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2024-08-09Fix "failed to find plan for subquery/CTE" errors in EXPLAIN.Tom Lane
To deparse a reference to a field of a RECORD-type output of a subquery, EXPLAIN normally digs down into the subquery's plan to try to discover exactly which anonymous RECORD type is meant. However, this can fail if the subquery has been optimized out of the plan altogether on the grounds that no rows could pass the WHERE quals, which has been possible at least since 3fc6e2d7f. There isn't anything remaining in the plan tree that would help us, so fall back to printing the field name as "fN" for the N'th column of the record. (This will actually be the right thing some of the time, since it matches the column names we assign to RowExprs.) In passing, fix a comment typo in create_projection_plan, which I noticed while experimenting with an alternative fix for this. Per bug #18576 from Vasya B. Back-patch to all supported branches. Richard Guo and Tom Lane Discussion: https://postgr.es/m/18576-9feac34e132fea9e@postgresql.org
2024-08-05Restrict accesses to non-system views and foreign tables during pg_dump.Masahiko Sawada
When pg_dump retrieves the list of database objects and performs the data dump, there was possibility that objects are replaced with others of the same name, such as views, and access them. This vulnerability could result in code execution with superuser privileges during the pg_dump process. This issue can arise when dumping data of sequences, foreign tables (only 13 or later), or tables registered with a WHERE clause in the extension configuration table. To address this, pg_dump now utilizes the newly introduced restrict_nonsystem_relation_kind GUC parameter to restrict the accesses to non-system views and foreign tables during the dump process. This new GUC parameter is added to back branches too, but these changes do not require cluster recreation. Back-patch to all supported branches. Reviewed-by: Noah Misch Security: CVE-2024-7348 Backpatch-through: 12
2024-07-23Detect integer overflow in array_set_slice().Nathan Bossart
When provided an empty initial array, array_set_slice() fails to check for overflow when computing the new array's dimensions. While such overflows are ordinarily caught by ArrayGetNItems(), commands with the following form are accepted: INSERT INTO t (i[-2147483648:2147483647]) VALUES ('{}'); To fix, perform the hazardous computations using overflow-detecting arithmetic routines. As with commit 18b585155a, the added test cases generate errors that include a platform-dependent value, so we again use psql's VERBOSITY parameter to suppress printing the message text. Reported-by: Alexander Lakhin Author: Joseph Koshakow Reviewed-by: Jian He Discussion: https://postgr.es/m/31ad2cd1-db94-bdb3-f91a-65ffdb4bef95%40gmail.com Backpatch-through: 12
2024-07-19Add overflow checks to money type.Nathan Bossart
None of the arithmetic functions for the the money type handle overflow. This commit introduces several helper functions with overflow checking and makes use of them in the money type's arithmetic functions. Fixes bug #18240. Reported-by: Alexander Lakhin Author: Joseph Koshakow Discussion: https://postgr.es/m/18240-c5da758d7dc1ecf0%40postgresql.org Discussion: https://postgr.es/m/CAAvxfHdBPOyEGS7s%2Bxf4iaW0-cgiq25jpYdWBqQqvLtLe_t6tw%40mail.gmail.com Backpatch-through: 12
2024-07-15Fix bad indentation introduced in 43cd30bcd1cAndres Freund
Oops. Reported-by: Nathan Bossart <nathandbossart@gmail.com> Discussion: https://postgr.es/m/ZpVZB9rH5tHllO75@nathan Backpatch: 12-, like 43cd30bcd1c
2024-07-15Fix type confusion in guc_var_compare()Andres Freund
Before this change guc_var_compare() cast the input arguments to const struct config_generic *. That's not quite right however, as the input on one side is often just a char * on one side. Instead just use char *, the first field in config_generic. This fixes a -Warray-bounds warning with some versions of gcc. While the warning is only known to be triggered for <= 15, the issue the warning points out seems real, so apply the fix everywhere. Author: Nazir Bilal Yavuz <byavuz81@gmail.com> Reported-by: Erik Rijkers <er@xs4all.nl> Suggested-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/a74a1a0d-0fd2-3649-5224-4f754e8f91aa%40xs4all.nl
2024-07-10Make our back branches compatible with libxml2 2.13.x.Tom Lane
