attacks where an attacker would put <attack>\0<propername> in the field and
trick the validation code that the certificate was for <attack>.
This is a very low risk attack since it reuqires the attacker to trick the
CA into issuing a certificate with an incorrect field, and the common
PostgreSQL deployments are with private CAs, and not external ones. Also,
default mode in 8.4 does not do any name validation, and is thus also not
vulnerable - but the higher security modes are.
Backpatch all the way. Even though versions 8.3.x and before didn't have
certificate name validation support, they still exposed this field for
the user to perform the validation in the application code, and there
is no way to detect this problem through that API.
Security: CVE-2009-4034
in a subtransaction stays open even if the subtransaction is aborted, so
any temporary files related to it must stay alive as well. With the patch,
we use ResourceOwners to track open temporary files and don't automatically
close them at subtransaction end (though in the normal case temporary files
are registered with the subtransaction resource owner and will therefore be
closed).
At end of top transaction, we still check that there's no temporary files
marked as close-at-end-of-transaction open, but that's now just a debugging
cross-check as the resource owner cleanup should've closed them already.
This avoids a useless connection retry and complaint in the postmaster log
when receiving a connection from 8.5 or later libpq.
Backpatch in all supported branches, but of course *not* HEAD.
be part of multixacts, so allocate a slot for each prepared transaction in
the "oldest member" array in multixact.c. On PREPARE TRANSACTION, transfer
the oldest member value from the current backends slot to the prepared xact
slot. Also save and recover the value from the 2pc state file.
The symptom of the bug was that after a transaction prepared, a shared lock
still held by the prepared transaction was sometimes ignored by other
transactions.
Fix back to 8.1, where both 2PC and multixact were introduced.
output filename if CSV logging was enabled and only one of the two possible
output files got rotated during a particular call (which would, in fact,
typically be the case during a size-based rotation). This would amount to
about MAXPGPATH (1KB) per rotation, and it's been there since the CSV
code was put in, so it's surprising that nobody noticed it before.
Per bug #5196 from Thomas Poindessous.
non-Var sort/group expressions using ressortgroupref labels instead of
depending entirely on equal()-ity of the upper node's tlist expressions
to the lower node's. This avoids emitting the wrong outputs in cases
where there are textually identical volatile sort/group expressions,
as for example
select distinct random(),random() from generate_series(1,10);
Per report from Andrew Gierth.
Backpatch to 8.4. Arguably this is wrong all the way back, but the only known
case where there's an observable problem is when using hash aggregation to
implement DISTINCT, which is new as of 8.4. So for the moment I'll refrain
from backpatching further.
but the transformed ArrayExpr claimed to have a return type of "domain",
even though the domain constraint was only checked by the enclosing
CoerceToDomain node. With this fix, the ArrayExpr is correctly labeled with
the base type of the domain. Per gripe by Tom Lane.
we need to check domain constraints. We used to do it correctly, but 8.4
introduced a separate code path for the "ARRAY[]::arraytype" case to infer
the type of an empty ARRAY construct from the cast target, and forgot to take
domains into account.
Per report from Florian G. Pflug.
User-defined consistent functions believes the check array
contains at least one true element which was not a true for
scanning pending list.
Per report from Yury Don <yura@vpcit.ru>
In VACUUM FULL, an interrupt after the initial transaction has been recorded
as committed can cause postmaster to restart with the following error message:
PANIC: cannot abort transaction NNNN, it was already committed
This problem has been reported many times.
In lazy VACUUM, an interrupt after the table has been truncated by
lazy_truncate_heap causes other backends' relcache to still point to the
removed pages; this can cause future INSERT and UPDATE queries to error out
with the following error message:
could not read block XX of relation 1663/NNN/MMMM: read only 0 of 8192 bytes
The window to this race condition is extremely narrow, but it has been seen in
the wild involving a cancelled autovacuum process.
