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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
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.
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
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.
2006-10-04pgindent run for 8.2.Bruce Momjian
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
2006-07-31Change the bootstrap sequence so that toast tables for system catalogs areTom Lane
created in the bootstrap phase proper, rather than added after-the-fact by initdb. This is cleaner than before because it allows us to retire the undocumented ALTER TABLE ... CREATE TOAST TABLE command, but the real reason I'm doing it is so that toast tables of shared catalogs will now have predetermined OIDs. This will allow a reasonably clean solution to the problem of locking tables before we load their relcache entries, to appear in a forthcoming patch.
2006-07-14Remove 576 references of include files that were not needed.Bruce Momjian
2006-07-13Allow include files to compile own their own.Bruce Momjian
Strip unused include files out unused include files, and add needed includes to C files. The next step is to remove unused include files in C files.
2006-07-11Sort reference of include files, "A" - "F".Bruce Momjian
2006-07-03Code review for FILLFACTOR patch. Change WITH grammar as per earlierTom Lane
discussion (including making def_arg allow reserved words), add missed opt_definition for UNIQUE case. Put the reloptions support code in a less random place (I chose to make a new file access/common/reloptions.c). Eliminate header inclusion creep. Make the index options functions safely user-callable (seems like client apps might like to be able to test validity of options before trying to make an index). Reduce overhead for normal case with no options by allowing rd_options to be NULL. Fix some unmaintainably klugy code, including getting rid of Natts_pg_class_fixed at long last. Some stylistic cleanup too, and pay attention to keeping comments in sync with code. Documentation still needs work, though I did fix the omissions in catalogs.sgml and indexam.sgml.
2006-07-02Add FILLFACTOR to CREATE INDEX.Bruce Momjian
ITAGAKI Takahiro
2006-06-16Fix problems with cached tuple descriptors disappearing while still in useTom Lane
by creating a reference-count mechanism, similar to what we did a long time ago for catcache entries. The back branches have an ugly solution involving lots of extra copies, but this way is more efficient. Reference counting is only applied to tupdescs that are actually in caches --- there seems no need to use it for tupdescs that are generated in the executor, since they'll go away during plan shutdown by virtue of being in the per-query memory context. Neil Conway and Tom Lane
2006-04-30Improve the representation of FOR UPDATE/FOR SHARE so that we canTom Lane
support both FOR UPDATE and FOR SHARE in one command, as well as both NOWAIT and normal WAIT behavior. The more general code is actually simpler and cleaner.
2006-03-05Update copyright for 2006. Update scripts.Bruce Momjian
2006-02-28Extend the ExecInitNode API so that plan nodes receive a set of flagTom Lane
bits indicating which optional capabilities can actually be exercised at runtime. This will allow Sort and Material nodes, and perhaps later other nodes, to avoid unnecessary overhead in common cases. This commit just adds the infrastructure and arranges to pass the correct flag values down to plan nodes; none of the actual optimizations are here yet. I'm committing this separately in case anyone wants to measure the added overhead. (It should be negligible.) Simon Riggs and Tom Lane
2006-02-21Cleanup the usage of ScanDirection: use the symbolic names for theNeil Conway
possible ScanDirection alternatives rather than magic numbers (-1, 0, 1). Also, use the ScanDirection macros in a few places rather than directly checking whether `dir == ForwardScanDirection' and the like. Per patch from James William Pye. His patch also changed ScanDirection to be a "char" rather than an enum, which I haven't applied.
2006-02-19Add TABLESPACE and ON COMMIT clauses to CREATE TABLE AS. ON COMMIT isNeil Conway
required by the SQL standard, and TABLESPACE is useful functionality. Patch from Kris Jurka, minor editorialization by Neil Conway.
2006-01-12Repair "Halloween problem" in EvalPlanQual: a tuple that's been inserted byTom Lane
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.
2006-01-11Cosmetic code cleanup: fix a bunch of places that used "return (expr);"Neil Conway
rather than "return expr;" -- the latter style is used in most of the tree. I kept the parentheses when they were necessary or useful because the return expression was complex.