This back-patches HEAD commits 066e8ac6e, 6082b3d5d, e7192486d, and 896cd266f into supported branches. Changes: * Use xmlAddChildList not xmlAddChild in XMLSERIALIZE (affects v16 and up only). This was a flat-out coding mistake that we got away with due to lax checking in previous versions of xmlAddChild. * Use xmlParseInNodeContext not xmlParseBalancedChunkMemory. This is to dodge a bug in xmlParseBalancedChunkMemory in libxm2 releases 2.13.0-2.13.2. While that bug is now fixed upstream and will probably never be seen in any production-oriented distro, it is currently a problem on some more-bleeding-edge-friendly platforms. * Suppress "chunk is not well balanced" errors from libxml2, unless it is the only error. This eliminates an error-reporting discrepancy between 2.13 and older releases. This error is almost always redundant with previous errors, if not flat-out inappropriate, which is why 2.13 changed the behavior and why nobody's likely to miss it. Erik Wienhold and Tom Lane, per report from Frank Streitzig. Discussion: https://postgr.es/m/trinity-b0161630-d230-4598-9ebc-7a23acdb37cb-1720186432160@3c-app-gmx-bap25 Discussion: https://postgr.es/m/trinity-361ba18b-541a-4fe7-bc63-655ae3a7d599-1720259822452@3c-app-gmx-bs01
2024-07-08Fix scale clamping in numeric round() and trunc().Dean Rasheed
The numeric round() and trunc() functions clamp the scale argument to the range between +/- NUMERIC_MAX_RESULT_SCALE (2000), which is much smaller than the actual allowed range of type numeric. As a result, they return incorrect results when asked to round/truncate more than 2000 digits before or after the decimal point. Fix by using the correct upper and lower scale limits based on the actual allowed (and documented) range of type numeric. While at it, use the new NUMERIC_WEIGHT_MAX constant instead of SHRT_MAX in all other overflow checks, and fix a comment thinko in power_var() introduced by e54a758d24 -- the minimum value of ln_dweight is -NUMERIC_DSCALE_MAX (-16383), not -SHRT_MAX, though this doesn't affect the point being made in the comment, that the resulting local_rscale value may exceed NUMERIC_MAX_DISPLAY_SCALE (1000). Back-patch to all supported branches. Dean Rasheed, reviewed by Joel Jacobson. Discussion: https://postgr.es/m/CAEZATCXB%2BrDTuMjhK5ZxcouufigSc-X4tGJCBTMpZ3n%3DxxQuhg%40mail.gmail.com
2024-06-27Cope with inplace update making catcache stale during TOAST fetch.Noah Misch
This extends ad98fb14226ae6456fbaed7990ee7591cbe5efd2 to invals of inplace updates. Trouble requires an inplace update of a catalog having a TOAST table, so only pg_database was at risk. (The other catalog on which core code performs inplace updates, pg_class, has no TOAST table.) Trouble would require something like the inplace-inval.spec test. Consider GRANT ... ON DATABASE fetching a stale row from cache and discarding a datfrozenxid update that vac_truncate_clog() has already relied upon. Back-patch to v12 (all supported versions). Reviewed (in an earlier version) by Robert Haas. Discussion: https://postgr.es/m/20240114201411.d0@rfd.leadboat.com Discussion: https://postgr.es/m/20240512232923.aa.nmisch@google.com
2024-06-27Avoid crashing when a JIT-inlined backend function throws an error.Tom Lane
errfinish() assumes that the __FUNC__ and __FILE__ arguments it's passed are compile-time constant strings that can just be pointed to rather than physically copied. However, it's possible for LLVM to generate code in which those pointers point into a dynamically loaded code segment. If that segment gets unloaded before we're done with the ErrorData struct, we have dangling pointers that will lead to SIGSEGV. In simple cases that won't happen, because we won't unload LLVM code before end of transaction. But it's possible to happen if the error is thrown within end-of-transaction code run by _SPI_commit or _SPI_rollback, because since commit 2e517818f those functions clean up by ending the transaction and starting a new one. Rather than fixing this by adding pstrdup() overhead to every elog/ereport sequence, let's fix it by copying the risky pointers in CopyErrorData(). That solves it for _SPI_commit/_SPI_rollback because they use that function to preserve the error data across the transaction end/restart sequence; and it seems likely that any other code doing something similar would need to do that too. I'm suspicious that this behavior amounts to an LLVM bug (or a bug in our use of it?), because it implies that string constant references that should be pointer-equal according to a naive understanding of C semantics will sometimes not be equal. However, even if it is a bug and someday gets fixed, we'll have to cope with the current behavior for a long time to come. Report and patch by me. Back-patch to all supported branches. Discussion: https://postgr.es/m/1565654.1719425368@sss.pgh.pa.us
2024-06-13Fix parsing of ignored operators in websearch_to_tsquery().Tom Lane
The manual says clearly that punctuation in the input of websearch_to_tsquery() is ignored, except for the special cases of dashes and quotes. However, this failed for cases like "(foo bar) or something", or in general an ISOPERATOR character in front of the "or". We'd switch back to WAITOPERAND state, then ignore the operator character while remaining in that state, and then reach the "or" in WAITOPERAND state which (intentionally) makes us treat it as data. The fix is simple enough: if we see an ISOPERATOR character while in WAITOPERATOR state, we have to skip it while staying in that state. (We don't need to worry about other punctuation characters: those will be consumed as though they were words, but then rejected by lexizing.) In v14 and up (since commit eb086056f) we can simplify the code a bit more too, because there is no longer a reason for the WAITOPERAND state to distinguish between quoted and unquoted operands. Per bug #18479 from Manos Emmanouilidis. Back-patch to all supported branches. Discussion: https://postgr.es/m/18479-d9b46e2fc242c33e@postgresql.org