The solution for both problems is to inhibit interrupts in both operations
until after the respective transactions have been committed. It's not a
complete solution, because the transaction could theoretically be aborted by
some other error, but at least fixes the most common causes of both problems.
that are not handled by find_coercion_pathway, notably composite->RECORD.
Now that 8.4 supports composites as primary keys, it's worth dealing with
this case.
that it can scribble on scan->xs_ctup.t_self while following HOT chains,
so we can't rely on that to stay valid between hashgettuple() calls.
Introduce a private variable in HashScanOpaque, instead.
hash indexes keep entries sorted by hash value. First, the original plans for
concurrency assumed that insertions would happen only at the end of a page,
which is no longer true; this could cause scans to transiently fail to find
index entries in the presence of concurrent insertions. We can compensate
by teaching scans to re-find their position after re-acquiring read locks.
Second, neither the bucket split nor the bucket compaction logic had been
fixed to preserve hashvalue ordering, so application of either of those
processes could lead to permanent corruption of an index, in the sense
that searches might fail to find entries that are present.
This patch fixes the split and compaction logic to preserve hashvalue
ordering, but it cannot do anything about pre-existing corruption. We will
need to recommend reindexing all hash indexes in the 8.4.2 release notes.
To buy back the performance loss hereby induced in split and compaction,
fix them to use PageIndexMultiDelete instead of retail PageIndexDelete
operations. We might later want to do something with qsort'ing the
page contents rather than doing a binary search for each insertion,
but that seemed more invasive than I cared to risk in a back-patch.
Per bug #5157 from Jeff Janes and subsequent investigation.
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.
that it's called within an AfterTriggerBeginQuery/AfterTriggerEndQuery pair.
The RI cascade triggers suppress that overhead on the assumption that they
are always run non-deferred, so it's possible to violate the condition if
someone mistakenly changes pg_trigger to mark such a trigger deferred.
We don't really care about supporting that, but throwing an error instead
of crashing seems desirable. Per report from Marcelo Costa.
for example in
WITH w AS (SELECT * FROM foo) SELECT * FROM w, bar ... FOR UPDATE
the FOR UPDATE will now affect bar but not foo. This is more useful and
consistent than the original 8.4 behavior, which tried to propagate FOR UPDATE
into the WITH query but always failed due to assorted implementation
restrictions. Even though we are in process of removing those restrictions,
it seems correct on philosophical grounds to not let the outer query's
FOR UPDATE affect the WITH query.
In passing, fix isLockedRel which frequently got things wrong in
nested-subquery cases: "FOR UPDATE OF foo" applies to an alias foo in the
current query level, not subqueries. This has been broken for a long time,
but it doesn't seem worth back-patching further than 8.4 because the actual
consequences are minimal. At worst the parser would sometimes get
RowShareLock on a relation when it should be AccessShareLock or vice versa.
That would only make a difference if someone were using ExclusiveLock
concurrently, which no standard operation does, and anyway FOR UPDATE
doesn't result in visible changes so it's not clear that the someone would
notice any problem. Between that and the fact that FOR UPDATE barely works
with subqueries at all in existing releases, I'm not excited about worrying
about it.
pam_message array contains exactly one PAM_PROMPT_ECHO_OFF message.
Instead, deal with however many messages there are, and don't throw error
for PAM_ERROR_MSG and PAM_TEXT_INFO messages. This logic is borrowed from
openssh 5.2p1, which hopefully has seen more real-world PAM usage than we
have. Per bug #5121 from Ryan Douglas, which turned out to be caused by
the conv_proc being called with zero messages. Apparently that is normal
behavior given the combination of Linux pam_krb5 with MS Active Directory
as the domain controller.
Patch all the way back, since this code has been essentially untouched
since 7.4. (Surprising we've not heard complaints before.)
and SSPI athentication methods. While the old 2000 byte limit was more than
enough for Unix Kerberos implementations, tickets issued by Windows Domain
Controllers can be much larger.
