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* Check return values of sensitive system library calls.Noah Misch2015-05-18
| | | | | | | | | | | | | | | | | | | | | | PostgreSQL already checked the vast majority of these, missing this handful that nearly cannot fail. If putenv() failed with ENOMEM in pg_GSS_recvauth(), authentication would proceed with the wrong keytab file. If strftime() returned zero in cache_locale_time(), using the unspecified buffer contents could lead to information exposure or a crash. Back-patch to 9.0 (all supported versions). Other unchecked calls to these functions, especially those in frontend code, pose negligible security concern. This patch does not address them. Nonetheless, it is always better to check return values whose specification provides for indicating an error. In passing, fix an off-by-one error in strftime_win32()'s invocation of WideCharToMultiByte(). Upon retrieving a value of exactly MAX_L10N_DATA bytes, strftime_win32() would overrun the caller's buffer by one byte. MAX_L10N_DATA is chosen to exceed the length of every possible value, so the vulnerable scenario probably does not arise. Security: CVE-2015-3166
* Remove spurious semicolons.Heikki Linnakangas2015-03-31
| | | | Petr Jelinek
* Fix dumping of views that are just VALUES(...) but have column aliases.Tom Lane2015-02-25
| | | | | | | | | | | | | | | The "simple" path for printing VALUES clauses doesn't work if we need to attach nondefault column aliases, because there's noplace to do that in the minimal VALUES() syntax. So modify get_simple_values_rte() to detect nondefault aliases and treat that as a non-simple case. This further exposes that the "non-simple" path never actually worked; it didn't produce valid syntax. Fix that too. Per bug #12789 from Curtis McEnroe, and analysis by Andrew Gierth. Back-patch to all supported branches. Before 9.3, this also requires back-patching the part of commit 092d7ded29f36b0539046b23b81b9f0bf2d637f1 that created get_simple_values_rte() to begin with; inserting the extra test into the old factorization of that logic would've been too messy.
* to_char(): prevent writing beyond the allocated bufferBruce Momjian2015-02-02
| | | | | | | | | | Previously very long localized month and weekday strings could overflow the allocated buffers, causing a server crash. Reported and patch reviewed by Noah Misch. Backpatch to all supported versions. Security: CVE-2015-0241
* to_char(): prevent accesses beyond the allocated bufferBruce Momjian2015-02-02
| | | | | | | | | | Previously very long field masks for floats could access memory beyond the existing buffer allocated to hold the result. Reported by Andres Freund and Peter Geoghegan. Backpatch to all supported versions. Security: CVE-2015-0241
* Fix column-privilege leak in error-message pathsStephen Frost2015-01-28
| | | | | | | | | | | | | | | | | | | | | While building error messages to return to the user, BuildIndexValueDescription and ri_ReportViolation would happily include the entire key or entire row in the result returned to the user, even if the user didn't have access to view all of the columns being included. Instead, include only those columns which the user is providing or which the user has select rights on. If the user does not have any rights to view the table or any of the columns involved then no detail is provided and a NULL value is returned from BuildIndexValueDescription. Note that, for key cases, the user must have access to all of the columns for the key to be shown; a partial key will not be returned. Back-patch all the way, as column-level privileges are now in all supported versions. This has been assigned CVE-2014-8161, but since the issue and the patch have already been publicized on pgsql-hackers, there's no point in trying to hide this commit.
* Fix NUMERIC field access macros to treat NaNs consistently.Tom Lane2015-01-27
| | | | | | | | | | | | | | | | Commit 145343534c153d1e6c3cff1fa1855787684d9a38 arranged to store numeric NaN values as short-header numerics, but the field access macros did not get the memo: they thought only "SHORT" numerics have short headers. Most of the time this makes no difference because we don't access the weight or dscale of a NaN; but numeric_send does that. As pointed out by Andrew Gierth, this led to fetching uninitialized bytes. AFAICS this could not have any worse consequences than that; in particular, an unaligned stored numeric would have been detoasted by PG_GETARG_NUMERIC, so that there's no risk of a fetch off the end of memory. Still, the code is wrong on its own terms, and it's not hard to foresee future changes that might expose us to real risks. So back-patch to all affected branches.