2024-04-28Detect more overflows in timestamp[tz]_pl_interval.Tom Lane
In commit 25cd2d640 I (tgl) opined that "The additions of the months and microseconds fields could also overflow, of course. However, I believe we need no additional checks there; the existing range checks should catch such cases". This is demonstrably wrong however for the microseconds field, and given that discovery it seems prudent to be paranoid about the months addition as well. Report and patch by Joseph Koshakow. As before, back-patch to all supported branches. (However, the test case doesn't work before v15 because we didn't allow wider-than-int32 numbers in interval literals. A variant test could probably be built that fits within that restriction, but it didn't seem worth the trouble.) Discussion: https://postgr.es/m/CAAvxfHf77sRHKoEzUw9_cMYSpbpNS2C+J_+8Dq4+0oi8iKopeA@mail.gmail.com
2024-04-15Fix type-checking of RECORD-returning functions in FROM, redux.Tom Lane
Commit 2ed8f9a01 intended to institute a policy that if a RangeTblFunction has a coldeflist, then the function return type is certainly RECORD, and we should use the coldeflist as the source of truth about what the columns of the record type are. When the original function has been folded to a constant, inspection of the constant might give a different answer. This situation will lead to a tuple-type-mismatch error at execution, but up until that point we need to consistently believe the coldeflist, or we'll have problems from different bits of code reaching different conclusions. expandRTE didn't get that memo though, and would try to produce a tupdesc based on the constant in this situation, leading to an assertion failure. (Desultory testing suggests that non-assert builds often manage to give the expected error, although I also saw a "cache lookup failed for type 0" error, and it seems at least possible that a crash could happen.) Some other callers of get_expr_result_type and get_expr_result_tupdesc were also being incautious about this. While none of them seem to have actual bugs, they're working harder than necessary in this case, besides which it seems safest to have an explicit policy of not using those functions on an RTE with a coldeflist. Adjust the code accordingly, and add commentary to funcapi.c about this policy. Also fix an obsolete comment that claimed "get_expr_result_type() doesn't know how to extract type info from a RECORD constant". That hasn't been true since commit d57534740. Per bug #18422 from Alexander Lakhin. As with the previous commit, back-patch to all supported branches. Discussion: https://postgr.es/m/18422-89ca86c8eac5246d@postgresql.org
2024-03-26Allow "make check"-style testing to work with musl C library.Tom Lane
The musl dynamic linker saves a pointer to the process' environment value of LD_LIBRARY_PATH very early in startup. When we move/clobber the environment to make more room for ps status strings, we clobber that value and thereby prevent libraries from being found via LD_LIBRARY_PATH, which breaks the use of a temporary installation for testing purposes. To fix, stop collecting usable space for ps status if we notice that the variable we are about to clobber is LD_LIBRARY_PATH. This will result in some reduction in how long the ps status can be, but it's only likely to occur in temporary test contexts, so it doesn't seem like a big problem. In any case, we don't have to do it if we see we are on glibc, which surely is where the majority of our Linux testing is done. Thomas Munro, Bruce Momjian, and Tom Lane, per report from Wolfgang Walther. Back-patch to all supported branches, with the hope that we'll set up a buildfarm animal to test on this platform. Discussion: https://postgr.es/m/fddd1cd6-dc16-40a2-9eb5-d7fef2101488@technowledgy.de
2024-03-25Clarify comment for LogicalTapeSetBlocks().Jeff Davis
Discussion: https://postgr.es/m/1229327.1711160246@sss.pgh.pa.us Backpatch-through: 13
2024-03-23Remove incorrect Assert introduced in c8aeaf3ab.Jeff Davis
Already removed incidentally in version 15 (c4649cce3), so this commit is only applied to versions 13 and 14. The comment above is misleading in all versions 13 and later, so that will be fixed in a separate commit. Discussion: https://postgr.es/m/cfd84cb8-12fe-433a-a4bb-f460a4515f9c.zhaotinghai.zth%40alibaba-inc.com Reported-by: Tinghai Zhao Backpatch-through: 13
2024-03-11Backpatch missing check_stack_depth() to some recursive functionsAlexander Korotkov
