edge cases correctly.Tom Lane
ftoi4 and its sibling coercion functions did their overflow checks in a way that looked superficially plausible, but actually depended on an assumption that the MIN and MAX comparison constants can be represented exactly in the float4 or float8 domain. That fails in ftoi4, ftoi8, and dtoi8, resulting in a possibility that values near the MAX limit will be wrongly converted (to negative values) when they need to be rejected. Also, because we compared before rounding off the fractional part, the other three functions threw errors for values that really ought to get rounded to the min or max integer value. Fix by doing rint() first (requiring an assumption that it handles NaN and Inf correctly; but dtoi8 and ftoi8 were assuming that already), and by comparing to values that should coerce to float exactly, namely INTxx_MIN and -INTxx_MIN. Also remove some random cosmetic discrepancies between these six functions. This back-patches commits cbdb8b4c0 and 452b637d4. In the 9.4 branch, also back-patch the portion of 62e2a8dc2 that added PG_INTnn_MIN and related constants to c.h, so that these functions can rely on them. Per bug #15519 from Victor Petrovykh. Patch by me; thanks to Andrew Gierth for analysis and discussion. Discussion: https://postgr.es/m/15519-4fc785b483201ff1@postgresql.org
2018-11-19PANIC on fsync() failure.Thomas Munro
On some operating systems, it doesn't make sense to retry fsync(), because dirty data cached by the kernel may have been dropped on write-back failure. In that case the only remaining copy of the data is in the WAL. A subsequent fsync() could appear to succeed, but not have flushed the data. That means that a future checkpoint could apparently complete successfully but have lost data. Therefore, violently prevent any future checkpoint attempts by panicking on the first fsync() failure. Note that we already did the same for WAL data; this change extends that behavior to non-temporary data files. Provide a GUC data_sync_retry to control this new behavior, for users of operating systems that don't eject dirty data, and possibly forensic/testing uses. If it is set to on and the write-back error was transient, a later checkpoint might genuinely succeed (on a system that does not throw away buffers on failure); if the error is permanent, later checkpoints will continue to fail. The GUC defaults to off, meaning that we panic. Back-patch to all supported releases. There is still a narrow window for error-loss on some operating systems: if the file is closed and later reopened and a write-back error occurs in the intervening time, but the inode has the bad luck to be evicted due to memory pressure before we reopen, we could miss the error. A later patch will address that with a scheme for keeping files with dirty data open at all times, but we judge that to be too complicated to back-patch. Author: Craig Ringer, with some adjustments by Thomas Munro Reported-by: Craig Ringer Reviewed-by: Robert Haas, Thomas Munro, Andres Freund Discussion: https://postgr.es/m/20180427222842.in2e4mibx45zdth5%40alap3.anarazel.de
2018-11-08Disallow setting client_min_messages higher than ERROR.Tom Lane
Previously it was possible to set client_min_messages to FATAL or PANIC, which had the effect of suppressing transmission of regular ERROR messages to the client. Perhaps that seemed like a useful option in the past, but the trouble with it is that it breaks guarantees that are explicitly made in our FE/BE protocol spec about how a query cycle can end. While libpq and psql manage to cope with the omission, that's mostly because they are not very bright; client libraries that have more semantic knowledge are likely to get confused. Notably, pgODBC doesn't behave very sanely. Let's fix this by getting rid of the ability to set client_min_messages above ERROR. In HEAD, just remove the FATAL and PANIC options from the set of allowed enum values for client_min_messages. (This change also affects trace_recovery_messages, but that's OK since these aren't useful values for that variable either.) In the back branches, there was concern that rejecting these values might break applications that are explicitly setting things that way. I'm pretty skeptical of that argument, but accommodate it by accepting these values and then internally setting the variable to ERROR anyway. In all branches, this allows a couple of tiny simplifications in the logic in elog.c, so do that. Also respond to the point that was made that client_min_messages has exactly nothing to do with the server's logging behavior, and therefore does not belong in the "When To Log" subsection of the documentation. The "Statement Behavior" subsection is a better match, so move it there. Jonah Harris and Tom Lane Discussion: https://postgr.es/m/7809.1541521180@sss.pgh.pa.us Discussion: https://postgr.es/m/15479-ef0f4cc2fd995ca2@postgresql.org