* Fix namespace handling in xpath functionPeter Eisentraut2015-01-17
| | | | | | | | | | Previously, the xml value resulting from an xpath query would not have namespace declarations if the namespace declarations were attached to an ancestor element in the input xml value. That means the output value was not correct XML. Fix that by running the result value through xmlCopyNode(), which produces the correct namespace declarations. Author: Ali Akbar <the.apaan@gmail.com>
* Backpatch variable renaming in formatting.cBruce Momjian2014-12-29
| | | | | | | Backpatch a9c22d1480aa8e6d97a000292d05ef2b31bbde4e to make future backpatching easier. Backpatch through 9.0
* Guard against bad "dscale" values in numeric_recv().Tom Lane2014-12-01
| | | | | | | | | | | | | | | | | | | | | | | | We were not checking to see if the supplied dscale was valid for the given digit array when receiving binary-format numeric values. While dscale can validly be more than the number of nonzero fractional digits, it shouldn't be less; that case causes fractional digits to be hidden on display even though they're there and participate in arithmetic. Bug #12053 from Tommaso Sala indicates that there's at least one broken client library out there that sometimes supplies an incorrect dscale value, leading to strange behavior. This suggests that simply throwing an error might not be the best response; it would lead to failures in applications that might seem to be working fine today. What seems the least risky fix is to truncate away any digits that would be hidden by dscale. This preserves the existing behavior in terms of what will be printed for the transmitted value, while preventing subsequent arithmetic from producing results inconsistent with that. In passing, throw a specific error for the case of dscale being outside the range that will fit into a numeric's header. Before you got "value overflows numeric format", which is a bit misleading. Back-patch to all supported branches.
* Fix two bugs in tsquery @> operator.Heikki Linnakangas2014-10-27
| | | | | | | | | | | | | 1. The comparison for matching terms used only the CRC to decide if there's a match. Two different terms with the same CRC gave a match. 2. It assumed that if the second operand has more terms than the first, it's never a match. That assumption is bogus, because there can be duplicate terms in either operand. Rewrite the implementation in a way that doesn't have those bugs. Backpatch to all supported versions.
* Support timezone abbreviations that sometimes change.Tom Lane2014-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up to now, PG has assumed that any given timezone abbreviation (such as "EDT") represents a constant GMT offset in the usage of any particular region; we had a way to configure what that offset was, but not for it to be changeable over time. But, as with most things horological, this view of the world is too simplistic: there are numerous regions that have at one time or another switched to a different GMT offset but kept using the same timezone abbreviation. Almost the entire Russian Federation did that a few years ago, and later this month they're going to do it again. And there are similar examples all over the world. To cope with this, invent the notion of a "dynamic timezone abbreviation", which is one that is referenced to a particular underlying timezone (as defined in the IANA timezone database) and means whatever it currently means in that zone. For zones that use or have used daylight-savings time, the standard and DST abbreviations continue to have the property that you can specify standard or DST time and get that time offset whether or not DST was theoretically in effect at the time. However, the abbreviations mean what they meant at the time in question (or most recently before that time) rather than being absolutely fixed. The standard abbreviation-list files have been changed to use this behavior for abbreviations that have actually varied in meaning since 1970. The old simple-numeric definitions are kept for abbreviations that have not changed, since they are a bit faster to resolve. While this is clearly a new feature, it seems necessary to back-patch it into all active branches, because otherwise use of Russian zone abbreviations is going to become even more problematic than it already was. This change supersedes the changes in commit 513d06ded et al to modify the fixed meanings of the Russian abbreviations; since we've not shipped that yet, this will avoid an undesirably incompatible (not to mention incorrect) change in behavior for timestamps between 2011 and 2014. This patch makes some cosmetic changes in ecpglib to keep its usage of datetime lookup tables as similar as possible to the backend code, but doesn't do anything about the increasingly obsolete set of timezone abbreviation definitions that are hard-wired into ecpglib. Whatever we do about that will likely not be appropriate material for back-patching. Also, a potential free() of a garbage pointer after an out-of-memory failure in ecpglib has been fixed. This patch also fixes pre-existing bugs in DetermineTimeZoneOffset() that caused it to produce unexpected results near a timezone transition, if both the "before" and "after" states are marked as standard time. We'd only ever thought about or tested transitions between standard and DST time, but that's not what's happening when a zone simply redefines their base GMT offset. In passing, update the SGML documentation to refer to the Olson/zoneinfo/ zic timezone database as the "IANA" database, since it's now being maintained under the auspices of IANA.
* Fix power_var_int() for large integer exponents.Tom Lane2014-09-11
| | | | | | | | | | | | | | | | | | | The code for raising a NUMERIC value to an integer power wasn't very careful about large powers. It got an outright wrong answer for an exponent of INT_MIN, due to failure to consider overflow of the Abs(exp) operation; which is fixable by using an unsigned rather than signed exponent value after that point. Also, even though the number of iterations of the power-computation loop is pretty limited, it's easy for the repeated squarings to result in ridiculously enormous intermediate values, which can take unreasonable amounts of time/memory to process, or even overflow the internal "weight" field and so produce a wrong answer. We can forestall misbehaviors of that sort by bailing out as soon as the weight value exceeds what will fit in int16, since then the final answer must overflow (if exp > 0) or underflow (if exp < 0) the packed numeric format. Per off-list report from Pavel Stehule. Back-patch to all supported branches.