Backpatch changes from d57b7cc333, 75bcba6cbd to all supported branches per proposal of Egor Chindyaskin. Discussion: https://postgr.es/m/DE5FD776-A8CD-4378-BCFA-3BF30F1F6D60%40mail.ru
2024-03-07Revert "Fix parallel-safety check of expressions and predicate for index builds"Michael Paquier
This reverts commit eae7be600be7, following a discussion with Tom Lane, due to concerns that this impacts the decisions made by the planner for the number of workers spawned based on the inlining and const-folding of index expressions and predicate for cases that would have worked until this commit. Discussion: https://postgr.es/m/162802.1709746091@sss.pgh.pa.us Backpatch-through: 12
2024-03-06Fix parallel-safety check of expressions and predicate for index buildsMichael Paquier
As coded, the planner logic that calculates the number of parallel workers to use for a parallel index build uses expressions and predicates from the relcache, which are flattened for the planner by eval_const_expressions(). As reported in the bug, an immutable parallel-unsafe function flattened in the relcache would become a Const, which would be considered as parallel-safe, even if the predicate or the expressions including the function are not safe in parallel workers. Depending on the expressions or predicate used, this could cause the parallel build to fail. Tests are included that check parallel index builds with parallel-unsafe predicate and expressions. Two routines are added to lsyscache.h to be able to retrieve expressions and predicate of an index from its pg_index data. Reported-by: Alexander Lakhin Author: Tender Wang Reviewed-by: Jian He, Michael Paquier Discussion: https://postgr.es/m/CAHewXN=UaAaNn9ruHDH3Os8kxLVmtWqbssnf=dZN_s9=evHUFA@mail.gmail.com Backpatch-through: 12
2024-02-29Fix integer underflow in shared memory debuggingDaniel Gustafsson
dsa_dump would print a large negative number instead of zero for segment bin 0. Fix by explicitly checking for underflow and add special case for bin 0. Backpatch to all supported versions. Author: Ian Ilyasov <ianilyasov@outlook.com> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Discussion: https://postgr.es/m/GV1P251MB1004E0D09D117D3CECF9256ECD502@GV1P251MB1004.EURP251.PROD.OUTLOOK.COM Backpatch-through: v12
2024-02-28Fix mis-rounding and overflow hazards in date_bin().Tom Lane
In the case where the target timestamp is before the origin timestamp and their difference is already an exact multiple of the stride, the code incorrectly subtracted the stride anyway. Also detect several integer-overflow cases that previously produced bogus results. (The submitted patch tried to avoid overflow, but I'm not convinced it's right, and problematic cases are so far out of the plausibly-useful range that they don't seem worth sweating over. Let's just use overflow-detecting arithmetic and throw errors.) timestamp_bin() and timestamptz_bin() are basically identical and so had identical bugs. Fix both. Report and patch by Moaaz Assali, adjusted some by me. Back-patch to v14 where date_bin() was introduced. Discussion: https://postgr.es/m/CALkF+nvtuas-2kydG-WfofbRSJpyODAJWun==W-yO5j2R4meqA@mail.gmail.com
2024-02-15Doc: improve a couple of comments in postgresql.conf.sample.Tom Lane
Clarify comments associated with max_parallel_workers and related settings. Per bug #18343 from Christopher Kline. Discussion: https://postgr.es/m/18343-3a5e903d1d3692ab@postgresql.org
2024-02-09Remove race condition in pg_get_expr().Tom Lane
Since its introduction, pg_get_expr() has intended to silently return NULL if called with an invalid relation OID, as can happen when scanning the catalogs concurrently with relation drops. However, there is a race condition: we check validity of the OID at the start, but it could get dropped just afterward, leading to failures. This is the cause of some intermittent instability we're seeing in a proposed new test case, and presumably it's a hazard in the field as well. We can fix this by AccessShareLock-ing the target relation for the duration of pg_get_expr(). Since we don't require any permissions on the target relation, this is semantically a bit undesirable. But it turns out that the set_relation_column_names() subroutine already takes a transient AccessShareLock on that relation, and has done since commit 2ffa740be in 2012. Given the lack of complaints about that, it seems like there should be no harm in holding the lock a bit longer. Back-patch to all supported branches. Discussion: https://postgr.es/m/31ddcc01-a71b-4e8c-9948-01d1c47293ca@eisentraut.org
2024-02-09Fix wrong logic in TransactionIdInRecentPast()Alexander Korotkov
The TransactionIdInRecentPast() should return false for all the transactions older than TransamVariables->oldestClogXid. However, the function contains a bug in comparison FullTransactionId to TransactionID allowing full transactions between nextXid - 2^32 and oldestClogXid - 2^31. This commit fixes TransactionIdInRecentPast() by turning the oldestClogXid into FullTransactionId first, then performing the comparison. Backpatch to all supported versions. Reported-by: Egor Chindyaskin Bug: 18212 Discussion: https://postgr.es/m/18212-547307f8adf57262%40postgresql.org Author: Karina Litskevich Reviewed-by: Kyotaro Horiguchi Backpatch-through: 12