2018-11-06GUC: adjust effective_cache_size SQL descriptionsBruce Momjian
Follow on patch for commit 3e0f1a4741f564c1a2fa6e944729d6967355d8c7. Reported-by: Peter Eisentraut Discussion: https://postgr.es/m/369ec766-b947-51bd-4dad-6fb9e026439f@2ndquadrant.com Backpatch-through: 9.4
2018-11-02GUC: adjust effective_cache_size docs and SQL descriptionBruce Momjian
Clarify that effective_cache_size is both kernel buffers and shared buffers. Reported-by: nat@makarevitch.org Discussion: https://postgr.es/m/153685164808.22334.15432535018443165207@wrigleys.postgresql.org Backpatch-through: 9.3
2018-10-16Avoid statically allocating gmtsub()'s timezone workspace.Tom Lane
localtime.c's "struct state" is a rather large object, ~23KB. We were statically allocating one for gmtsub() to use to represent the GMT timezone, even though that function is not at all heavily used and is never reached in most backends. Let's malloc it on-demand, instead. This does pose the question of how to handle a malloc failure, but there's already a well-defined error report convention here, ie set errno and return NULL. We have but one caller of pg_gmtime in HEAD, and two in back branches, neither of which were troubling to check for error. Make them do so. The possible errors are sufficiently unlikely (out-of-range timestamp, and now malloc failure) that I think elog() is adequate. Back-patch to all supported branches to keep our copies of the IANA timezone code in sync. This particular change is in a stanza that already differs from upstream, so it's a wash for maintenance purposes --- but only as long as we keep the branches the same. Discussion: https://postgr.es/m/20181015200754.7y7zfuzsoux2c4ya@alap3.anarazel.de
2018-10-03MAXALIGN the target address where we store flattened value.Amit Kapila
The API (EOH_flatten_into) that flattens the expanded value representation expects the target address to be maxaligned. All it's usage adhere to that principle except when serializing datums for parallel query. Fix that usage. Diagnosed-by: Tom Lane Author: Tom Lane and Amit Kapila Backpatch-through: 9.6 Discussion: https://postgr.es/m/11629.1536550032@sss.pgh.pa.us
2018-10-02Fix corner-case failures in has_foo_privilege() family of functions.Tom Lane
The variants of these functions that take numeric inputs (OIDs or column numbers) are supposed to return NULL rather than failing on bad input; this rule reduces problems with snapshot skew when queries apply the functions to all rows of a catalog. has_column_privilege() had careless handling of the case where the table OID didn't exist. You might get something like this: select has_column_privilege(9999,'nosuchcol','select'); ERROR: column "nosuchcol" of relation "(null)" does not exist or you might get a crash, depending on the platform's printf's response to a null string pointer. In addition, while applying the column-number variant to a dropped column returned NULL as desired, applying the column-name variant did not: select has_column_privilege('mytable','........pg.dropped.2........','select'); ERROR: column "........pg.dropped.2........" of relation "mytable" does not exist It seems better to make this case return NULL as well. Also, the OID-accepting variants of has_foreign_data_wrapper_privilege, has_server_privilege, and has_tablespace_privilege didn't follow the principle of returning NULL for nonexistent OIDs. Superusers got TRUE, everybody else got an error. Per investigation of Jaime Casanova's report of a new crash in HEAD. These behaviors have been like this for a long time, so back-patch to all supported branches. Patch by me; thanks to Stephen Frost for discussion and review Discussion: https://postgr.es/m/CAJGNTeP=-6Gyqq5TN9OvYEydi7Fv1oGyYj650LGTnW44oAzYCg@mail.gmail.com
2018-09-24Fix over-allocation of space for array_out()'s result string.Tom Lane
array_out overestimated the space needed for its output, possibly by a very substantial amount if the array is multi-dimensional, because of wrong order of operations in the loop that counts the number of curly-brace pairs needed. While the output string is normally short-lived, this could still cause problems in extreme cases. An additional minor error was that it counted one more delimiter than is actually needed. Repair those errors, add an Assert that the space is now correctly calculated, and make some minor improvements in the comments. I also failed to resist the temptation to get rid of an integer modulus operation per array element; a simple comparison is sufficient. This bug dates clear back to Berkeley days, so back-patch to all supported versions. Keiichi Hirobe, minor additional work by me Discussion: https://postgr.es/m/CAH=EFxE9W0tRvQkixR2XJRRCToUYUEDkJZk6tnADXugPBRdcdg@mail.gmail.com
2018-09-23Initialize random() in bootstrap/stand-alone postgres and in initdb.Noah Misch
