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* Fix ExecMakeTableFunctionResult to verify that all rows returned by a SRFTom Lane2010-08-26
| | | | | | | | | | | returning "record" actually do have the same rowtype. This is needed because the parser can't realistically enforce that they will all have the same typmod, as seen in a recent example from David Wheeler. Back-patch to 8.0, which is as far back as we have the notion of RECORD subtypes being distinguished by typmod. Wheeler's example depends on 8.4-and-up features, but I suspect there may be ways to provoke similar failures before 8.4.
* Fix potential failure when hashing the output of a subplan that producesTom Lane2010-07-28
| | | | | | | | | | | | | | | a pass-by-reference datatype with a nontrivial projection step. We were using the same memory context for the projection operation as for the temporary context used by the hashtable routines in execGrouping.c. However, the hashtable routines feel free to reset their temp context at any time, which'd lead to destroying input data that was still needed. Report and diagnosis by Tao Ma. Back-patch to 8.1, where the problem was introduced by the changes that allowed us to work with "virtual" tuples instead of materializing intermediate tuple values everywhere. The earlier code looks quite similar, but it doesn't suffer the problem because the data gets copied into another context as a result of having to materialize ExecProject's output tuple.
* Previous fix for temporary file management broke returning a set fromHeikki Linnakangas2009-12-29
| | | | | | | | | | | | | | PL/pgSQL function within an exception handler. Make sure we use the right resource owner when we create the tuplestore to hold returned tuples. Simplify tuplestore API so that the caller doesn't need to be in the right memory context when calling tuplestore_put* functions. tuplestore.c automatically switches to the memory context used when the tuplestore was created. Tuplesort was already modified like this earlier. This patch also removes the now useless MemoryContextSwitch calls from callers. Report by Aleksei on pgsql-bugs on Dec 22 2009. Backpatch to 8.1, like the previous patch that broke this.
* Prevent indirect security attacks via changing session-local state withinTom Lane2009-12-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | an allegedly immutable index function. It was previously recognized that we had to prevent such a function from executing SET/RESET ROLE/SESSION AUTHORIZATION, or it could trivially obtain the privileges of the session user. However, since there is in general no privilege checking for changes of session-local state, it is also possible for such a function to change settings in a way that might subvert later operations in the same session. Examples include changing search_path to cause an unexpected function to be called, or replacing an existing prepared statement with another one that will execute a function of the attacker's choosing. The present patch secures VACUUM, ANALYZE, and CREATE INDEX/REINDEX against these threats, which are the same places previously deemed to need protection against the SET ROLE issue. GUC changes are still allowed, since there are many useful cases for that, but we prevent security problems by forcing a rollback of any GUC change after completing the operation. Other cases are handled by throwing an error if any change is attempted; these include temp table creation, closing a cursor, and creating or deleting a prepared statement. (In 7.4, the infrastructure to roll back GUC changes doesn't exist, so we settle for rejecting changes of "search_path" in these contexts.) Original report and patch by Gurjeet Singh, additional analysis by Tom Lane. Security: CVE-2009-4136
* Make the overflow guards in ExecChooseHashTableSize be more protective.Tom Lane2009-10-30
| | | | | | | | | | | | | | | The original coding ensured nbuckets and nbatch didn't exceed INT_MAX, which while not insane on its own terms did nothing to protect subsequent code like "palloc(nbatch * sizeof(BufFile *))". Since enormous join size estimates might well be planner error rather than reality, it seems best to constrain the initial sizes to be not more than work_mem/sizeof(pointer), thus ensuring the allocated arrays don't exceed work_mem. We will allow nbatch to get bigger than that during subsequent ExecHashIncreaseNumBatches calls, but we should still guard against integer overflow in those palloc requests. Per bug #5145 from Bernt Marius Johnsen. Although the given test case only seems to fail back to 8.2, previous releases have variants of this issue, so patch all supported branches.
