referencing table does not change the tuple's FK column(s), we don't bother
to check the PK table since the constraint was presumably already valid.
However, the check is still necessary if the tuple was inserted by our own
transaction, since in that case the INSERT trigger will conclude it need not
make the check (since its version of the tuple has been deleted). We got this
right for simple cases, but not when the insert and update are in different
subtransactions of the current top-level transaction; in such cases the FK
check would never be made at all. (Hence, problem dates back to 8.0 when
subtransactions were added --- it's actually the subtransaction version of a
bug fixed in 7.3.5.) Fix, and add regression test cases. Report and fix by
Affan Salman.
been broken since forever, but was not noticed because people seldom look
at raw parse trees. AFAIK, no impact on users except that debug_print_parse
might fail; but patch it all the way back anyway. Per report from Jeff Ross.
to prevent possible escalation of privilege. Provide new SECURITY
DEFINER functions with old behavior, but initially REVOKE ALL
from public for these functions. Per list discussion and design
proposed by Tom Lane.
This is a Linux kernel bug that apparently exists in every extant kernel
version: sometimes shmctl() will fail with EIDRM when EINVAL is correct.
We were assuming that EIDRM indicates a possible conflict with pre-existing
backends, and refusing to start the postmaster when this happens. Fortunately,
there does not seem to be any case where Linux can legitimately return EIDRM
(it doesn't track shmem segments in a way that would allow that), so we can
get away with just assuming that EIDRM means EINVAL on this platform.
Per reports from Michael Fuhr and Jon Lapham --- it's a bit surprising
we have not seen more reports, actually.
overruns (neither of which seem likely to be exploitable as security holes,
fortunately, since the provoker can't control the data written). One of
these is due to choosing to stomp on the output of a called function, which
is bad news in any case; make it treat the called functions' results as
read-only. Avoid some unnecessary palloc/pfree traffic too; it's not
really helpful to free small temporary objects, and again this is presuming
more than it ought to about the nature of the results of called functions.
Per report from Patrick Welche and additional code-reading by Imad.
The correct test for defined-ness is SvOK(sv), not anything involving
SvTYPE. Per bug #3415 from Matt Taylor.
Back-patch as far as 8.0; no apparent problem in 7.x.
create table foo (bar int default null default 3);
due to not thinking about the special-case handling of DEFAULT NULL.
Problem noticed while investigating bug #3396.
reassembled in the syslogger before writing to the log file. This prevents
partial messages from being written, which mucks up log rotation, and
messages from different backends being interleaved, which causes garbled
logs. Backport as far as 8.0, where the syslogger was introduced.
Tom Lane and Andrew Dunstan
large inputs. Also cause it to error out immediately if the result will
overflow, instead of grinding through a lot of calculation first.
Per gripe from Jim Nasby.
wrong data when dumping a bufferload that crosses a component-file boundary.
This probably has not been seen in the wild because (a) component files are
normally 1GB apiece and (b) non-block-aligned buffer usage is relatively
rare. But it's fairly easy to reproduce a problem if one reduces RELSEG_SIZE
in a test build. Kudos to Kurt Harriman for spotting the bug.
fail when used in a deferred trigger. Bug goes back to 8.0; no doubt the
reason it hadn't been noticed is that we've been discouraging use of
user-defined constraint triggers. Per report from Frank van Vugt.
had been taught not to do that ages ago, the SSL code was helpfully bleating
anyway. Resolves some recent reports such as bug #3266; however the
underlying cause of the related bug #2829 is still unclear.
wrong thing when inlining polymorphic SQL functions, because it was using the
function's declared return type where it should have used the actual result
type of the current call. In 8.1 and 8.2 this causes obvious failures even if
you don't have assertions turned on; in 8.0 and 7.4 it would only be a problem
if the inlined expression were used as an input to a function that did
run-time type determination on its inputs. Add a regression test, since this
is evidently an under-tested area.
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.
This is needed to allow a security-definer function to set a truly secure
value of search_path. Without it, a malicious user can use temporary objects
to execute code with the privileges of the security-definer function. Even
pushing the temp schema to the back of the search path is not quite good
enough, because a function or operator at the back of the path might still
capture control from one nearer the front due to having a more exact datatype
match. Hence, disable searching the temp schema altogether for functions and
operators.