This removes a difference between the standard IsUnderPostmaster execution environment and that of --boot and --single. In a stand-alone backend, "SELECT random()" always started at the same seed. On a system capable of using posix shared memory, initdb could still conclude "selecting dynamic shared memory implementation ... sysv". Crashed --boot or --single postgres processes orphaned shared memory objects having names that collided with the not-actually-random names that initdb probed. The sysv fallback appeared after ten crashes of --boot or --single postgres. Since --boot and --single are rare in production use, systems used for PostgreSQL development are the principal candidate to notice this symptom. Back-patch to 9.3 (all supported versions). PostgreSQL 9.4 introduced dynamic shared memory, but 9.3 does share the "SELECT random()" problem. Reviewed by Tom Lane and Kyotaro HORIGUCHI. Discussion: https://postgr.es/m/20180915221546.GA3159382@rfd.leadboat.com
2018-09-12Repair bug in regexp split performance improvements.Andrew Gierth
Commit c8ea87e4b introduced a temporary conversion buffer for substrings extracted during regexp splits. Unfortunately the code that sized it was failing to ignore the effects of ignored degenerate regexp matches, so for regexp_split_* calls it could under-size the buffer in such cases. Fix, and add some regression test cases (though those will only catch the bug if run in a multibyte encoding). Backpatch to 9.3 as the faulty code was. Thanks to the PostGIS project, Regina Obe and Paul Ramsey for the report (via IRC) and assistance in analysis. Patch by me.
2018-09-07Limit depth of forced recursion for CLOBBER_CACHE_RECURSIVELY.Tom Lane
It's somewhat surprising that we got away with this before. (Actually, since nobody tests this routinely AFAIK, it might've been broken for awhile. But it's definitely broken in the wake of commit f868a8143.) It seems sufficient to limit the forced recursion to a small number of levels. Back-patch to all supported branches, like the preceding patch. Discussion: https://postgr.es/m/12259.1532117714@sss.pgh.pa.us
2018-08-28Avoid quadratic slowdown in regexp match/split functions.Andrew Gierth
regexp_matches, regexp_split_to_table and regexp_split_to_array all work by compiling a list of match positions as character offsets (NOT byte positions) in the source string. Formerly, they then used text_substr to extract the matched text; but in a multi-byte encoding, that counts the characters in the string, and the characters needed to reach the starting byte position, on every call. Accordingly, the performance degraded as the product of the input string length and the number of match positions, such that splitting a string of a few hundred kbytes could take many minutes. Repair by keeping the wide-character copy of the input string available (only in the case where encoding_max_length is not 1) after performing the match operation, and extracting substrings from that instead. This reduces the complexity to being linear in the number of result bytes, discounting the actual regexp match itself (which is not affected by this patch). In passing, remove cleanup using retail pfree() which was obsoleted by commit ff428cded (Feb 2008) which made cleanup of SRF multi-call contexts automatic. Also increase (to ~134 million) the maximum number of matches and provide an error message when it is reached. Backpatch all the way because this has been wrong forever. Analysis and patch by me; review by Kaiting Chen. Discussion: https://postgr.es/m/87pnyn55qh.fsf@news-spur.riddles.org.uk see also https://postgr.es/m/87lg996g4r.fsf@news-spur.riddles.org.uk
2018-08-15Clean up assorted misuses of snprintf()'s result value.Tom Lane
Fix a small number of places that were testing the result of snprintf() but doing so incorrectly. The right test for buffer overrun, per C99, is "result >= bufsize" not "result > bufsize". Some places were also checking for failure with "result == -1", but the standard only says that a negative value is delivered on failure. (Note that this only makes these places correct if snprintf() delivers C99-compliant results. But at least now these places are consistent with all the other places where we assume that.) Also, make psql_start_test() and isolation_start_test() check for buffer overrun while constructing their shell commands. There seems like a higher risk of overrun, with more severe consequences, here than there is for the individual file paths that are made elsewhere in the same functions, so this seemed like a worthwhile change. Also fix guc.c's do_serialize() to initialize errno = 0 before calling vsnprintf. In principle, this should be unnecessary because vsnprintf should have set errno if it returns a failure indication ... but the other two places this coding pattern is cribbed from don't assume that, so let's be consistent. These errors are all very old, so back-patch as appropriate. I think that only the shell command overrun cases are even theoretically reachable in practice, but there's not much point in erroneous error checks. Discussion: https://postgr.es/m/17245.1534289329@sss.pgh.pa.us