* Ensure that the contents of a holdable cursor don't depend on out-of-lineTom Lane2008-12-01
| | | | | | | | | | | toasted values, since those could get dropped once the cursor's transaction is over. Per bug #4553 from Andrew Gierth. Back-patch as far as 8.1. The bug actually exists back to 7.4 when holdable cursors were introduced, but this patch won't work before 8.1 without significant adjustments. Given the lack of field complaints, it doesn't seem worth the work (and risk of introducing new bugs) to try to make a patch for the older branches.
* Fix SPI_getvalue and SPI_getbinval to range-check the given attribute numberTom Lane2008-10-16
| | | | | | | | | | | | | | according to the TupleDesc's natts, not the number of physical columns in the tuple. The previous coding would do the wrong thing in cases where natts is different from the tuple's column count: either incorrectly report error when it should just treat the column as null, or actually crash due to indexing off the end of the TupleDesc's attribute array. (The second case is probably not possible in modern PG versions, due to more careful handling of inheritance cases than we once had. But it's still a clear lack of robustness here.) The incorrect error indication is ignored by all callers within the core PG distribution, so this bug has no symptoms visible within the core code, but it might well be an issue for add-on packages. So patch all the way back.
* Install checks in executor startup to ensure that the tuples produced by anTom Lane2008-08-08
| | | | | | | | | | | | INSERT or UPDATE will match the target table's current rowtype. In pre-8.3 releases inconsistency can arise with stale cached plans, as reported by Merlin Moncure. (We patched the equivalent hazard on the SELECT side in Feb 2007; I'm not sure why we thought there was no risk on the insertion side.) In 8.3 and HEAD this problem should be impossible due to plan cache invalidation management, but it seems prudent to make the check anyway. Back-patch as far as 8.0. 7.x versions lack ALTER COLUMN TYPE, so there seems no way to abuse a stale plan comparably.
* Do not allow Unique nodes to be scanned backwards. The code claimed that itTom Lane2008-08-05
| | | | | | | would work, but in fact it didn't return the same rows when moving backwards as when moving forwards. This would have no visible effect in a DISTINCT query (at least assuming the column datatypes use a strong definition of equality), but it gave entirely wrong answers for DISTINCT ON queries.
* Fix mis-calculation of extParam/allParam sets for plan nodes, as seen inTom Lane2008-07-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | bug #4290. The fundamental bug is that masking extParam by outer_params, as finalize_plan had been doing, caused us to lose the information that an initPlan depended on the output of a sibling initPlan. On reflection the best thing to do seemed to be not to try to adjust outer_params for this case but get rid of it entirely. The only thing it was really doing for us was to filter out param IDs associated with SubPlan nodes, and that can be done (with greater accuracy) while processing individual SubPlan nodes in finalize_primnode. This approach was vindicated by the discovery that the masking method was hiding a second bug: SS_finalize_plan failed to remove extParam bits for initPlan output params that were referenced in the main plan tree (it only got rid of those referenced by other initPlans). It's not clear that this caused any real problems, given the limited use of extParam by the executor, but it's certainly not what was intended. I originally thought that there was also a problem with needing to include indirect dependencies on external params in initPlans' param sets, but it turns out that the executor handles this correctly so long as the depended-on initPlan is earlier in the initPlans list than the one using its output. That seems a bit of a fragile assumption, but it is true at the moment, so I just documented it in some code comments rather than making what would be rather invasive changes to remove the assumption. Back-patch to 8.1. Previous versions don't have the case of initPlans referring to other initPlans' outputs, so while the existing logic is still questionable for them, there are not any known bugs to be fixed. So I'll refrain from changing them for now.
* Repair problems occurring when multiple RI updates have to be done to the sameTom Lane2007-08-15
| | | | | | | | | row within one query: we were firing check triggers before all the updates were done, leading to bogus failures. Fix by making the triggers queued by an RI update go at the end of the outer query's trigger event list, thereby effectively making the processing "breadth-first". This was indeed how it worked pre-8.0, so the bug does not occur in the 7.x branches. Per report from Pavel Stehule.
