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2009-12-29Previous fix for temporary file management broke returning a set fromHeikki Linnakangas
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.
2009-12-09Prevent indirect security attacks via changing session-local state withinTom Lane
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
2009-10-30Make the overflow guards in ExecChooseHashTableSize be more protective.Tom Lane
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.
2009-03-30Fix an oversight in the support for storing/retrieving "minimal tuples" inTom Lane
TupleTableSlots. We have functions for retrieving a minimal tuple from a slot after storing a regular tuple in it, or vice versa; but these were implemented by converting the internal storage from one format to the other. The problem with that is it invalidates any pass-by-reference Datums that were already fetched from the slot, since they'll be pointing into the just-freed version of the tuple. The known problem cases involve fetching both a whole-row variable and a pass-by-reference value from a slot that is fed from a tuplestore or tuplesort object. The added regression tests illustrate some simple cases, but there may be other failure scenarios traceable to the same bug. Note that the added tests probably only fail on unpatched code if it's built with --enable-cassert; otherwise the bug leads to fetching from freed memory, which will not have been overwritten without additional conditions. Fix by allowing a slot to contain both formats simultaneously; which turns out not to complicate the logic much at all, if anything it seems less contorted than before. Back-patch to 8.2, where minimal tuples were introduced.
2009-01-07Insert conditional SPI_push/SPI_pop calls into InputFunctionCall,Tom Lane
OutputFunctionCall, and friends. This allows SPI-using functions to invoke datatype I/O without concern for the possibility that a SPI-using function will be called (which could be either the I/O function itself, or a function used in a domain check constraint). It's a tad ugly, but not nearly as ugly as what'd be needed to make this work via retail insertion of push/pop operations in all the PLs. This reverts my patch of 2007-01-30 that inserted some retail SPI_push/pop calls into plpgsql; that approach only fixed plpgsql, and not any other PLs. But the other PLs have the issue too, as illustrated by a recent gripe from Christian Schröder. Back-patch to 8.2, which is as far back as this solution will work. It's also as far back as we need to worry about the domain-constraint case, since earlier versions did not attempt to check domain constraints within datatype input. I'm not aware of any old I/O functions that use SPI themselves, so this should be sufficient for a back-patch.
2008-12-01Ensure that the contents of a holdable cursor don't depend on out-of-lineTom Lane
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.
2008-10-16Fix a small memory leak in ExecReScanAgg() in the hashed aggregation case.Neil Conway
In the previous coding, the list of columns that needed to be hashed on was allocated in the per-query context, but we reallocated every time the Agg node was rescanned. Since this information doesn't change over a rescan, just construct the list of columns once during ExecInitAgg().
2008-10-16Fix SPI_getvalue and SPI_getbinval to range-check the given attribute numberTom Lane
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.
2008-08-08Install checks in executor startup to ensure that the tuples produced by anTom Lane
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.
2008-08-05Do not allow Unique nodes to be scanned backwards. The code claimed that itTom Lane
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.
2008-07-10Fix mis-calculation of extParam/allParam sets for plan nodes, as seen inTom Lane
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.
2008-02-29Fix several memory leaks when rescanning SRFs. Arrange for an SRF'sNeil Conway
"multi_call_ctx" to be a distinct sub-context of the EState's per-query context, and delete the multi_call_ctx as soon as the SRF finishes execution. This avoids leaking SRF memory until the end of the current query, which is particularly egregious when the SRF is scanned multiple times. This change also fixes a leak of the fields of the AttInMetadata struct in shutdown_MultiFuncCall(). Also fix a leak of the SRF result TupleDesc when rescanning a FunctionScan node. The TupleDesc is allocated in the per-query context for every call to ExecMakeTableFunctionResult(), so we should free it after calling that function. Since the SRF might choose to return a non-expendable TupleDesc, we only free the TupleDesc if it is not being reference-counted. Backpatch to 8.3 and 8.2 stable branches.
2007-08-31Extend whole-row Var evaluation to cope with the case that the sub-planTom Lane
generating the tuples has resjunk output columns. This is not possible for simple table scans but can happen when evaluating a whole-row Var for a view. Per example from Patryk Kordylewski. The problem exists back to 8.0 but I'm not going to risk back-patching further than 8.2 because of the many changes in this area.
2007-08-15Repair problems occurring when multiple RI updates have to be done to the sameTom Lane
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.
2007-08-08Fix a gradual memory leak in ExecReScanAgg(). Because the aggregationNeil Conway
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.
2007-06-01Fix performance problems in multi-batch hash joins by ensuring that we selectTom Lane
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.
2007-04-26Fix dynahash.c to suppress hash bucket splits while a hash_seq_search() scanTom Lane
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.
2007-04-02Fix check_sql_fn_retval to allow the case where a SQL function declared toTom Lane
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.
2007-03-17SPI_cursor_open failed to enforce that only read-only queries could beTom Lane
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.