* Handle duplicate XIDs in txid_snapshot.Heikki Linnakangas2014-05-15
| | | | | | | | | | The proc array can contain duplicate XIDs, when a transaction is just being prepared for two-phase commit. To cope, remove any duplicates in txid_current_snapshot(). Also ignore duplicates in the input functions, so that if e.g. you have an old pg_dump file that already contains duplicates, it will be accepted. Report and fix by Jan Wieck. Backpatch to all supported versions.
* Remove tabs after spaces in C commentsBruce Momjian2014-05-06
| | | | | | | | | This was not changed in HEAD, but will be done later as part of a pgindent run. Future pgindent runs will also do this. Report by Tom Lane Backpatch through all supported branches, but not HEAD
* Fix failure to detoast fields in composite elements of structured types.Tom Lane2014-05-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we have an array of records stored on disk, the individual record fields cannot contain out-of-line TOAST pointers: the tuptoaster.c mechanisms are only prepared to deal with TOAST pointers appearing in top-level fields of a stored row. The same applies for ranges over composite types, nested composites, etc. However, the existing code only took care of expanding sub-field TOAST pointers for the case of nested composites, not for other structured types containing composites. For example, given a command such as UPDATE tab SET arraycol = ARRAY[(ROW(x,42)::mycompositetype] ... where x is a direct reference to a field of an on-disk tuple, if that field is long enough to be toasted out-of-line then the TOAST pointer would be inserted as-is into the array column. If the source record for x is later deleted, the array field value would become a dangling pointer, leading to errors along the line of "missing chunk number 0 for toast value ..." when the value is referenced. A reproducible test case for this was provided by Jan Pecek, but it seems likely that some of the "missing chunk number" reports we've heard in the past were caused by similar issues. Code-wise, the problem is that PG_DETOAST_DATUM() is not adequate to produce a self-contained Datum value if the Datum is of composite type. Seen in this light, the problem is not just confined to arrays and ranges, but could also affect some other places where detoasting is done in that way, for example form_index_tuple(). I tried teaching the array code to apply toast_flatten_tuple_attribute() along with PG_DETOAST_DATUM() when the array element type is composite, but this was messy and imposed extra cache lookup costs whether or not any TOAST pointers were present, indeed sometimes when the array element type isn't even composite (since sometimes it takes a typcache lookup to find that out). The idea of extending that approach to all the places that currently use PG_DETOAST_DATUM() wasn't attractive at all. This patch instead solves the problem by decreeing that composite Datum values must not contain any out-of-line TOAST pointers in the first place; that is, we expand out-of-line fields at the point of constructing a composite Datum, not at the point where we're about to insert it into a larger tuple. This rule is applied only to true composite Datums, not to tuples that are being passed around the system as tuples, so it's not as invasive as it might sound at first. With this approach, the amount of code that has to be touched for a full solution is greatly reduced, and added cache lookup costs are avoided except when there actually is a TOAST pointer that needs to be inlined. The main drawback of this approach is that we might sometimes dereference a TOAST pointer that will never actually be used by the query, imposing a rather large cost that wasn't there before. On the other side of the coin, if the field value is used multiple times then we'll come out ahead by avoiding repeat detoastings. Experimentation suggests that common SQL coding patterns are unaffected either way, though. Applications that are very negatively affected could be advised to modify their code to not fetch columns they won't be using. In future, we might consider reverting this solution in favor of detoasting only at the point where data is about to be stored to disk, using some method that can drill down into multiple levels of nested structured types. That will require defining new APIs for structured types, though, so it doesn't seem feasible as a back-patchable fix. Note that this patch changes HeapTupleGetDatum() from a macro to a function call; this means that any third-party code using that macro will not get protection against creating TOAST-pointer-containing Datums until it's recompiled. The same applies to any uses of PG_RETURN_HEAPTUPLEHEADER(). It seems likely that this is not a big problem in practice: most of the tuple-returning functions in core and contrib produce outputs that could not possibly be toasted anyway, and the same probably holds for third-party extensions. This bug has existed since TOAST was invented, so back-patch to all supported branches.
* Check for interrupts and stack overflow during rule/view dumps.Tom Lane2014-04-30
| | | | | | | | | Since ruleutils.c recurses, it could be driven to stack overflow by deeply nested constructs. Very large queries might also take long enough to deparse that a check for interrupts seems like a good idea. Stick appropriate tests into a couple of key places. Noted by Greg Stark. Back-patch to all supported branches.
* Fix bugs in manipulation of PgBackendStatus.st_clienthostname.Tom Lane2014-04-01
| | | | | | | | | | Initialization of this field was not being done according to the st_changecount protocol (it has to be done within the changecount increment range, not outside). And the test to see if the value should be reported as null was wrong. Noted while perusing uses of Port.remote_hostname. This was wrong from the introduction of this code (commit 4a25bc145), so back-patch to 9.1.
* Avoid memcpy() with same source and destination address.Heikki Linnakangas2014-03-07
| | | | | | | The behavior of that is undefined, although unlikely to lead to problems in practice. Found by running regression tests with Valgrind.