Ian Turner
Also insert a couple of Asserts that check for stack overflow.
Bogus coding appears to be new in 8.4 --- older releases had a much
simpler algorithm here. Per bug #5111.
Partially revert the previous patch I installed and replace it with a more
general fix: any time a snapshot is pushed as Active, we need to ensure that it
will not be modified in the future. This means that if the same snapshot is
used as CurrentSnapshot, it needs to be copied separately. This affects
serializable transactions only, because CurrentSnapshot has already been copied
by RegisterSnapshot and so PushActiveSnapshot does not think it needs another
copy. However, CommandCounterIncrement would modify CurrentSnapshot, whereas
ActiveSnapshots must not have their command counters incremented.
I say "partially" because the regression test I added for the previous bug
has been kept.
(This restores 8.3 behavior, because before snapmgr.c existed, any snapshot set
as Active was copied.)
Per bug report from Stuart Bishop in
6bc73d4c0910042358k3d1adff3qa36f8df75198ecea@mail.gmail.com
inheritance parent tables are compared using equal(), instead of doing
strcmp() on the nodeToString representation. The old implementation was
always a tad cheesy, and it finally fails completely as of 8.4, now that the
node tree might contain syntax location information. equal() knows it's
supposed to ignore those fields, but strcmp() hardly can. Per recent
report from Scott Ribe.
large number of SIGHUP cycles, these would have run the postmaster out
of memory. Noted while testing memory-leak scenario in postgresql.conf
configuration-change-printing patch.
tuple size limit. Improve the error message for index-tuple-too-large
so that it includes the actual size, the limit, and the index name.
Sync with the btree occurrences of the same error.
Back-patch to 8.4 because it appears that the out-of-sync problem
is occurring in the field.
Teodor and Tom
in CREATE OR REPLACE FUNCTION. The original code would update pg_shdepend
as if a new function was being created, even if it wasn't, with two bad
consequences: pg_shdepend might record the wrong owner for the function,
and any dependencies for roles mentioned in the function's ACL would be lost.
The fix is very easy: just don't touch pg_shdepend at all when doing a
function replacement.
Also update the CREATE FUNCTION reference page, which never explained
exactly what changes and doesn't change in a function replacement.
In passing, fix the CREATE VIEW reference page similarly; there's no
code bug there, but the docs didn't say what happens.
The old coding was using a regular snapshot, referenced elsewhere, that was
subject to having its command counter updated. Fix by creating a private copy
of the snapshot exclusively for the cursor.
Backpatch to 8.4, which is when the bug was introduced during the snapshot
management rewrite.
The original coding correctly noted that these aren't just redundancies
(they're effectively X IS NOT NULL, assuming = is strict). However, they
got treated that way if X happened to be in a single-member EquivalenceClass
already, which could happen if there was an ORDER BY X clause, for instance.
The simplest and most reliable solution seems to be to not try to process
such clauses through the EquivalenceClass machinery; just throw them back
for traditional processing. The amount of work that'd be needed to be
smarter than that seems out of proportion to the benefit.
Per bug #5084 from Bernt Marius Johnsen, and analysis by Andrew Gierth.
possibility of shared-inval messages causing a relcache flush while it tries
to fill in missing data in preloaded relcache entries. There are actually
two distinct failure modes here:
1. The flush could delete the next-to-be-processed cache entry, causing
the subsequent hash_seq_search calls to go off into the weeds. This is
the problem reported by Michael Brown, and I believe it also accounts
for bug #5074. The simplest fix is to restart the hashtable scan after
we've read any new data from the catalogs. It appears that pre-8.4
branches have not suffered from this failure, because by chance there were
no other catalogs sharing the same hash chains with the catalogs that
RelationCacheInitializePhase2 had work to do for. However that's obviously
pretty fragile, and it seems possible that derivative versions with
additional system catalogs might be vulnerable, so I'm back-patching this
part of the fix anyway.