* Fix a gradual memory leak in ExecReScanAgg(). Because the aggregationNeil Conway2007-08-08
| | | | | | | | | | | | hash table is allocated in a child context of the agg node's memory context, MemoryContextReset() will reset but *not* delete the child context. Since ExecReScanAgg() proceeds to build a new hash table from scratch (in a new sub-context), this results in leaking the header for the previous memory context. Therefore, use MemoryContextResetAndDeleteChildren() instead. Credit: My colleague Sailesh Krishnamurthy at Truviso for isolating the cause of the leak.
* Fix performance problems in multi-batch hash joins by ensuring that we selectTom Lane2007-06-01
| | | | | | | | | | a well-randomized batch number even when given a poorly-randomized hash value. This is a bit inefficient but seems the only practical solution given the constraint that we can't change the hash functions in released branches. Per report from Joseph Shraibman. Applied to 8.1 and 8.2 only --- HEAD is getting a cleaner fix, and 8.0 and before use different coding that seems less vulnerable.
* Fix dynahash.c to suppress hash bucket splits while a hash_seq_search() scanTom Lane2007-04-26
| | | | | | | | | | | | | | | | | | | | | | | is in progress on the same hashtable. This seems the least invasive way to fix the recently-recognized problem that a split could cause the scan to visit entries twice or (with much lower probability) miss them entirely. The only field-reported problem caused by this is the "failed to re-find shared lock object" PANIC in COMMIT PREPARED reported by Michel Dorochevsky, which was caused by multiply visited entries. However, it seems certain that mdsync() is vulnerable to missing required fsync's due to missed entries, and I am fearful that RelationCacheInitializePhase2() might be at risk as well. Because of that and the generalized hazard presented by this bug, back-patch all the supported branches. Along the way, fix pg_prepared_statement() and pg_cursor() to not assume that the hashtables they are examining will stay static between calls. This is risky regardless of the newly noted dynahash problem, because hash_seq_search() has never promised to cope with deletion of table entries other than the just-returned one. There may be no bug here because the only supported way to call these functions is via ExecMakeTableFunctionResult() which will cycle them to completion before doing anything very interesting, but it seems best to get rid of the assumption. This affects 8.2 and HEAD only, since those functions weren't there earlier.
* Fix check_sql_fn_retval to allow the case where a SQL function declared toTom Lane2007-04-02
| | | | | | | | return void ends with a SELECT, if that SELECT has a single result that is also of type void. Without this, it's hard to write a void function that calls another void function. Per gripe from Peter. Back-patch as far as 8.0.
* SPI_cursor_open failed to enforce that only read-only queries could beTom Lane2007-03-17
| | | | | | | executed in read_only mode. This could lead to various relatively-subtle failures, such as an allegedly stable function returning non-stable results. Bug goes all the way back to the introduction of read-only mode in 8.0. Per report from Gaetano Mendola.
* Remove typmod checking from the recent security-related patches. It turnsTom Lane2007-02-06
| | | | | | | | | | | | | out that ExecEvalVar and friends don't necessarily have access to a tuple descriptor with correct typmod: it definitely can contain -1, and possibly might contain other values that are different from the Var's value. Arguably this should be cleaned up someday, but it's not a simple change, and in any case typmod discrepancies don't pose a security hazard. Per reports from numerous people :-( I'm not entirely sure whether the failure can occur in 8.0 --- the simple test cases reported so far don't trigger it there. But back-patch the change all the way anyway.