2024-02-02Translate ENOMEM to ERRCODE_OUT_OF_MEMORY in errcode_for_file_access().Tom Lane
Previously you got ERRCODE_INTERNAL_ERROR, which seems inappropriate, especially given that we're trying to avoid emitting that in reachable cases. Alexander Kuzmenkov Discussion: https://postgr.es/m/CALzhyqzgQph0BY8-hFRRGdHhF8CoqmmDHW9S=hMZ-HMzLxRqDQ@mail.gmail.com
2024-01-29Fix incompatibilities with libxml2 >= 2.12.0.Tom Lane
libxml2 changed the required signature of error handler callbacks to make the passed xmlError struct "const". This is causing build failures on buildfarm member caiman, and no doubt will start showing up in the field quite soon. Add a version check to adjust the declaration of xml_errorHandler() according to LIBXML_VERSION. 2.12.x also produces deprecation warnings for contrib/xml2/xpath.c's assignment to xmlLoadExtDtdDefaultValue. I see no good reason for that to still be there, seeing that we disabled external DTDs (at a lower level) years ago for security reasons. Let's just remove it. Back-patch to all supported branches, since they might all get built with newer libxml2 once it gets a bit more popular. (The back branches produce another deprecation warning about xpath.c's use of xmlSubstituteEntitiesDefault(). We ought to consider whether to back-patch all or part of commit 65c5864d7 to silence that. It's less urgent though, since it won't break the buildfarm.) Discussion: https://postgr.es/m/1389505.1706382262@sss.pgh.pa.us
2024-01-26Detect Julian-date overflow in timestamp[tz]_pl_interval.Tom Lane
We perform addition of the days field of an interval via arithmetic on the Julian-date representation of the timestamp's date. This step is subject to int32 overflow, and we also should not let the Julian date become very negative, for fear of weird results from j2date. (In the timestamptz case, allow a Julian date of -1 to pass, since it might convert back to zero after timezone rotation.) The additions of the months and microseconds fields could also overflow, of course. However, I believe we need no additional checks there; the existing range checks should catch such cases. The difficulty here is that j2date's magic modular arithmetic could produce something that looks like it's in-range. Per bug #18313 from Christian Maurer. This has been wrong for a long time, so back-patch to all supported branches. Discussion: https://postgr.es/m/18313-64d2c8952d81e84b@postgresql.org
2024-01-17Fix incorrect comment on how BackendStatusArray is indexedHeikki Linnakangas
The comment was copy-pasted from the call to ProcSignalInit() in AuxiliaryProcessMain(), which uses a similar scheme of having reserved slots for aux processes after MaxBackends slots for backends. However, ProcSignalInit() indexing starts from 1, whereas BackendStatusArray starts from 0. The code is correct, but the comment was wrong. Discussion: https://www.postgresql.org/message-id/f3ecd4cb-85ee-4e54-8278-5fabfb3a4ed0@iki.fi Backpatch-through: v14
2024-01-13Re-pgindent catcache.c after previous commit.Tom Lane
Discussion: https://postgr.es/m/1393953.1698353013@sss.pgh.pa.us Discussion: https://postgr.es/m/CAGjhLkOoBEC9mLsnB42d3CO1vcMx71MLSEuigeABbQ8oRdA6gw@mail.gmail.com
2024-01-13Cope with catcache entries becoming stale during detoasting.Tom Lane
We've long had a policy that any toasted fields in a catalog tuple should be pulled in-line before entering the tuple in a catalog cache. However, that requires access to the catalog's toast table, and we'll typically do AcceptInvalidationMessages while opening the toast table. So it's possible that the catalog tuple is outdated by the time we finish detoasting it. Since no cache entry exists yet, we can't mark the entry stale during AcceptInvalidationMessages, and instead we'll press forward and build an apparently-valid cache entry. The upshot is that we have a race condition whereby an out-of-date entry could be made in a backend's catalog cache, and persist there indefinitely causing indeterminate misbehavior. To fix, use the existing systable_recheck_tuple code to recheck whether the catalog tuple is still up-to-date after we finish detoasting it. If not, loop around and restart the process of searching the catalog and constructing cache entries from the top. The case is rare enough that this shouldn't create any meaningful performance penalty, even in the SearchCatCacheList case where we need to tear down and reconstruct the whole list. Indeed, the case is so rare that AFAICT it doesn't occur during our regression tests, and there doesn't seem to be any easy way to build a test that would exercise it reliably. To allow testing of the retry code