2018-07-31Further fixes for quoted-list GUC values in pg_dump and ruleutils.c.Tom Lane
Commits 742869946 et al turn out to be a couple bricks shy of a load. We were dumping the stored values of GUC_LIST_QUOTE variables as they appear in proconfig or setconfig catalog columns. However, although that quoting rule looks a lot like SQL-identifier double quotes, there are two critical differences: empty strings ("") are legal, and depending on which variable you're considering, values longer than NAMEDATALEN might be valid too. So the current technique fails altogether on empty-string list entries (as reported by Steven Winfield in bug #15248) and it also risks truncating file pathnames during dump/reload of GUC values that are lists of pathnames. To fix, split the stored value without any downcasing or truncation, and then emit each element as a SQL string literal. This is a tad annoying, because we now have three copies of the comma-separated-string splitting logic in varlena.c as well as a fourth one in dumputils.c. (Not to mention the randomly-different-from-those splitting logic in libpq...) I looked at unifying these, but it would be rather a mess unless we're willing to tweak the API definitions of SplitIdentifierString, SplitDirectoriesString, or both. That might be worth doing in future; but it seems pretty unsafe for a back-patched bug fix, so for now accept the duplication. Back-patch to all supported branches, as the previous fix was. Discussion: https://postgr.es/m/7585.1529435872@sss.pgh.pa.us
2018-07-28Document security implications of qualified names.Noah Misch
Commit 5770172cb0c9df9e6ce27c507b449557e5b45124 documented secure schema usage, and that advice suffices for using unqualified names securely. Document, in typeconv-func primarily, the additional issues that arise with qualified names. Back-patch to 9.3 (all supported versions). Reviewed by Jonathan S. Katz. Discussion: https://postgr.es/m/20180721012446.GA1840594@rfd.leadboat.com
2018-06-12Fix bugs in vacuum of shared rels, by keeping their relcache entries current.Andres Freund
When vacuum processes a relation it uses the corresponding relcache entry's relfrozenxid / relminmxid as a cutoff for when to remove tuples etc. Unfortunately for nailed relations (i.e. critical system catalogs) bugs could frequently lead to the corresponding relcache entry being stale. This set of bugs could cause actual data corruption as vacuum would potentially not remove the correct row versions, potentially reviving them at a later point. After 699bf7d05c some corruptions in this vein were prevented, but the additional error checks could also trigger spuriously. Examples of such errors are: ERROR: found xmin ... from before relfrozenxid ... and ERROR: found multixact ... from before relminmxid ... To be caused by this bug the errors have to occur on system catalog tables. The two bugs are: 1) Invalidations for nailed relations were ignored, based on the theory that the relcache entry for such tables doesn't change. Which is largely true, except for fields like relfrozenxid etc. This means that changes to relations vacuumed in other sessions weren't picked up by already existing sessions. Luckily autovacuum doesn't have particularly longrunning sessions. 2) For shared *and* nailed relations, the shared relcache init file was never invalidated while running. That means that for such tables (e.g. pg_authid, pg_database) it's not just already existing sessions that are affected, but even new connections are as well. That explains why the reports usually were about pg_authid et. al. To fix 1), revalidate the rd_rel portion of a relcache entry when invalid. This implies a bit of extra complexity to deal with bootstrapping, but it's not too bad. The fix for 2) is simpler, simply always remove both the shared and local init files. Author: Andres Freund Reviewed-By: Alvaro Herrera Discussion: https://postgr.es/m/20180525203736.crkbg36muzxrjj5e@alap3.anarazel.de https://postgr.es/m/CAMa1XUhKSJd98JW4o9StWPrfS=11bPgG+_GDMxe25TvUY4Sugg@mail.gmail.com https://postgr.es/m/CAKMFJucqbuoDRfxPDX39WhA3vJyxweRg_zDVXzncr6+5wOguWA@mail.gmail.com https://postgr.es/m/CAGewt-ujGpMLQ09gXcUFMZaZsGJC98VXHEFbF-tpPB0fB13K+A@mail.gmail.com Backpatch: 9.3-
2018-05-09Update time zone data files to tzdata release 2018e.Tom Lane