* Repair failure to check that a table is still compatible with a previouslyTom Lane2007-02-02
| | | | | | | | | | | | | | | | | | | | | | made query plan. Use of ALTER COLUMN TYPE creates a hazard for cached query plans: they could contain Vars that claim a column has a different type than it now has. Fix this by checking during plan startup that Vars at relation scan level match the current relation tuple descriptor. Since at that point we already have at least AccessShareLock, we can be sure the column type will not change underneath us later in the query. However, since a backend's locks do not conflict against itself, there is still a hole for an attacker to exploit: he could try to execute ALTER COLUMN TYPE while a query is in progress in the current backend. Seal that hole by rejecting ALTER TABLE whenever the target relation is already open in the current backend. This is a significant security hole: not only can one trivially crash the backend, but with appropriate misuse of pass-by-reference datatypes it is possible to read out arbitrary locations in the server process's memory, which could allow retrieving database content the user should not be able to see. Our thanks to Jeff Trout for the initial report. Security: CVE-2007-0556
* Repair insufficiently careful type checking for SQL-language functions:Tom Lane2007-02-02
| | | | | | | | | | | | | | | | we should check that the function code returns the claimed result datatype every time we parse the function for execution. Formerly, for simple scalar result types we assumed the creation-time check was sufficient, but this fails if the function selects from a table that's been redefined since then, and even more obviously fails if check_function_bodies had been OFF. This is a significant security hole: not only can one trivially crash the backend, but with appropriate misuse of pass-by-reference datatypes it is possible to read out arbitrary locations in the server process's memory, which could allow retrieving database content the user should not be able to see. Our thanks to Jeff Trout for the initial report. Security: CVE-2007-0555
* Relax an Assert() that has been found to be too strict in some situationsTom Lane2007-01-24
| | | | | | | involving unions of types having typmods. Variants of the failure are known to occur in 8.1 and up; not sure if it's possible in 8.0 and 7.4, but since the code exists that far back, I'll just patch 'em all. Per report from Brian Hurt.
* Repair bug #2839: the various ExecReScan functions need to resetTom Lane2006-12-26
| | | | | | | | | ps_TupFromTlist in plan nodes that make use of it. This was being done correctly in join nodes and Result nodes but not in any relation-scan nodes. Bug would lead to bogus results if a set-returning function appeared in the targetlist of a subquery that could be rescanned after partial execution, for example a subquery within EXISTS(). Bug has been around forever :-( ... surprising it wasn't reported before.
* Repair bug #2694 concerning an ARRAY[] construct whose inputs are emptyTom Lane2006-11-06
| | | | | | | | | | sub-arrays. Per discussion, if all inputs are empty arrays then result must be an empty array too, whereas a mix of empty and nonempty arrays should (and already did) draw an error. In the back branches, the construct was strict: any NULL input immediately yielded a NULL output; so I left that behavior alone. HEAD was simply ignoring NULL sub-arrays, which doesn't seem very sensible. For lack of a better idea it now treats NULL sub-arrays the same as empty ones.
* Fix mishandling of after-trigger state when a SQL function returns multipleTom Lane2006-10-12
| | | | | | | | | | rows --- if the surrounding query queued any trigger events between the rows, the events would be fired at the wrong time, leading to bizarre behavior. Per report from Merlin Moncure. This is a simple patch that should solve the problem fully in the back branches, but in HEAD we also need to consider the possibility of queries with RETURNING clauses. Will look into a fix for that separately.
* Fix SELECT INTO and CREATE TABLE AS to create tables in the defaultBruce Momjian2006-04-26
| | | | | | tablespace, not the base directory. Kris Jurka
* Fix bug introduced into mergejoin logic by performance improvement patch ofTom Lane2006-03-17
| | | | | | | | | | | | | | 2005-05-13. When we find that a new inner tuple can't possibly match any outer tuple (because it contains a NULL), we can't immediately skip the tuple when we are in NEXTINNER state. Doing so can lead to emitting multiple copies of the tuple in FillInner mode, because we may rescan the tuple after returning to a previous marked tuple. Instead, proceed to NEXTOUTER state the same as we used to do. After we've found that there's no need to return to the marked position, we can go to SKIPINNER_ADVANCE state instead of SKIP_TEST when the inner tuple is unmatchable; this preserves the performance improvement. Per bug report from Bruce. I also made a couple of cosmetic code rearrangements and added a regression test for the problem.