paths, add logic (in USE_ASSERT_CHECKING builds only) that randomly pretends that the recheck failed about one time out of a thousand. This is enough to ensure that we'll pass through the retry paths during most regression test runs. By adding an extra level of looping, this commit creates a need to reindent most of SearchCatCacheMiss and SearchCatCacheList. I'll do that separately, to allow putting those changes in .git-blame-ignore-revs. Patch by me; thanks to Alexander Lakhin for having built a test case to prove the bug is real, and to Xiaoran Wang for review. Back-patch to all supported branches. Discussion: https://postgr.es/m/1393953.1698353013@sss.pgh.pa.us Discussion: https://postgr.es/m/CAGjhLkOoBEC9mLsnB42d3CO1vcMx71MLSEuigeABbQ8oRdA6gw@mail.gmail.com
2023-12-26Fix failure to verify PGC_[SU_]BACKEND GUCs in pg_file_settings view.Tom Lane
set_config_option() bails out early if it detects that the option to be set is PGC_BACKEND or PGC_SU_BACKEND class and we're reading the config file in a postmaster child; we don't want to apply any new value in such a case. That's fine as far as it goes, but it fails to consider the requirements of the pg_file_settings view: for that, we need to check validity of the value even though we have no intention to apply it. Because we didn't, even very silly values for affected GUCs would be reported as valid by the view. There are only half a dozen such GUCs, which perhaps explains why this got overlooked for so long. Fix by continuing when changeVal is false; this parallels the logic in some other early-exit paths. Also, the check added by commit 924bcf4f1 to prevent GUC changes in parallel workers seems a few bricks shy of a load: it's evidently assuming that ereport(elevel, ...) won't return. Make sure we bail out if it does. The lack of trouble reports suggests that this is only a latent bug, i.e. parallel workers don't actually reach here with elevel < ERROR. (Per the code coverage report, we never reach here at all in the regression suite.) But we clearly don't want to risk proceeding if that does happen. Per report from Rıdvan Korkmaz. These are ancient bugs, so back-patch to all supported branches. Discussion: https://postgr.es/m/2089235.1703617353@sss.pgh.pa.us
2023-11-18Guard against overflow in interval_mul() and interval_div().Dean Rasheed
Commits 146604ec43 and a898b409f6 added overflow checks to interval_mul(), but not to interval_div(), which contains almost identical code, and so is susceptible to the same kinds of overflows. In addition, those checks did not catch all possible overflow conditions. Add additional checks to the "cascade down" code in interval_mul(), and copy all the overflow checks over to the corresponding code in interval_div(), so that they both generate "interval out of range" errors, rather than returning bogus results. Given that these errors are relatively easy to hit, back-patch to all supported branches. Per bug #18200 from Alexander Lakhin, and subsequent investigation. Discussion: https://postgr.es/m/18200-5ea288c7b2d504b1%40postgresql.org
2023-11-10Ensure we use the correct spelling of "ensure"David Rowley
We seem to have accidentally used "insure" in a few places. Correct that. Author: Peter Smith Discussion: https://postgr.es/m/CAHut+Pv0biqrhA3pMhu40aDsj343mTsD75khKnHsLqR8P04f=Q@mail.gmail.com Backpatch-through: 12, oldest supported version
2023-11-06Detect integer overflow while computing new array dimensions.Tom Lane
array_set_element() and related functions allow an array to be enlarged by assigning to subscripts outside the current array bounds. While these places were careful to check that the new bounds are allowable, they neglected to consider the risk of integer overflow in computing the new bounds. In edge cases, we could compute new bounds that are invalid but get past the subsequent checks, allowing bad things to happen. Memory stomps that are potentially exploitable for arbitrary code execution are possible, and so is disclosure of server memory. To fix, perform the hazardous computations using overflow-detecting arithmetic routines, which fortunately exist in all still-supported branches. The test cases added for this generate (after patching) errors that mention the value of MaxArraySize, which is platform-dependent. Rather than introduce multiple expected-files, use psql's VERBOSITY parameter to suppress the printing of the message text. v11 psql lacks that parameter, so omit the tests in that branch. Our thanks to Pedro Gallegos for reporting this problem. Security: CVE-2023-5869
2023-11-06Set GUC "is_superuser" in all processes that set AuthenticatedUserId.Noah Misch
It was always false in single-user mode, in autovacuum workers, and in background workers. This had no specifically-identified security consequences, but non-core code or future work might make it security-relevant. Back-patch to v11 (all supported versions). Jelte Fennema-Nio. Reported by Jelte Fennema-Nio.