DST law changes in North Korea. Redefinition of "daylight savings" in Ireland, as well as for some past years in Namibia and Czechoslovakia. Additional historical corrections for Czechoslovakia. With this change, the IANA database models Irish timekeeping as following "standard time" in summer, and "daylight savings" in winter, so that the daylight savings offset is one hour behind standard time not one hour ahead. This does not change their UTC offset (+1:00 in summer, 0:00 in winter) nor their timezone abbreviations (IST in summer, GMT in winter), though now "IST" is more correctly read as "Irish Standard Time" not "Irish Summer Time". However, the "is_dst" column in the pg_timezone_names view will now be true in winter and false in summer for the Europe/Dublin zone. Similar changes were made for Namibia between 1994 and 2017, and for Czechoslovakia between 1946 and 1947. So far as I can find, no Postgres internal logic cares about which way tm_isdst is reported; in particular, since commit b2cbced9e we do not rely on it to decide how to interpret ambiguous timestamps during DST transitions. So I don't think this change will affect any Postgres behavior other than the timezone-view outputs. Discussion: https://postgr.es/m/30996.1525445902@sss.pgh.pa.us
2018-05-02Revert back-branch changes in power()'s behavior for NaN inputs.Tom Lane
Per discussion, the value of fixing these bugs in the back branches doesn't outweigh the downsides of changing corner-case behavior in a minor release. Hence, revert commits 217d8f3a1 and 4d864de48 in the v10 branch and the corresponding commits in 9.3-9.6. Discussion: https://postgr.es/m/75DB81BEEA95B445AE6D576A0A5C9E936A73E741@BPXM05GP.gisp.nec.co.jp
2018-04-29Avoid wrong results for power() with NaN input on more platforms.Tom Lane
Buildfarm results show that the modern POSIX rule that 1 ^ NaN = 1 is not honored on *BSD until relatively recently, and really old platforms don't believe that NaN ^ 0 = 1 either. (This is unsurprising, perhaps, since SUSv2 doesn't require either behavior.) In hopes of getting to platform independent behavior, let's deal with all the NaN-input cases explicitly in dpow(). Note that numeric_power() doesn't know either of these special cases. But since that behavior is platform-independent, I think it should be addressed separately, and probably not back-patched. Discussion: https://postgr.es/m/75DB81BEEA95B445AE6D576A0A5C9E936A73E741@BPXM05GP.gisp.nec.co.jp
2018-04-29Avoid wrong results for power() with NaN input on some platforms.Tom Lane
Per spec, the result of power() should be NaN if either input is NaN. It appears that on some versions of Windows, the libc function does return NaN, but it also sets errno = EDOM, confusing our code that attempts to work around shortcomings of other platforms. Hence, add guard tests to avoid substituting a wrong result for the right one. It's been like this for a long time (and the odd behavior only appears in older MSVC releases, too) so back-patch to all supported branches. Dang Minh Huong, reviewed by David Rowley Discussion: https://postgr.es/m/75DB81BEEA95B445AE6D576A0A5C9E936A73E741@BPXM05GP.gisp.nec.co.jp
2018-03-28Fix actual and potential double-frees around tuplesort usage.Tom Lane
tuplesort_gettupleslot() passed back tuples allocated in the tuplesort's own memory context, even when the caller was responsible to free them. This created a double-free hazard, because some callers might destroy the tuplesort object (via tuplesort_end) before trying to clean up the last returned tuple. To avoid this, change the API to specify that the tuple is allocated in the caller's memory context. v10 and HEAD already did things that way, but in 9.5 and 9.6 this is a live bug that can demonstrably cause crashes with some grouping-set usages. In 9.5 and 9.6, this requires doing an extra tuple copy in some cases, which is unfortunate. But the amount of refactoring needed to avoid it seems excessive for a back-patched change, especially since the cases where an extra copy happens are less performance-critical. Likewise change tuplesort_getdatum() to return pass-by-reference Datums in the caller's context not the tuplesort's context. There seem to be no live bugs among its callers, but clearly the same sort of situation could happen in future. For other tuplesort fetch routines, continue to allocate the memory in the tuplesort's context. This is a little inconsistent with what we now do for tuplesort_gettupleslot() and tuplesort_getdatum(), but that's preferable to adding new copy overhead in the back branches where it's clearly unnecessary. These other fetch routines provide the weakest possible guarantees about tuple memory lifespan from v10 on, anyway, so this actually seems more consistent overall. Adjust relevant comments to reflect these API redefinitions. Arguably, we should change the pre-9.5 branches as well, but since there are no known failure cases there, it seems not worth the risk. Peter Geoghegan, per report from Bernd Helmle. Reviewed by Kyotaro Horiguchi; thanks also to Andreas Seltenreich for extracting a self-contained test case. Discussion: https://postgr.es/m/1512661638.9720.34.camel@oopsware.de
2018-03-23Fix make rules that generate multiple output files.Tom Lane