2006-01-07Add comment explaining why RelationOpenSmgr() call is not needed.Tom Lane
2005-12-02Adjust scan plan nodes to avoid getting an extra AccessShareLock on aTom Lane
relation if it's already been locked by execMain.c as either a result relation or a FOR UPDATE/SHARE relation. This avoids an extra trip to the shared lock manager state. Per my suggestion yesterday.
2005-11-22Re-run pgindent, fixing a problem where comment lines after a blankBruce Momjian
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.
2005-11-20Modify tuptoaster's API so that it does not try to modify the passedTom Lane
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.
2005-11-19Stopgap solution for problem reported by Alexey Beschiokov: afterTom Lane
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!
2005-11-18Update obsolete comment describing ExecDelete(), per Simon Riggs.Neil Conway
2005-11-14Prevent ExecInsert() and ExecUpdate() from scribbling on the result tupleTom Lane
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.
2005-10-15Standard pgindent run for 8.1.Bruce Momjian
2005-08-26Arrange for indexes and toast tables to inherit their ownership fromTom Lane
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.
2005-08-20Repair problems with VACUUM destroying t_ctid chains too soon, and withTom Lane
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.
2005-08-18Update some obsolete comments --- code is using t_self now, not t_ctid.Tom Lane
2005-08-01Add NOWAIT option to SELECT FOR UPDATE/SHARE.Tom Lane
Original patch by Hans-Juergen Schoenig, revisions by Karel Zak and Tom Lane.
2005-06-28Replace pg_shadow and pg_group by new role-capable catalogs pg_authidTom Lane
and pg_auth_members. There are still many loose ends to finish in this patch (no documentation, no regression tests, no pg_dump support for instance). But I'm going to commit it now anyway so that Alvaro can make some progress on shared dependencies. The catalog changes should be pretty much done.
2005-06-20Avoid WAL-logging individual tuple insertions during CREATE TABLE ASTom Lane
(a/k/a SELECT INTO). Instead, flush and fsync the whole relation before committing. We do still need the WAL log when PITR is active, however. Simon Riggs and Tom Lane.
2005-05-22Teach the planner to remove SubqueryScan nodes from the plan if theyTom Lane
aren't doing anything useful (ie, neither selection nor projection). Also, extend to SubqueryScan the hacks already in place to avoid unnecessary ExecProject calls when the result would just be the same tuple the subquery already delivered. This saves some overhead in UNION and other set operations, as well as avoiding overhead for unflatten-able subqueries. Per example from Sokolov Yura.
2005-05-06For some reason access/tupmacs.h has been #including utils/memutils.h,Tom Lane
which is neither needed by nor related to that header. Remove the bogus inclusion and instead include the header in those C files that actually need it. Also fix unnecessary inclusions and bad inclusion order in tsearch2 files.
2005-04-28Implement sharable row-level locks, and use them for foreign key referencesTom Lane
to eliminate unnecessary deadlocks. This commit adds SELECT ... FOR SHARE paralleling SELECT ... FOR UPDATE. The implementation uses a new SLRU data structure (managed much like pg_subtrans) to represent multiple- transaction-ID sets. When more than one transaction is holding a shared lock on a particular row, we create a MultiXactId representing that set of transactions and store its ID in the row's XMAX. This scheme allows an effectively unlimited number of row locks, just as we did before, while not costing any extra overhead except when a shared lock actually has to be shared. Still TODO: use the regular lock manager to control the grant order when multiple backends are waiting for a row lock. Alvaro Herrera and Tom Lane.
2005-04-14First phase of project to use fixed OIDs for all system catalogs andTom Lane
indexes. Extend the macros in include/catalog/*.h to carry the info about hand-assigned OIDs, and adjust the genbki script and bootstrap code to make the relations actually get those OIDs. Remove the small number of RelOid_pg_foo macros that we had in favor of a complete set named like the catname.h and indexing.h macros. Next phase will get rid of internal use of names for looking up catalogs and indexes; but this completes the changes forcing an initdb, so it looks like a good place to commit. Along the way, I made the shared relations (pg_database etc) not be 'bootstrap' relations any more, so as to reduce the number of hardwired entries and simplify changing those relations in future. I'm not sure whether they ever really needed to be handled as bootstrap relations, but it seems to work fine to not do so now.