2007-02-16Fix another problem in 8.2 changes that allowed "one-time" qual conditions toTom Lane
be checked at plan levels below the top; namely, we have to allow for Result nodes inserted just above a nestloop inner indexscan. Should think about using the general Param mechanism to pass down outer-relation variables, but for the moment we need a back-patchable solution. Per report from Phil Frost.
2007-02-15Repair oversight in 8.2 change that improved the handling of "pseudoconstant"Tom Lane
WHERE clauses. createplan.c is now willing to stick a gating Result node almost anywhere in the plan tree, and in particular one can wind up directly underneath a MergeJoin node. This means it had better be willing to handle Mark/Restore. Fortunately, that's trivial in such cases, since we can just pass off the call to the input node (which the planner has previously ensured can handle Mark/Restore). Per report from Phil Frost.
2007-02-06Remove typmod checking from the recent security-related patches. It turnsTom Lane
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.
2007-02-02Repair failure to check that a table is still compatible with a previouslyTom Lane
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
2007-02-02Repair insufficiently careful type checking for SQL-language functions:Tom Lane
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
2007-01-24Relax an Assert() that has been found to be too strict in some situationsTom Lane
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.
2006-12-26Fix failure due to accessing an already-freed tuple descriptor in a planTom Lane
involving HashAggregate over SubqueryScan (this is the known case, there may well be more). The bug is only latent in releases before 8.2 since they didn't try to access tupletable slots' descriptors during ExecDropTupleTable. The least bogus fix seems to be to make subqueries share the parent query's memory context, so that tupdescs they create will have the same lifespan as those of the parent query. There are comments in the code envisioning going even further by not having a separate child EState at all, but that will require rethinking executor access to range tables, which I don't want to tackle right now. Per bug report from Jean-Pierre Pelletier.
2006-12-26Repair bug #2839: the various ExecReScan functions need to resetTom Lane
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.
2006-12-26Repair bug #2836: SPI_execute_plan returned zero if none of the querytreesTom Lane
were marked canSetTag. While it's certainly correct to return the result of the last one that is marked canSetTag, it's less clear what to do when none of them are. Since plpgsql will complain if zero is returned, the 8.2.0 behavior isn't good. I've fixed it to restore the prior behavior of returning the physically last query's result code when there are no canSetTag queries.
2006-12-08Avoid double free of _SPI_current->tuptable. AtEOSubXact_SPI() now tries toTom Lane
release it in a subtransaction abort, but this neglects possibility that someone outside SPI already did. Fix is for spi.c to forget about a tuptable as soon as it's handed it back to the caller. Per bug #2817 from Michael Andreen.
2006-12-03Fix LIMIT/OFFSET for null limit values. This worked before 8.2 but was brokenTom Lane
by the change to make limit values int8 instead of int4. (Specifically, you can do DatumGetInt32 safely on a null value, but not DatumGetInt64.) Per bug #2803 from Greg Johnson.
2006-11-21Prevent intratransaction memory leak when a subtransaction is abortedTom Lane
in the middle of executing a SPI query. This doesn't entirely fix the problem of memory leakage in plpgsql exception handling, but it should get rid of the lion's share of leakage.
2006-11-17Small message equalization fixPeter Eisentraut
2006-11-08Remove a 15-year old comment questioning behavior that is now well-Neil Conway
established: referencing an undefined parameter should result in an error, not NULL.
2006-11-06Repair bug #2694 concerning an ARRAY[] construct whose inputs are emptyTom Lane
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.
2006-10-12Fix mishandling of after-trigger state when a SQL function returns multipleTom Lane
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.
2006-10-06Message style improvementsPeter Eisentraut
2006-10-04pgindent run for 8.2.Bruce Momjian
2006-09-28Fix IS NULL and IS NOT NULL tests on row-valued expressions to conform toTom Lane
the SQL spec, viz IS NULL is true if all the row's fields are null, IS NOT NULL is true if all the row's fields are not null. The former coding got this right for a limited number of cases with IS NULL (ie, those where it could disassemble a ROW constructor at parse time), but was entirely wrong for IS NOT NULL. Per report from Teodor. I desisted from changing the behavior for arrays, since on closer inspection it's not clear that there's any support for that in the SQL spec. This probably needs more consideration.