* Add a CHECK_FOR_INTERRUPTS() to the loop in ExecMakeTableFunctionResult.Tom Lane2006-03-10
| | | | Otherwise you can't cancel queries like select ... from generate_series(1,1000000).
* Repair "Halloween problem" in EvalPlanQual: a tuple that's been inserted byTom Lane2006-01-12
| | | | | | | | our own command (or more generally, xmin = our xact and cmin >= current command ID) should not be seen as good. Else we may try to update rows we already updated. This error was inserted last August while fixing the even bigger problem that the old coding wouldn't see *any* tuples inserted by our own transaction as good. Per report from Euler Taveira de Oliveira.
* Fix problem with whole-row Vars referencing sub-select outputs, perTom Lane2005-12-14
| | | | | example from Jim Dew. Add some simple regression tests, since this is an area we seem to break regularly :-(
* Rearrange code in ExecInitBitmapHeapScan so that we don't initialize theTom Lane2005-12-02
| | | | | | | | child plan nodes until we have acquired lock on the relation to scan. The relative order of initialization of plan nodes isn't real important in other cases, but it's critical here because one is supposed to lock a relation before its indexes, not vice versa. The original coding was at least vulnerable to deadlock against DROP INDEX, and perhaps worse things.
* Tweak hash join code to use an additional heuristic for deciding whetherTom Lane2005-11-28
| | | | | | | | it's worth probing the outer relation for emptiness before building the hash table. To wit, if we're rescanning a join previously performed, remember whether we found it nonempty the previous time, and don't bother with the probe if it was nonempty. This buys back the performance lost in examples like Mario Weilguni's.
* Recent changes to allow hash join to exit early given empty input fromTom Lane2005-11-28
| | | | | | | one child or the other had a problem: they did not leave the node in a state that ExecReScanHashJoin would understand. In particular it would tend to fail to reset the child plans when needed. Per report from Mario Weilguni.
* Get rid of ExecAssignResultTypeFromOuterPlan() and make all plan node typesTom Lane2005-11-23
| | | | | | | | | | | generate their output tuple descriptors from their target lists (ie, using ExecAssignResultTypeFromTL()). We long ago fixed things so that all node types have minimally valid tlists, so there's no longer any good reason to have two different ways of doing it. This change is needed to fix bug reported by Hayden James: the fix of 2005-11-03 to emit the correct column names after optimizing away a SubqueryScan node didn't work if the new top-level plan node used ExecAssignResultTypeFromOuterPlan to generate its tupdesc, since the next plan node down won't have the correct column labels.
* Re-run pgindent, fixing a problem where comment lines after a blankBruce Momjian2005-11-22
| | | | | | | | | comment line where output as too long, and update typedefs for /lib directory. Also fix case where identifiers were used as variable names in the backend, but as typedefs in ecpg (favor the backend for indenting). Backpatch to 8.1.X.
* Modify tuptoaster's API so that it does not try to modify the passedTom Lane2005-11-20
| | | | | | | | | tuple in-place, but instead passes back an all-new tuple structure if any changes are needed. This is a much cleaner and more robust solution for the bug discovered by Alexey Beschiokov; accordingly, revert the quick hack I installed yesterday. With this change, HeapTupleData.t_datamcxt is no longer needed; will remove it in a separate commit in HEAD only.
* Stopgap solution for problem reported by Alexey Beschiokov: afterTom Lane2005-11-19
| | | | | | | doing heap_insert or heap_update, wipe out any extracted fields in the TupleTableSlot containing the tuple, because they might not be valid anymore if tuptoaster.c changed the tuple. Safe because slot must be in the materialized state, but mighty ugly --- find a better answer!