For years, our makefiles have correctly observed that "there is no correct way to write a rule that generates two files". However, what we did is to provide empty rules that "generate" the secondary output files from the primary one, and that's not right either. Depending on the details of the creating process, the primary file might end up timestamped later than one or more secondary files, causing subsequent make runs to consider the secondary file(s) out of date. That's harmless in a plain build, since make will just re-execute the empty rule and nothing happens. But it's fatal in a VPATH build, since make will expect the secondary file to be rebuilt in the build directory. This would manifest as "file not found" failures during VPATH builds from tarballs, if we were ever unlucky enough to ship a tarball with apparently out-of-date secondary files. (It's not clear whether that has ever actually happened, but it definitely could.) To ensure that secondary output files have timestamps >= their primary's, change our makefile convention to be that we provide a "touch $@" action not an empty rule. Also, make sure that this rule actually gets invoked during a distprep run, else the hazard remains. It's been like this a long time, so back-patch to all supported branches. In HEAD, I skipped the changes in src/backend/catalog/Makefile, because those rules are due to get replaced soon in the bootstrap data format patch, and there seems no need to create a merge issue for that patch. If for some reason we fail to land that patch in v11, we'll need to back-fill the changes in that one makefile from v10. Discussion: https://postgr.es/m/18556.1521668179@sss.pgh.pa.us
2018-03-21Fix mishandling of quoted-list GUC values in pg_dump and ruleutils.c.Tom Lane
Code that prints out the contents of setconfig or proconfig arrays in SQL format needs to handle GUC_LIST_QUOTE variables differently from other ones, because for those variables, flatten_set_variable_args() already applied a layer of quoting. The value can therefore safely be printed as-is, and indeed must be, or flatten_set_variable_args() will muck it up completely on reload. For all other GUC variables, it's necessary and sufficient to quote the value as a SQL literal. We'd recognized the need for this long ago, but mis-analyzed the need slightly, thinking that all GUC_LIST_INPUT variables needed the special treatment. That's actually wrong, since a valid value of a LIST variable might include characters that need quoting, although no existing variables accept such values. More to the point, we hadn't made any particular effort to keep the various places that deal with this up-to-date with the set of variables that actually need special treatment, meaning that we'd do the wrong thing with, for example, temp_tablespaces values. This affects dumping of SET clauses attached to functions, as well as ALTER DATABASE/ROLE SET commands. In ruleutils.c we can fix it reasonably honestly by exporting a guc.c function that allows discovering the flags for a given GUC variable. But pg_dump doesn't have easy access to that, so continue the old method of having a hard-wired list of affected variable names. At least we can fix it to have just one list not two, and update the list to match current reality. A remaining problem with this is that it only works for built-in GUC variables. pg_dump's list obvious knows nothing of third-party extensions, and even the "ask guc.c" method isn't bulletproof since the relevant extension might not be loaded. There's no obvious solution to that, so for now, we'll just have to discourage extension authors from inventing custom GUCs that need GUC_LIST_QUOTE. This has been busted for a long time, so back-patch to all supported branches. Michael Paquier and Tom Lane, reviewed by Kyotaro Horiguchi and Pavel Stehule Discussion: https://postgr.es/m/20180111064900.GA51030@paquier.xyz
2018-03-19Fix some corner-case issues in REFRESH MATERIALIZED VIEW CONCURRENTLY.Tom Lane
refresh_by_match_merge() has some issues in the way it builds a SQL query to construct the "diff" table: 1. It doesn't require the selected unique index(es) to be indimmediate. 2. It doesn't pay attention to the particular equality semantics enforced by a given index, but just assumes that they must be those of the column datatype's default btree opclass. 3. It doesn't check that the indexes are btrees. 4. It's insufficiently careful to ensure that the parser will pick the intended operator when parsing the query. (This would have been a security bug before CVE-2018-1058.) 5. It's not careful about indexes on system columns. The way to fix #4 is to make use of the existing code in ri_triggers.c for generating an arbitrary binary operator clause. I chose to move that to ruleutils.c, since that seems a more reasonable place to be exporting such functionality from than ri_triggers.c. While #1, #3, and #5 are just latent given existing feature restrictions, and #2 doesn't arise in the core system for lack of alternate opclasses with different equality behaviors, #4 seems like an issue worth back-patching. That's the bulk of the change anyway, so just back-patch the whole thing to 9.4 where this code was introduced. Discussion: https://postgr.es/m/13836.1521413227@sss.pgh.pa.us