2. The flush could delete the *current* cache entry, in which case the
pointer to the newly-loaded data would end up being stored into an
already-deleted Relation struct. As long as it was still deleted, the only
consequence would be some leaked space in CacheMemoryContext. But it seems
possible that the Relation struct could already have been recycled, in
which case this represents a hard-to-reproduce clobber of cached data
structures, with unforeseeable consequences. The fix here is to pin the
entry while we work on it.
In passing, also change RelationCacheInitializePhase2 to Assert that
formrdesc() set up the relation's cached TupleDesc (rd_att) with the
correct type OID and hasoids values. This is more appropriate than
silently updating the values, because the original tupdesc might already
have been copied into the catcache. However this part of the patch is
not in HEAD because it fails due to some questionable recent changes in
formrdesc :-(. That will be cleaned up in a subsequent patch.
In practice these mistakes were always masked when full_page_writes was on,
because XLogInsert would always choose to log the full page, and then
ginRedoInsertListPage wouldn't try to do anything. But with full_page_writes
off a WAL replay failure was certain.
The GIN_INSERT_LISTPAGE record type could probably be eliminated entirely
in favor of using XLOG_HEAP_NEWPAGE, but I refrained from doing that now
since it would have required a significantly more invasive patch.
In passing do a little bit of code cleanup, including making the accounting
for free space on GIN list pages more precise. (This wasn't a bug as the
errors were always in the conservative direction.)
Per report from Simon. Back-patch to 8.4 which contains the identical code.
of checkpoint. Although the checkpoint has been written to WAL at that point
already, so that all data is safe, and we'll retry removing the WAL segment at
the next checkpoint, if such a failure persists we won't be able to remove any
other old WAL segments either and will eventually run out of disk space. It's
better to treat the failure as non-fatal, and move on to clean any other WAL
segment and continue with any other end-of-checkpoint cleanup.
We don't normally expect any such failures, but on Windows it can happen with
some anti-virus or backup software that lock files without FILE_SHARE_DELETE
flag.
Also, the loop in pgrename() to retry when the file is locked was broken. If a
file is locked on Windows, you get ERROR_SHARE_VIOLATION, not
ERROR_ACCESS_DENIED, at least on modern versions. Fix that, although I left
the check for ERROR_ACCESS_DENIED in there as well (presumably it was correct
in some environment), and added ERROR_LOCK_VIOLATION to be consistent with
similar checks in pgwin32_open(). Reduce the timeout on the loop from 30s to
10s, on the grounds that since it's been broken, we've effectively had a
timeout of 0s and no-one has complained, so a smaller timeout is actually
closer to the old behavior. A longer timeout would mean that if recycling a
WAL file fails because it's locked for some reason, InstallXLogFileSegment()
will hold ControlFileLock for longer, potentially blocking other backends, so
a long timeout isn't totally harmless.
While we're at it, set errno correctly in pgrename().
Backpatch to 8.2, which is the oldest version supported on Windows. The xlog.c
changes would make sense on other platforms and thus on older versions as
well, but since there's no such locking issues on other platforms, it's not
worth it.
In this case we generate two PathKey references to the expression (one for
DISTINCT and one for ORDER BY) and they really need to refer to the same
EquivalenceClass. However get_eclass_for_sort_expr was being overly paranoid
and creating two different EC's. Correct behavior is to use the SortGroupRef
index to decide whether two references to volatile expressions that are
equal() (ie textually equivalent) should be considered the same.
Backpatch to 8.4. Possibly this should be changed in 8.3 as well, but
I'll refrain in the absence of evidence of a visible failure in that branch.
Per bug #5049.
file handle on it, the file goes into "pending deletion" state where it
still shows up in directory listing, but isn't accessible otherwise. That
confuses RemoveOldXLogFiles(), making it think that the file hasn't been
archived yet, while it actually was, and it was deleted along with the .done
file.
Fix that by renaming the file with ".deleted" extension before deleting it.