* Avoid getting more than AccessShareLock when deparsing a query.Tom Lane2014-03-06
| | | | | | | | | | | | | | | | | | | | In make_ruledef and get_query_def, we have long used AcquireRewriteLocks to ensure that the querytree we are about to deparse is up-to-date and the schemas of the underlying relations aren't changing. Howwever, that function thinks the query is about to be executed, so it acquires locks that are stronger than necessary for the purpose of deparsing. Thus for example, if pg_dump asks to deparse a rule that includes "INSERT INTO t", we'd acquire RowExclusiveLock on t. That results in interference with concurrent transactions that might for example ask for ShareLock on t. Since pg_dump is documented as being purely read-only, this is unexpected. (Worse, it used to actually be read-only; this behavior dates back only to 8.1, cf commit ba4200246.) Fix this by adding a parameter to AcquireRewriteLocks to tell it whether we want the "real" execution locks or only AccessShareLock. Report, diagnosis, and patch by Dean Rasheed. Back-patch to all supported branches.
* Allow regex operations to be terminated early by query cancel requests.Tom Lane2014-03-01
| | | | | | | | | | | | | | | | | | | | | | | | | The regex code didn't have any provision for query cancel; which is unsurprising given its non-Postgres origin, but still problematic since some operations can take a long time. Introduce a callback function to check for a pending query cancel or session termination request, and call it in a couple of strategic spots where we can make the regex code exit with an error indicator. If we ever actually split out the regex code as a standalone library, some additional work will be needed to let the cancel callback function be specified externally to the library. But that's straightforward (certainly so by comparison to putting the locale-dependent character classification logic on a similar arms-length basis), and there seems no need to do it right now. A bigger issue is that there may be more places than these two where we need to check for cancels. We can always add more checks later, now that the infrastructure is in place. Since there are known examples of not-terribly-long regexes that can lock up a backend for a long time, back-patch to all supported branches. I have hopes of fixing the known performance problems later, but adding query cancel ability seems like a good idea even if they were all fixed.
* Use SnapshotDirty rather than an active snapshot to probe index endpoints.Tom Lane2014-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If there are lots of uncommitted tuples at the end of the index range, get_actual_variable_range() ends up fetching each one and doing an MVCC visibility check on it, until it finally hits a visible tuple. This is bad enough in isolation, considering that we don't need an exact answer only an approximate one. But because the tuples are not yet committed, each visibility check does a TransactionIdIsInProgress() test, which involves scanning the ProcArray. When multiple sessions do this concurrently, the ensuing contention results in horrid performance loss. 20X overall throughput loss on not-too-complicated queries is easy to demonstrate in the back branches (though someone's made it noticeably less bad in HEAD). We can dodge the problem fairly effectively by using SnapshotDirty rather than a normal MVCC snapshot. This will cause the index probe to take uncommitted tuples as good, so that we incur only one tuple fetch and test even if there are many such tuples. The extent to which this degrades the estimate is debatable: it's possible the result is actually a more accurate prediction than before, if the endmost tuple has become committed by the time we actually execute the query being planned. In any case, it's not very likely that it makes the estimate a lot worse. SnapshotDirty will still reject tuples that are known committed dead, so we won't give bogus answers if an invalid outlier has been deleted but not yet vacuumed from the index. (Because btrees know how to mark such tuples dead in the index, we shouldn't have a big performance problem in the case that there are many of them at the end of the range.) This consideration motivates not using SnapshotAny, which was also considered as a fix. Note: the back branches were using SnapshotNow instead of an MVCC snapshot, but the problem and solution are the same. Per performance complaints from Bartlomiej Romanski, Josh Berkus, and others. Back-patch to 9.0, where the issue was introduced (by commit 40608e7f949fb7e4025c0ddd5be01939adc79eec).