2023-11-02Be more wary about NULL values for GUC string variables.Tom Lane
get_explain_guc_options() crashed if a string GUC marked GUC_EXPLAIN has a NULL boot_val. Nosing around found a couple of other places that seemed insufficiently cautious about NULL string values, although those are likely unreachable in practice. Add some commentary defining the expectations for NULL values of string variables, in hopes of forestalling future additions of more such bugs. Xing Guo, Aleksander Alekseev, Tom Lane Discussion: https://postgr.es/m/CACpMh+AyDx5YUpPaAgzVwC1d8zfOL4JoD-uyFDnNSa1z0EsDQQ@mail.gmail.com
2023-10-31doc: 1-byte varlena headers can be used for user PLAIN storageBruce Momjian
This also updates some C comments. Reported-by: suchithjn22@gmail.com Discussion: https://postgr.es/m/167336599095.2667301.15497893107226841625@wrigleys.postgresql.org Author: Laurenz Albe (doc patch) Backpatch-through: 11
2023-10-20Dodge a compiler bug affecting timetz_zone/timetz_izone.Tom Lane
This avoids a compiler bug occurring in AIX's xlc, even in pretty late-model revisions. Buildfarm testing has now confirmed that only 64-bit xlc is affected. Although we are contemplating dropping support for xlc in v17, it's still supported in the back branches, so we need this fix. Back-patch of code changes from HEAD commit 19fa97731. (The test cases were already back-patched, in 4a427b82c et al.) Discussion: https://postgr.es/m/CA+hUKGK=DOC+hE-62FKfZy=Ybt5uLkrg3zCZD-jFykM-iPn8yw@mail.gmail.com
2023-10-17Avoid calling proc_exit() in processes forked by system().Nathan Bossart
The SIGTERM handler for the startup process immediately calls proc_exit() for the duration of the restore_command, i.e., a call to system(). This system() call forks a new process to execute the shell command, and this child process inherits the parent's signal handlers. If both the parent and child processes receive SIGTERM, both will attempt to call proc_exit(). This can end badly. For example, both processes will try to remove themselves from the PGPROC shared array. To fix this problem, this commit adds a check in StartupProcShutdownHandler() to see whether MyProcPid == getpid(). If they match, this is the parent process, and we can proc_exit() like before. If they do not match, this is a child process, and we just emit a message to STDERR (in a signal safe manner) and _exit(), thereby skipping any problematic exit callbacks. This commit also adds checks in proc_exit(), ProcKill(), and AuxiliaryProcKill() that verify they are not being called within such child processes. Suggested-by: Andres Freund Reviewed-by: Thomas Munro, Andres Freund Discussion: https://postgr.es/m/Y9nGDSgIm83FHcad%40paquier.xyz Discussion: https://postgr.es/m/20230223231503.GA743455%40nathanxps13 Backpatch-through: 11
2023-10-16Acquire ControlFileLock in relevant SQL functions.Thomas Munro
Commit dc7d70ea added functions that read the control file, but didn't acquire ControlFileLock. With unlucky timing, file systems that have weak interlocking like ext4 and ntfs could expose partially overwritten contents, and the checksum would fail. Back-patch to all supported releases. Reviewed-by: David Steele <david@pgmasters.net> Reviewed-by: Anton A. Melnikov <aamelnikov@inbox.ru> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/20221123014224.xisi44byq3cf5psi%40awork3.anarazel.de
2023-10-14Dissociate btequalimage() from interval_ops, ending its deduplication.Noah Misch
Under interval_ops, some equal values are distinguishable. One such pair is '24:00:00' and '1 day'. With that being so, btequalimage() breaches the documented contract for the "equalimage" btree support function. This can cause incorrect results from index-only scans. Users should REINDEX any btree indexes having interval-type columns. After updating, pg_amcheck will report an error for almost all such indexes. This fix makes interval_ops simply omit the support function, like numeric_ops does. Back-pack to v13, where btequalimage() first appeared. In back branches, for the benefit of old catalog content, btequalimage() code will return false for type "interval". Going forward, back-branch initdb will include the catalog change. Reviewed by Peter Geoghegan. Discussion: https://postgr.es/m/20231011013317.22.nmisch@google.com
2023-10-03Avoid memory size overflow when allocating backend activity bufferMichael Paquier
The code in charge of copying the contents of PgBackendStatus to local memory could fail on memory allocation because of an overflow on the amount of memory to use. The overflow can happen when combining a high value track_activity_query_size (max at 1MB) with a large max_connections, when both multiplied get higher than INT32_MAX as both parameters treated as signed integers. This could for example trigger with the following functions, all calling pgstat_read_current_status(): - pg_stat_get_backend_subxact() - pg_stat_get_backend_idset() - pg_stat_get_progress_info() - pg_stat_get_activity() - pg_stat_get_db_numbackends() The change to use MemoryContextAllocHuge() has been introduced in 8d0ddccec636, so backpatch down to 12. Author: Jakub Wartak Discussion: https://postgr.es/m/CAKZiRmw8QSNVw2qNK-dznsatQqz+9DkCquxP0GHbbv1jMkGHMA@mail.gmail.com Backpatch-through: 12
2023-10-01Fix datalen calculation in tsvectorrecv().Tom Lane