* Prevent ExecInsert() and ExecUpdate() from scribbling on the result tupleTom Lane2005-11-14
| | | | | | | slot of the topmost plan node when a trigger returns a modified tuple. These appear to be the only places where a plan node's caller did not treat the result slot as read-only, which is an assumption that nodeUnique makes as of 8.1. Fixes trigger-vs-DISTINCT bug reported by Frank van Vugt.
* Rename the members of CommandDest enum so they don't collide with other uses ofAlvaro Herrera2005-11-03
| | | | | those names. (Debug and None were pretty bad names anyway.) I hope I catched all uses of the names in comments too.
* Better solution to the problem of labeling whole-row Datums that areTom Lane2005-10-19
| | | | | | generated from subquery outputs: use the type info stored in the Var itself. To avoid making ExecEvalVar and slot_getattr more complex and slower, I split out the whole-row case into a separate ExecEval routine.
* Ensure that the Datum generated from a whole-row Var contains validTom Lane2005-10-19
| | | | | | type ID information even when it's a record type. This is needed to handle whole-row Vars referencing subquery outputs. Per example from Richard Huxton.
* A few trivial code cleanups motivated by reading warnings generatedTom Lane2005-10-18
| | | | | by a recent HP C compiler. Mostly, get rid of useless local variables that are assigned to but never used.
* Standard pgindent run for 8.1.Bruce Momjian2005-10-15
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* Revise pgstats stuff to fix the problems with not counting accessesTom Lane2005-10-06
| | | | | | | generated by bitmap index scans. Along the way, simplify and speed up the code for counting sequential and index scans; it was both confusing and inefficient to be taking care of that in the per-tuple loops, IMHO. initdb forced because of internal changes in pg_stat view definitions.
* _SPI_execute_plan failed to return result tuple table to caller inTom Lane2005-10-01
| | | | | | | | | the ProcessUtility case, resulting in an intratransaction memory leak if a utility command actually did return any tuples, as reported by Dmitry Karasik. Fix this and also make the behavior more consistent for cases involving nested SPI operations and multiple query trees, by ensuring that we store the state locally until it is ready to be returned to the caller.
* The original patch to avoid building a hash join's hashtable when theTom Lane2005-09-25
| | | | | | | | outer relation is empty did not work, per test case from Patrick Welche. It tried to use nodeHashjoin.c's high-level mechanisms for fetching an outer-relation tuple, but that code expected the hash table to be filled already. As patched, the code failed in corner cases such as having no outer-relation tuples for the first hash batch. Revert and rewrite.
* Remove some dead code.Tom Lane2005-09-22
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* Tweak nodeBitmapAnd to stop evaluating sub-plan scans if it finds it'sTom Lane2005-08-28
| | | | | got an empty bitmap after any step; the remaining subplans can no longer affect the result. Per a suggestion from Ilia Kantor.
* Arrange for indexes and toast tables to inherit their ownership fromTom Lane2005-08-26
| | | | | | the parent table, even if the command that creates them is executed by someone else (such as a superuser or a member of the owning role). Per gripe from Michael Fuhr.
* Repair problems with VACUUM destroying t_ctid chains too soon, and withTom Lane2005-08-20
| | | | | | | | | | | | insufficient paranoia in code that follows t_ctid links. (We must do both because even with VACUUM doing it properly, the intermediate state with a dangling t_ctid link is visible concurrently during lazy VACUUM, and could be seen afterwards if either type of VACUUM crashes partway through.) Also try to improve documentation about what's going on. Patch is a bit bulky because passing the XMAX information around required changing the APIs of some low-level heapam.c routines, but it's not conceptually very complicated. Per trouble report from Teodor and subsequent analysis. This needs to be back-patched, but I'll do that after 8.1 beta is out.
* Update some obsolete comments --- code is using t_self now, not t_ctid.Tom Lane2005-08-18
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* Add NOWAIT option to SELECT FOR UPDATE/SHARE.Tom Lane2005-08-01
| | | | | Original patch by Hans-Juergen Schoenig, revisions by Karel Zak and Tom Lane.