* Prevent potential overruns of fixed-size buffers.Tom Lane2014-02-17
| | | | | | | | | | | | | | | | | | | | | | | Coverity identified a number of places in which it couldn't prove that a string being copied into a fixed-size buffer would fit. We believe that most, perhaps all of these are in fact safe, or are copying data that is coming from a trusted source so that any overrun is not really a security issue. Nonetheless it seems prudent to forestall any risk by using strlcpy() and similar functions. Fixes by Peter Eisentraut and Jozef Mlich based on Coverity reports. In addition, fix a potential null-pointer-dereference crash in contrib/chkpass. The crypt(3) function is defined to return NULL on failure, but chkpass.c didn't check for that before using the result. The main practical case in which this could be an issue is if libc is configured to refuse to execute unapproved hashing algorithms (e.g., "FIPS mode"). This ideally should've been a separate commit, but since it touches code adjacent to one of the buffer overrun changes, I included it in this commit to avoid last-minute merge issues. This issue was reported by Honza Horak. Security: CVE-2014-0065 for buffer overruns, CVE-2014-0066 for crypt()
* Predict integer overflow to avoid buffer overruns.Noah Misch2014-02-17
| | | | | | | | | | | | | | | | | Several functions, mostly type input functions, calculated an allocation size such that the calculation wrapped to a small positive value when arguments implied a sufficiently-large requirement. Writes past the end of the inadvertent small allocation followed shortly thereafter. Coverity identified the path_in() vulnerability; code inspection led to the rest. In passing, add check_stack_depth() to prevent stack overflow in related functions. Back-patch to 8.4 (all supported versions). The non-comment hstore changes touch code that did not exist in 8.4, so that part stops at 9.0. Noah Misch and Heikki Linnakangas, reviewed by Tom Lane. Security: CVE-2014-0064
* Shore up ADMIN OPTION restrictions.Noah Misch2014-02-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Granting a role without ADMIN OPTION is supposed to prevent the grantee from adding or removing members from the granted role. Issuing SET ROLE before the GRANT bypassed that, because the role itself had an implicit right to add or remove members. Plug that hole by recognizing that implicit right only when the session user matches the current role. Additionally, do not recognize it during a security-restricted operation or during execution of a SECURITY DEFINER function. The restriction on SECURITY DEFINER is not security-critical. However, it seems best for a user testing his own SECURITY DEFINER function to see the same behavior others will see. Back-patch to 8.4 (all supported versions). The SQL standards do not conflate roles and users as PostgreSQL does; only SQL roles have members, and only SQL users initiate sessions. An application using PostgreSQL users and roles as SQL users and roles will never attempt to grant membership in the role that is the session user, so the implicit right to add or remove members will never arise. The security impact was mostly that a role member could revoke access from others, contrary to the wishes of his own grantor. Unapproved role member additions are less notable, because the member can still largely achieve that by creating a view or a SECURITY DEFINER function. Reviewed by Andres Freund and Tom Lane. Reported, independently, by Jonas Sundman and Noah Misch. Security: CVE-2014-0060
* Fix misplaced right paren bugs in pgstatfuncs.c.Kevin Grittner2013-12-27
| | | | | | | | | | | | | | The bug would only show up if the C sockaddr structure contained zero in the first byte for a valid address; otherwise it would fail to fail, which is probably why it went unnoticed for so long. Patch submitted by Joel Jacobson after seeing an article by Andrey Karpov in which he reports finding this through static code analysis using PVS-Studio. While I was at it I moved a definition of a local variable referenced in the buggy code to a more local context. Backpatch to all supported branches.
* Avoid potential buffer overflow crashPeter Eisentraut2013-11-23
| | | | | | | | | | A pointer to a C string was treated as a pointer to a "name" datum and passed to SPI_execute_plan(). This pointer would then end up being passed through datumCopy(), which would try to copy the entire 64 bytes of name data, thus running past the end of the C string. Fix by converting the string to a proper name structure. Found by LLVM AddressSanitizer.
* Fix some odd behaviors when using a SQL-style simple GMT offset timezone.Tom Lane2013-11-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Formerly, when using a SQL-spec timezone setting with a fixed GMT offset (called a "brute force" timezone in the code), the session_timezone variable was not updated to match the nominal timezone; rather, all code was expected to ignore session_timezone if HasCTZSet was true. This is of course obviously fragile, though a search of the code finds only timeofday() failing to honor the rule. A bigger problem was that DetermineTimeZoneOffset() supposed that if its pg_tz parameter was pointer-equal to session_timezone, then HasCTZSet should override the parameter. This would cause datetime input containing an explicit zone name to be treated as referencing the brute-force zone instead, if the zone name happened to match the session timezone that had prevailed before installing the brute-force zone setting (as reported in bug #8572). The same malady could affect AT TIME ZONE operators. To fix, set up session_timezone so that it matches the brute-force zone specification, which we can do using the POSIX timezone definition syntax "<abbrev>offset", and get rid of the bogus lookaside check in DetermineTimeZoneOffset(). Aside from fixing the erroneous behavior in datetime parsing and AT TIME ZONE, this will cause the timeofday() function to print its result in the user-requested time zone rather than some previously-set zone. It might also affect results in third-party extensions, if there are any that make use of session_timezone without considering HasCTZSet, but in all cases the new behavior should be saner than before. Back-patch to all supported branches.
* Make sure float4in/float8in accept all standard spellings of "infinity".Tom Lane2013-08-03
| | | | | | | | | | | | | | | | The C99 and POSIX standards require strtod() to accept all these spellings (case-insensitively): "inf", "+inf", "-inf", "infinity", "+infinity", "-infinity". However, pre-C99 systems might accept only some or none of these, and apparently Windows still doesn't accept "inf". To avoid surprising cross-platform behavioral differences, manually check for each of these spellings if strtod() fails. We were previously handling just "infinity" and "-infinity" that way, but since C99 is most of the world now, it seems likely that applications are expecting all these spellings to work. Per bug #8355 from Basil Peace. It turns out this fix won't actually resolve his problem, because Python isn't being this careful; but that doesn't mean we shouldn't be.