2006-09-07Clean up logging for extended-query-protocol operations, as per my recentTom Lane
proposal. Parameter logging works even for binary-format parameters, and logging overhead is avoided when disabled. log_statement = all output for the src/test/examples/testlibpq3.c example now looks like LOG: statement: execute <unnamed>: SELECT * FROM test1 WHERE t = $1 DETAIL: parameters: $1 = 'joe''s place' LOG: statement: execute <unnamed>: SELECT * FROM test1 WHERE i = $1::int4 DETAIL: parameters: $1 = '2' and log_min_duration_statement = 0 results in LOG: duration: 2.431 ms parse <unnamed>: SELECT * FROM test1 WHERE t = $1 LOG: duration: 2.335 ms bind <unnamed> to <unnamed>: SELECT * FROM test1 WHERE t = $1 DETAIL: parameters: $1 = 'joe''s place' LOG: duration: 0.394 ms execute <unnamed>: SELECT * FROM test1 WHERE t = $1 DETAIL: parameters: $1 = 'joe''s place' LOG: duration: 1.251 ms parse <unnamed>: SELECT * FROM test1 WHERE i = $1::int4 LOG: duration: 0.566 ms bind <unnamed> to <unnamed>: SELECT * FROM test1 WHERE i = $1::int4 DETAIL: parameters: $1 = '2' LOG: duration: 0.173 ms execute <unnamed>: SELECT * FROM test1 WHERE i = $1::int4 DETAIL: parameters: $1 = '2' (This example demonstrates the folly of ignoring parse/bind steps for duration logging purposes, BTW.) Along the way, create a less ad-hoc mechanism for determining which commands are logged by log_statement = mod and log_statement = ddl. The former coding was actually missing quite a few things that look like ddl to me, and it did not handle EXECUTE or extended query protocol correctly at all. This commit does not do anything about the question of whether log_duration should be removed or made less redundant with log_min_duration_statement.
2006-09-06Change processing of extended-Query mode so that an unnamed statementTom Lane
that has parameters is always planned afresh for each Bind command, treating the parameter values as constants in the planner. This removes the performance penalty formerly often paid for using out-of-line parameters --- with this definition, the planner can do constant folding, LIKE optimization, etc. After a suggestion by Andrew@supernews.
2006-09-03Revert FETCH/MOVE int64 patch. Was using incorrect checks forBruce Momjian
fetch/move in scan.l.
2006-09-02Change FETCH/MOVE to use int8.Bruce Momjian
Dhanaraj M
2006-08-29Now bind displays prepare as detail, and execute displays prepare andBruce Momjian
optionally bind. I re-added the "statement:" label so people will understand why the line is being printed (it is log_*statement behavior). Use single quotes for bind values, instead of double quotes, and double literal single quotes in bind values (and document that). I also made use of the DETAIL line to have much cleaner output.
2006-08-27Add new return codes SPI_OK_INSERT_RETURNING etc to the SPI API.Tom Lane
Fix all the standard PLs to be able to return tuples from FOO_RETURNING statements as well as utility statements that return tuples. Also, fix oversight that SPI_processed wasn't set for a utility statement returning tuples. Per recent discussion.
2006-08-14Fix oversight in initial implementation of PORTAL_ONE_RETURNING mode: weTom Lane
cannot assume that there's exactly one Query in the Portal, as we can for ONE_SELECT mode, because non-SELECT queries might have extra queries added during rule rewrites. Fix things up so that we'll use ONE_RETURNING mode when a Portal contains one primary (canSetTag) query and that query has a RETURNING list. This appears to be a second showstopper reason for running the Portal to completion before we start to hand anything back --- we want to be sure that the rule-added queries get run too.
2006-08-14When executing a list of queries derived from rule expansion,Tom Lane
_SPI_execute_plan's return code should reflect the type of the query that is marked canSetTag, not necessarily the last one in the list. This is arguably a bug fix, but I'm hesitant to back-patch it because it's the sort of subtle change that might break someone's code, and it's best not to do that kind of thing in point releases.
2006-08-12Tweak SPI_cursor_open to allow INSERT/UPDATE/DELETE RETURNING; this wasTom Lane
merely a matter of fixing the error check, since the underlying Portal infrastructure already handles it. This in turn allows these statements to be used in some existing plpgsql and plperl contexts, such as a plpgsql FOR loop. Also, do some marginal code cleanup in places that were being sloppy about distinguishing SELECT from SELECT INTO.
2006-08-12Add INSERT/UPDATE/DELETE RETURNING, with basic docs and regression tests.Tom Lane
plpgsql support to come later. Along the way, convert execMain's SELECT INTO support into a DestReceiver, in order to eliminate some ugly special cases. Jonah Harris and Tom Lane
2006-08-08For protocol-level prepare/bind/execute:Bruce Momjian
o print user name for all o print portal name if defined for all o print query for all o reduce log_statement header to single keyword o print bind parameters as DETAIL if text mode
2006-08-04Fix domain_in() bug exhibited by Darcy Buskermolen. The idea of an EStateTom Lane
that's shorter-lived than the expression state being evaluated in it really doesn't work :-( --- we end up with fn_extra caches getting deleted while still in use. Rather than abandon the notion of caching expression state across domain_in calls altogether, I chose to make domain_in a bit cozier with ExprContext. All we really need for evaluating variable-free expressions is an ExprContext, not an EState, so I invented the notion of a "standalone" ExprContext. domain_in can prevent resource leakages by doing a ReScanExprContext on this rather than having to free it entirely; so we can make the ExprContext have the same lifespan (and particularly the same per_query memory context) as the expression state structs.