2005-04-06Merge Resdom nodes into TargetEntry nodes to simplify code and save aTom Lane
few palloc's. I also chose to eliminate the restype and restypmod fields entirely, since they are redundant with information stored in the node's contained expression; re-examining the expression at need seems simpler and more reliable than trying to keep restype/restypmod up to date. initdb forced due to change in contents of stored rules.
2005-03-25Improve EXPLAIN ANALYZE to show the time spent in each trigger whenTom Lane
executing a statement that fires triggers. Formerly this time was included in "Total runtime" but not otherwise accounted for. As a side benefit, we avoid re-opening relations when firing non-deferred AFTER triggers, because the trigger code can re-use the main executor's ResultRelInfo data structure.
2005-03-20Change the return value of HeapTupleSatisfiesUpdate() to be an enum,Neil Conway
rather than an integer, and fix the associated fallout. From Alvaro Herrera.
2005-03-16Revise TupleTableSlot code to avoid unnecessary construction and disassemblyTom Lane
of tuples when passing data up through multiple plan nodes. A slot can now hold either a normal "physical" HeapTuple, or a "virtual" tuple consisting of Datum/isnull arrays. Upper plan levels can usually just copy the Datum arrays, avoiding heap_formtuple() and possible subsequent nocachegetattr() calls to extract the data again. This work extends Atsushi Ogawa's earlier patch, which provided the key idea of adding Datum arrays to TupleTableSlots. (I believe however that something like this was foreseen way back in Berkeley days --- see the old comment on ExecProject.) A test case involving many levels of join of fairly wide tables (about 80 columns altogether) showed about 3x overall speedup, though simple queries will probably not be helped very much. I have also duplicated some code in heaptuple.c in order to provide versions of heap_formtuple and friends that use "bool" arrays to indicate null attributes, instead of the old convention of "char" arrays containing either 'n' or ' '. This provides a better match to the convention used by ExecEvalExpr. While I have not made a concerted effort to get rid of uses of the old routines, I think they should be deprecated and eventually removed.
2005-01-14Update obsolete comment, per Alvaro.Tom Lane
2004-12-31Tag appropriate files for rc3PostgreSQL Daemon
Also performed an initial run through of upgrading our Copyright date to extend to 2005 ... first run here was very simple ... change everything where: grep 1996-2004 && the word 'Copyright' ... scanned through the generated list with 'less' first, and after, to make sure that I only picked up the right entries ...
2004-10-07Fix problems with SQL functions returning rowtypes that have droppedTom Lane
columns. The returned tuple needs to have appropriate NULL columns inserted so that it actually matches the declared rowtype. It seemed convenient to use a JunkFilter for this, so I made some cleanups and simplifications in the JunkFilter code to allow it to support this additional functionality. (That in turn exposed a latent bug in nodeAppend.c, which is that it was returning a tuple slot whose descriptor didn't match its data.) Also, move check_sql_fn_retval out of pg_proc.c and into functions.c, where it seems to more naturally belong.
2004-09-13Redesign query-snapshot timing so that volatile functions in READ COMMITTEDTom Lane
mode see a fresh snapshot for each command in the function, rather than using the latest interactive command's snapshot. Also, suppress fresh snapshots as well as CommandCounterIncrement inside STABLE and IMMUTABLE functions, instead using the snapshot taken for the most closely nested regular query. (This behavior is only sane for read-only functions, so the patch also enforces that such functions contain only SELECT commands.) As per my proposal of 6-Sep-2004; I note that I floated essentially the same proposal on 19-Jun-2002, but that discussion tailed off without any action. Since 8.0 seems like the right place to be taking possibly nontrivial backwards compatibility hits, let's get it done now.
2004-09-11Renumber SnapshotNow and the other special snapshot codes so thatTom Lane
((Snapshot) NULL) can no longer be confused with a valid snapshot, as per my recent suggestion. Define a macro InvalidSnapshot for 0. Use InvalidSnapshot instead of SnapshotAny as the do-nothing special case for heap_update and heap_delete crosschecks; this seems a little cleaner even though the behavior is really the same.
2004-08-29Pgindent run for 8.0.Bruce Momjian
2004-08-29Update copyright to 2004.Bruce Momjian