* Fix regexp_matches() handling of zero-length matches.Tom Lane2013-07-31
| | | | | | | | | | | We'd find the same match twice if it was of zero length and not immediately adjacent to the previous match. replace_text_regexp() got similar cases right, so adjust this search logic to match that. Note that even though the regexp_split_to_xxx() functions share this code, they did not display equivalent misbehavior, because the second match would be considered degenerate and ignored. Jeevan Chalke, with some cosmetic changes by me.
* Fix booltestsel() for case where we have NULL stats but not MCV stats.Tom Lane2013-07-24
| | | | | | | | | | | | In a boolean column that contains mostly nulls, ANALYZE might not find enough non-null values to populate the most-common-values stats, but it would still create a pg_statistic entry with stanullfrac set. The logic in booltestsel() for this situation did the wrong thing for "col IS NOT TRUE" and "col IS NOT FALSE" tests, forgetting that null values would satisfy these tests (so that the true selectivity would be close to one, not close to zero). Per bug #8274. Fix by Andrew Gierth, some comment-smithing by me.
* Change post-rewriter representation of dropped columns in joinaliasvars.Tom Lane2013-07-23
| | | | | | | | | | | | | | | | | | | | | It's possible to drop a column from an input table of a JOIN clause in a view, if that column is nowhere actually referenced in the view. But it will still be there in the JOIN clause's joinaliasvars list. We used to replace such entries with NULL Const nodes, which is handy for generation of RowExpr expansion of a whole-row reference to the view. The trouble with that is that it can't be distinguished from the situation after subquery pull-up of a constant subquery output expression below the JOIN. Instead, replace such joinaliasvars with null pointers (empty expression trees), which can't be confused with pulled-up expressions. expandRTE() still emits the old convention, though, for convenience of RowExpr generation and to reduce the risk of breaking extension code. In HEAD and 9.3, this patch also fixes a problem with some new code in ruleutils.c that was failing to cope with implicitly-casted joinaliasvars entries, as per recent report from Feike Steenbergen. That oversight was because of an inadequate description of the data structure in parsenodes.h, which I've now corrected. There were some pre-existing oversights of the same ilk elsewhere, which I believe are now all fixed.
* Guard against input_rows == 0 in estimate_num_groups().Tom Lane2013-05-10
| | | | | | | | | | | | | | | This case doesn't normally happen, because the planner usually clamps all row estimates to at least one row; but I found that it can arise when dealing with relations excluded by constraints. Without a defense, estimate_num_groups() can return zero, which leads to divisions by zero inside the planner as well as assertion failures in the executor. An alternative fix would be to change set_dummy_rel_pathlist() to make the size estimate for a dummy relation 1 row instead of 0, but that seemed pretty ugly; and probably someday we'll want to drop the convention that the minimum rowcount estimate is 1 row. Back-patch to 8.4, as the problem can be demonstrated that far back.
* Fix to_char() to use ASCII-only case-folding rules where appropriate.Tom Lane2013-03-05
| | | | | | | | | | | | | | formatting.c used locale-dependent case folding rules in some code paths where the result isn't supposed to be locale-dependent, for example to_char(timestamp, 'DAY'). Since the source data is always just ASCII in these cases, that usually didn't matter ... but it does matter in Turkish locales, which have unusual treatment of "i" and "I". To confuse matters even more, the misbehavior was only visible in UTF8 encoding, because in single-byte encodings we used pg_toupper/pg_tolower which don't have locale-specific behavior for ASCII characters. Fix by providing intentionally ASCII-only case-folding functions and using these where appropriate. Per bug #7913 from Adnan Dursun. Back-patch to all active branches, since it's been like this for a long time.
* Fix overflow check in tm2timestamp (this time for sure).Tom Lane2013-03-04
| | | | | | I fixed this code back in commit 841b4a2d5, but didn't think carefully enough about the behavior near zero, which meant it improperly rejected 1999-12-31 24:00:00. Per report from Magnus Hagander.