Also check the return value of rename() and unlink(), so that if the removal
fails for any reason (e.g another process is holding the file locked), we
don't delete the .done file until the WAL file is really gone.
Backpatch to 8.2, which is the oldest version supported on Windows.
code was already okay with this, but the hack that obtained the output
column types of a recursive union in advance of doing real parse analysis
of the recursive union forgot to handle the case where there was an inner
WITH clause available to the non-recursive term. Best fix seems to be to
refactor so that we don't need the "throwaway" parse analysis step at all.
Instead, teach the transformSetOperationStmt code to set up the CTE's output
column information after it's processed the non-recursive term normally.
Per report from David Fetter.
specify an encoding explicitly, we used to treat it as being in database
encoding when we parsed it, but then perform a UTF-8 -> database encoding
conversion on it, which was completely bogus. It's now consistently treated as
UTF-8.
to unload and re-load the library.
The difficulty with unloading a library is that we haven't defined safe
protocols for doing so. In particular, there's no safe mechanism for
getting out of a "hook" function pointer unless libraries are unloaded
in reverse order of loading. And there's no mechanism at all for undefining
a custom GUC variable, so GUC would be left with a pointer to an old value
that might or might not still be valid, and very possibly wouldn't be in
the same place anymore.
While the unload and reload behavior had some usefulness in easing
development of new loadable libraries, it's of no use whatever to normal
users, so just disabling it isn't giving up that much. Someday we might
care to expend the effort to develop safe unload protocols; but even if
we did, there'd be little certainty that every third-party loadable module
was following them, so some security restrictions would still be needed.
Back-patch to 8.2; before that, LOAD was superuser-only anyway.
Security: unprivileged users could crash backend. CVE not assigned yet
functions.
This extends the previous patch that forbade SETting these variables inside
security-definer functions. RESET is equally a security hole, since it
would allow regaining privileges of the caller; furthermore it can trigger
Assert failures and perhaps other internal errors, since the code is not
expecting these variables to change in such contexts. The previous patch
did not cover this case because assign hooks don't really have enough
information, so move the responsibility for preventing this into guc.c.
Problem discovered by Heikki Linnakangas.
Security: no CVE assigned yet, extends CVE-2007-6600
to occur for division by zero, even though the code is carefully avoiding
that. All available evidence is that the only functions affected are
int24div, int48div, and int28div, so patch just those three functions to
include a "return" after the ereport() call.
Backpatch to 8.4 so that the fix can be tested in production builds.
For older branches our recommendation will continue to be to use -O1
on affected platforms (which are mostly non-mainstream anyway).
that's generated for a whole-row Var referencing the subquery, when the
subquery is in the nullable side of an outer join. The previous coding
instead put PlaceHolderVars around the elements of the RowExpr. The effect
was that when the outer join made the subquery outputs go to null, the
whole-row Var produced ROW(NULL,NULL,...) rather than just NULL. There
are arguments afoot about whether those things ought to be semantically
indistinguishable, but for the moment they are not entirely so, and the
planner needs to take care that its machinations preserve the difference.
Per bug #5025.
Making this feasible required refactoring ResolveNew() to allow more caller
control over what is substituted for a Var. I chose to make ResolveNew()
a wrapper around a new general-purpose function replace_rte_variables().
I also fixed the ancient bogosity that ResolveNew might fail to set
a query's hasSubLinks field after inserting a SubLink in it. Although
all current callers make sure that happens anyway, we've had bugs of that
sort before, and it seemed like a good time to install a proper solution.
Back-patch to 8.4. The problem can be demonstrated clear back to 8.0,
but the fix would be too invasive in earlier branches; not to mention
that people may be depending on the subtly-incorrect behavior. The
8.4 series is new enough that fixing this probably won't cause complaints,
but it might in older branches. Also, 8.4 shows the incorrect behavior
in more cases than older branches do, because it is able to flatten
subqueries in more cases.