2018-03-11Fix improper uses of canonicalize_qual().Tom Lane
One of the things canonicalize_qual() does is to remove constant-NULL subexpressions of top-level AND/OR clauses. It does that on the assumption that what it's given is a top-level WHERE clause, so that NULL can be treated like FALSE. Although this is documented down inside a subroutine of canonicalize_qual(), it wasn't mentioned in the documentation of that function itself, and some callers hadn't gotten that memo. Notably, commit d007a9505 caused get_relation_constraints() to apply canonicalize_qual() to CHECK constraints. That allowed constraint exclusion to misoptimize situations in which a CHECK constraint had a provably-NULL subclause, as seen in the regression test case added here, in which a child table that should be scanned is not. (Although this thinko is ancient, the test case doesn't fail before 9.2, for reasons I've not bothered to track down in detail. There may be related cases that do fail before that.) More recently, commit f0e44751d added an independent bug by applying canonicalize_qual() to index expressions, which is even sillier since those might not even be boolean. If they are, though, I think this could lead to making incorrect index entries for affected index expressions in v10. I haven't attempted to prove that though. To fix, add an "is_check" parameter to canonicalize_qual() to specify whether it should assume WHERE or CHECK semantics, and make it perform NULL-elimination accordingly. Adjust the callers to apply the right semantics, or remove the call entirely in cases where it's not known that the expression has one or the other semantics. I also removed the call in some cases involving partition expressions, where it should be a no-op because such expressions should be canonical already ... and was a no-op, independently of whether it could in principle have done something, because it was being handed the qual in implicit-AND format which isn't what it expects. In HEAD, add an Assert to catch that type of mistake in future. This represents an API break for external callers of canonicalize_qual(). While that's intentional in HEAD to make such callers think about which case applies to them, it seems like something we probably wouldn't be thanked for in released branches. Hence, in released branches, the extra parameter is added to a new function canonicalize_qual_ext(), and canonicalize_qual() is a wrapper that retains its old behavior. Patch by me with suggestions from Dean Rasheed. Back-patch to all supported branches. Discussion: https://postgr.es/m/24475.1520635069@sss.pgh.pa.us
2018-03-03Fix assorted issues in convert_to_scalar().Tom Lane
If convert_to_scalar is passed a pair of datatypes it can't cope with, its former behavior was just to elog(ERROR). While this is OK so far as the core code is concerned, there's extension code that would like to use scalarltsel/scalargtsel/etc as selectivity estimators for operators that work on non-core datatypes, and this behavior is a show-stopper for that use-case. If we simply allow convert_to_scalar to return FALSE instead of outright failing, then the main logic of scalarltsel/scalargtsel will work fine for any operator that behaves like a scalar inequality comparison. The lack of conversion capability will mean that we can't estimate to better than histogram-bin-width precision, since the code will effectively assume that the comparison constant falls at the middle of its bin. But that's still a lot better than nothing. (Someday we should provide a way for extension code to supply a custom version of convert_to_scalar, but today is not that day.) While poking at this issue, we noted that the existing code for handling type bytea in convert_to_scalar is several bricks shy of a load. It assumes without checking that if the comparison value is type bytea, the bounds values are too; in the worst case this could lead to a crash. It also fails to detoast the input values, so that the comparison result is complete garbage if any input is toasted out-of-line, compressed, or even just short-header. I'm not sure how often such cases actually occur --- the bounds values, at least, are probably safe since they are elements of an array and hence can't be toasted. But that doesn't make this code OK. Back-patch to all supported branches, partly because author requested that, but mostly because of the bytea bugs. The change in API for the exposed routine convert_network_to_scalar() is theoretically a back-patch hazard, but it seems pretty unlikely that any third-party code is calling that function directly. Tomas Vondra, with some adjustments by me Discussion: https://postgr.es/m/b68441b6-d18f-13ab-b43b-9a72188a4e02@2ndquadrant.com