* Prevent execution of enum_recv() from SQL.Tom Lane2013-02-04
| | | | | | | | | | | | | | | | | This function was misdeclared to take cstring when it should take internal. This at least allows crashing the server, and in principle an attacker might be able to use the function to examine the contents of server memory. The correct fix is to adjust the system catalog contents (and fix the regression tests that should have caught this but failed to). However, asking users to correct the catalog contents in existing installations is a pain, so as a band-aid fix for the back branches, install a check in enum_recv() to make it throw error if called with a cstring argument. We will later revert this in HEAD in favor of correcting the catalogs. Our thanks to Sumit Soni (via Secunia SVCRP) for reporting this issue. Security: CVE-2013-0255
* Reject out-of-range dates in to_date().Tom Lane2013-01-14
| | | | | | | | | Dates outside the supported range could be entered, but would not print reasonably, and operations such as conversion to timestamp wouldn't behave sanely either. Since this has the potential to result in undumpable table data, it seems worth back-patching. Hitoshi Harada
* Fix failure to ignore leftover temp tables after a server crash.Tom Lane2012-12-17
| | | | | | | | | | | | | | | | | | | During crash recovery, we remove disk files belonging to temporary tables, but the system catalog entries for such tables are intentionally not cleaned up right away. Instead, the first backend that uses a temp schema is expected to clean out any leftover objects therein. This approach requires that we be careful to ignore leftover temp tables (since any actual access attempt would fail), *even if their BackendId matches our session*, if we have not yet established use of the session's corresponding temp schema. That worked fine in the past, but was broken by commit debcec7dc31a992703911a9953e299c8d730c778 which incorrectly removed the rd_islocaltemp relcache flag. Put it back, and undo various changes that substituted tests like "rel->rd_backend == MyBackendId" for use of a state-aware flag. Per trouble report from Heikki Linnakangas. Back-patch to 9.1 where the erroneous change was made. In the back branches, be careful to add rd_islocaltemp in a spot in the struct that was alignment padding before, so as not to break existing add-on code.
* Improve handling of INT_MIN / -1 and related cases.Tom Lane2012-11-19
| | | | | | | | | | | | | | | Some platforms throw an exception for this division, rather than returning a necessarily-overflowed result. Since we were testing for overflow after the fact, an exception isn't nice. We can avoid the problem by treating division by -1 as negation. Add some regression tests so that we'll find out if any compilers try to optimize away the overflow check conditions. Back-patch of commit 1f7cb5c30983752ff8de833de30afcaee63536d0. Per discussion with Xi Wang, though this is different from the patch he submitted.
* Fix the int8 and int2 cases of (minimum possible integer) % (-1).Tom Lane2012-11-14
| | | | | | | | | | | | | | The correct answer for this (or any other case with arg2 = -1) is zero, but some machines throw a floating-point exception instead of behaving sanely. Commit f9ac414c35ea084ff70c564ab2c32adb06d5296f dealt with this in int4mod, but overlooked the fact that it also happens in int8mod (at least on my Linux x86_64 machine). Protect int2mod as well; it's not clear whether any machines fail there (mine does not) but since the test is so cheap it seems better safe than sorry. While at it, simplify the original guard in int4mod: we need only check for arg2 == -1, we don't need to check arg1 explicitly. Xi Wang, with some editing by me.
* Fix memory leaks in record_out() and record_send().Tom Lane2012-11-13
| | | | | | | | | | | | | | | | | | | | | record_out() leaks memory: it fails to free the strings returned by the per-column output functions, and also is careless about detoasted values. This results in a query-lifespan memory leakage when returning composite values to the client, because printtup() runs the output functions in the query-lifespan memory context. Fix it to handle these issues the same way printtup() does. Also fix a similar leakage in record_send(). (At some point we might want to try to run output functions in shorter-lived memory contexts, so that we don't need a zero-leakage policy for them. But that would be a significantly more invasive patch, which doesn't seem like material for back-patching.) In passing, use appendStringInfoCharMacro instead of appendStringInfoChar in the innermost data-copying loop of record_out, to try to shave a few cycles from this function's runtime. Per trouble report from Carlos Henrique Reimer. Back-patch to all supported versions.
* Fix ruleutils to print "INSERT INTO foo DEFAULT VALUES" correctly.Tom Lane2012-10-19
| | | | | Per bug #7615 from Marko Tiikkaja. Apparently nobody ever tried this case before ...
* Fix access past end of string in date parsing.Heikki Linnakangas2012-10-02
| | | | | | This affects date_in(), and a couple of other funcions that use DecodeDate(). Hitoshi Harada
* Make configure probe for mbstowcs_l as well as wcstombs_l.Tom Lane2012-08-31
| | | | | | | | | | | We previously supposed that any given platform would supply both or neither of these functions, so that one configure test would be sufficient. It now appears that at least on AIX this is not the case ... which is likely an AIX bug, but nonetheless we need to cope with it. So use separate tests. Per bug #6758; thanks to Andrew Hastie for doing the followup testing needed to confirm what was happening. Backpatch to 9.1, where we began using these functions.
* Fix cascading privilege revoke to notice when privileges are still held.Tom Lane2012-08-23
| | | | | | | | | | | | If we revoke a grant option from some role X, but X still holds the option via another grant, we should not recursively revoke the privilege from role(s) Y that X had granted it to. This was supposedly fixed as one aspect of commit 4b2dafcc0b1a579ef5daaa2728223006d1ff98e9, but I must not have tested it, because in fact that code never worked: it forgot to shift the grant-option bits back over when masking the bits being revoked. Per bug #6728 from Daniel German. Back-patch to all active branches, since this has been wrong since 8.0.