After receiving position data for a lexeme, tsvectorrecv() advanced its "datalen" value by (npos+1)*sizeof(WordEntry) where the correct calculation is (npos+1)*sizeof(WordEntryPos). This accidentally failed to render the constructed tsvector invalid, but it did result in leaving some wasted space approximately equal to the space consumed by the position data. That could have several bad effects: * Disk space is wasted if the received tsvector is stored into a table as-is. * A legal tsvector could get rejected with "maximum total lexeme length exceeded" if the extra space pushes it over the MAXSTRPOS limit. * In edge cases, the finished tsvector could be assigned a length larger than the allocated size of its palloc chunk, conceivably leading to SIGSEGV when the tsvector gets copied somewhere else. The odds of a field failure of this sort seem low, though valgrind testing could probably have found this. While we're here, let's express the calculation as "sizeof(uint16) + npos * sizeof(WordEntryPos)" to avoid the type pun implicit in the "npos + 1" formulation. It's not wrong given that WordEntryPos had better be 2 bytes to avoid padding problems, but it seems clearer this way. Report and patch by Denis Erokhin. Back-patch to all supported versions. Discussion: https://postgr.es/m/009801d9f2d9$f29730c0$d7c59240$@datagile.ru
2023-09-18Don't crash if cursor_to_xmlschema is used on a non-data-returning Portal.Tom Lane
cursor_to_xmlschema() assumed that any Portal must have a tupDesc, which is not so. Add a defensive check. It's plausible that this mistake occurred because of the rather poorly chosen name of the lookup function SPI_cursor_find(), which in such cases is returning something that isn't very much like a cursor. Add some documentation to try to forestall future errors of the same ilk. Report and patch by Boyu Yang (docs changes by me). Back-patch to all supported branches. Discussion: https://postgr.es/m/dd343010-c637-434c-a8cb-418f53bda3b8.yangboyu.yby@alibaba-inc.com
2023-09-15Track nesting depth correctly when drilling down into RECORD Vars.Tom Lane
expandRecordVariable() failed to adjust the parse nesting structure correctly when recursing to inspect an outer-level Var. This could result in assertion failures or core dumps in corner cases. Likewise, get_name_for_var_field() failed to adjust the deparse namespace stack correctly when recursing to inspect an outer-level Var. In this case the likely result was a "bogus varno" error while deparsing a view. Per bug #18077 from Jingzhou Fu. Back-patch to all supported branches. Richard Guo, with some adjustments by me Discussion: https://postgr.es/m/18077-b9db97c6e0ab45d8@postgresql.org
2023-09-14Revert "Improve error message on snapshot import in snapmgr.c"Michael Paquier
This reverts commit a0d87bcd9b57, following a remark from Andres Frend that the new error can be triggered with an incorrect SET TRANSACTION SNAPSHOT command without being really helpful for the user as it uses the internal file name. Discussion: https://postgr.es/m/20230914020724.hlks7vunitvtbbz4@awork3.anarazel.de Backpatch-through: 11
2023-09-14Improve error message on snapshot import in snapmgr.cMichael Paquier
When a snapshot file fails to be read in ImportSnapshot(), it would issue an ERROR as "invalid snapshot identifier" when opening a stream for it in read-only mode. This error message is reworded to be the same as all the other messages used in this case on failure, which is useful when debugging this area. Thinko introduced by bb446b689b66 where snapshot imports have been added. A backpatch down to 11 is done as this can improve any work related to snapshot imports in older branches. Author: Bharath Rupireddy Reviewed-by: Daniel Gustafsson Discussion: https://postgr.es/m/CALj2ACWmr=3KdxDkm8h7Zn1XxBoF6hdzq8WQyMn2y1OL5RYFrg@mail.gmail.com Backpatch-through: 11
2023-09-13Fix exception safety bug in typcache.c.Thomas Munro
If an out-of-memory error was thrown at an unfortunate time, ensure_record_cache_typmod_slot_exists() could leak memory and leave behind a global state that produced an infinite loop on the next call. Fix by merging RecordCacheArray and RecordIdentifierArray into a single array. With only one allocation or re-allocation, there is no intermediate state. Back-patch to all supported releases. Reported-by: "James Pang (chaolpan)" <chaolpan@cisco.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/PH0PR11MB519113E738814BDDA702EDADD6EFA%40PH0PR11MB5191.namprd11.prod.outlook.com
2023-09-04Fix out-of-bound read in gtsvector_picksplit()Michael Paquier
This could lead to an imprecise choice when splitting an index page of a GiST index on a tsvector, deciding which entries should remain on the old page and which entries should move to a new page. This is wrong since tsearch2 has been moved into core with commit 140d4ebcb46e, so backpatch all the way down. This error has been spotted by valgrind. Author: Alexander Lakhin Discussion: https://postgr.es/m/17950-6c80a8d2b94ec695@postgresql.org Backpatch-through: 11
2023-08-30Avoid possible overflow with ltsGetFreeBlock() in logtape.cMichael Paquier
nFreeBlocks, defined as a long, stores the number of free blocks in a logical tape. ltsGetFreeBlock() has been using an int to store the value of nFreeBlocks, which could lead to overflows on platforms where long and int are not the same size (in short everything except Windows where long is 4 bytes). The problematic intermediate variable is switched to be a long instead of an int. Issue introduced by c02fdc9223015, so backpatch down to 13. Author: Ranier vilela Reviewed-by: Peter Geoghegan, David Rowley Discussion: https://postgr.es/m/CAEudQApLDWCBR_xmwNjGBrDo+f+S4E87x3s7-+hoaKqYdtC4JQ@mail.gmail.com Backpatch-through: 13