* Prevent access to external files/URLs via XML entity references.Tom Lane2012-08-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | xml_parse() would attempt to fetch external files or URLs as needed to resolve DTD and entity references in an XML value, thus allowing unprivileged database users to attempt to fetch data with the privileges of the database server. While the external data wouldn't get returned directly to the user, portions of it could be exposed in error messages if the data didn't parse as valid XML; and in any case the mere ability to check existence of a file might be useful to an attacker. The ideal solution to this would still allow fetching of references that are listed in the host system's XML catalogs, so that documents can be validated according to installed DTDs. However, doing that with the available libxml2 APIs appears complex and error-prone, so we're not going to risk it in a security patch that necessarily hasn't gotten wide review. So this patch merely shuts off all access, causing any external fetch to silently expand to an empty string. A future patch may improve this. In HEAD and 9.2, also suppress warnings about undefined entities, which would otherwise occur as a result of not loading referenced DTDs. Previous branches don't show such warnings anyway, due to different error handling arrangements. Credit to Noah Misch for first reporting the problem, and for much work towards a solution, though this simplistic approach was not his preference. Also thanks to Daniel Veillard for consultation. Security: CVE-2012-3489
* Fix bugs with parsing signed hh:mm and hh:mm:ss fields in interval input.Tom Lane2012-08-03
| | | | | | | | | | | | | | | | | | | | | | | DecodeInterval() failed to honor the "range" parameter (the special SQL syntax for indicating which fields appear in the literal string) if the time was signed. This seems inappropriate, so make it work like the not-signed case. The inconsistency was introduced in my commit f867339c0148381eb1d01f93ab5c79f9d10211de, which as noted in its log message was only really focused on making SQL-compliant literals work per spec. Including a sign here is not per spec, but if we're going to allow it then it's reasonable to expect it to work like the not-signed case. Also, remove bogus setting of tmask, which caused subsequent processing to think that what had been given was a timezone and not an hh:mm(:ss) field, thus confusing checks for redundant fields. This seems to be an aboriginal mistake in Lockhart's commit 2cf1642461536d0d8f3a1cf124ead0eac04eb760. Add regression test cases to illustrate the changed behaviors. Back-patch as far as 8.4, where support for spec-compliant interval literals was added. Range problem reported and diagnosed by Amit Kapila, tmask problem by me.
* Prevent corner-case core dump in rfree().Tom Lane2012-07-15
| | | | | | | | | | | | | rfree() failed to cope with the case that pg_regcomp() had initialized the regex_t struct but then failed to allocate any memory for re->re_guts (ie, the first malloc call in pg_regcomp() failed). It would try to touch the guts struct anyway, and thus dump core. This is a sufficiently narrow corner case that it's not surprising it's never been seen in the field; but still a bug is a bug, so patch all active branches. Noted while investigating whether we need to call pg_regfree after a failure return from pg_regcomp. Other than this bug, it turns out we don't, so adjust comments appropriately.
* Back-patch fix for extraction of fixed prefixes from regular expressions.Tom Lane2012-07-10
| | | | | | Back-patch of commits 628cbb50ba80c83917b07a7609ddec12cda172d0 and c6aae3042be5249e672b731ebeb21875b5343010. This has been broken since 7.3, so back-patch to all supported branches.
* Refactor pattern_fixed_prefix() to avoid dealing in incomplete patterns.Tom Lane2012-07-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, pattern_fixed_prefix() was defined to return whatever fixed prefix it could extract from the pattern, plus the "rest" of the pattern. That definition was sensible for LIKE patterns, but not so much for regexes, where reconstituting a valid pattern minus the prefix could be quite tricky (certainly the existing code wasn't doing that correctly). Since the only thing that callers ever did with the "rest" of the pattern was to pass it to like_selectivity() or regex_selectivity(), let's cut out the middle-man and just have pattern_fixed_prefix's subroutines do this directly. Then pattern_fixed_prefix can return a simple selectivity number, and the question of how to cope with partial patterns is removed from its API specification. While at it, adjust the API spec so that callers who don't actually care about the pattern's selectivity (which is a lot of them) can pass NULL for the selectivity pointer to skip doing the work of computing a selectivity estimate. This patch is only an API refactoring that doesn't actually change any processing, other than allowing a little bit of useless work to be skipped. However, it's necessary infrastructure for my upcoming fix to regex prefix extraction, because after that change there won't be any simple way to identify the "rest" of the regex, not even to the low level of fidelity needed by regex_selectivity. We can cope with that if regex_fixed_prefix and regex_selectivity communicate directly, but not if we have to work within the old API. Hence, back-patch to all active branches.