Security: CVE-2007-2138
failed (due to lock conflicts or out-of-space). We might have already
extended the index's filesystem EOF before failing, causing the EOF to be
beyond what the metapage says is the last used page. Hence the invariant
maintained by the code needs to be "EOF is at or beyond last used page",
not "EOF is exactly the last used page". Problem was created by my patch
of 2006-11-19 that attempted to repair bug #2737. Since that was
back-patched to 7.4, this needs to be as well. Per report and test case
from Vlastimil Krejcir.
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.
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.
did not expect that a DEAD tuple could follow a RECENTLY_DEAD tuple in an
update chain, but because the OldestXmin rule for determining deadness is a
simplification of reality, it is possible for this situation to occur
(implying that the RECENTLY_DEAD tuple is in fact dead to all observers,
but this patch does not attempt to exploit that). The code would follow a
chain forward all the way, but then stop before a DEAD tuple when backing
up, meaning that not all of the chain got moved. This could lead to copying
the chain multiple times (resulting in duplicate copies of the live tuple at
its end), or leaving dangling index entries behind (which, aside from
generating warnings from later vacuums, creates a risk of wrong query
results or bogus duplicate-key errors once the heap slot the index entry
points to is repopulated).
The fix is to recheck HeapTupleSatisfiesVacuum while following a chain
forward, and to stop if a DEAD tuple is reached. Each contiguous group
of RECENTLY_DEAD tuples will therefore be copied as a separate chain.
The patch also adds a couple of extra sanity checks to verify correct
behavior.
Per report and test case from Pavan Deolasee.
POSIX-style timezone specs that don't exactly match any database entry will
be treated as having correct USA DST rules. Also, document that this can
be changed if you want to use some other DST rules with a POSIX zone spec.
We could consider changing localtime.c's TZDEFRULESTRING, but since that
facility can only deal with one DST transition rule, it seems fairly useless
now; might as well just plan to override it using a "posixrules" entry.
Backpatch as far as 8.0. There isn't much we can do in 7.x ... either your
libc gets it right, or it doesn't.
check_sql_fn_retval allows binary-compatibility cases, the expression
extracted from an inline-able SQL function might have a type that is only
binary-compatible with the declared function result type. To avoid possibly
changing the semantics of the expression, we should insert a RelabelType node
in such cases. This has only been shown to have bad consequences in recent
8.1 and up releases, but I suspect there may be failure cases in the older
branches too, so patch it all the way back. Per bug #3116 from Greg Mullane.
Along the way, fix an omission in eval_const_expressions_mutator: it failed
to copy the relabelformat field when processing a RelabelType. No known
observable failures from this, but it definitely isn't intended behavior.
portals using PORTAL_UTIL_SELECT strategy. This is currently significant only
for FETCH queries, which are supposed to include a count in the tag. Seems
it's been broken since 7.4, but nobody noticed before Knut Lehre.
get away with not (re)initializing a local variable if the variable is marked
"isconst" and not "isnull". Unfortunately it makes this decision after having
already freed the old value, meaning that something like
for i in 1..10 loop
declare c constant text := 'hi there';
leads to subsequent accesses to freed memory, and hence probably crashes.
(In particular, this is why Asif Ali Rehman's bug leads to crash and not
just an unexpectedly-NULL value for SQLERRM: SQLERRM is marked CONSTANT
and so triggers this error.)
The whole thing seems wrong on its face anyway: CONSTANT means that you can't
change the variable inside the block, not that the initializer expression is
guaranteed not to change value across successive block entries. Hence,
remove the "optimization" instead of trying to fix it.
DECLARE section needs to know about it. Formerly, everyplace besides DECLARE
that created variables needed to do "plpgsql_add_initdatums(NULL)" to prevent
those variables from being sucked up as part of a subsequent DECLARE block.
This is obviously error-prone, and in fact the SQLSTATE/SQLERRM patch had
failed to do it for those two variables, leading to the bug recently exhibited
by Asif Ali Rehman: a DECLARE within an exception handler tried to reinitialize
SQLERRM.
Although the SQLSTATE/SQLERRM patch isn't in any pre-8.1 branches, and so
I can't point to a demonstrable failure there, it seems wise to back-patch
this into the older branches anyway, just to keep the logic similar to HEAD.
thought that it didn't have to reposition the underlying tuplestore if the
portal is atEnd. But this is not so, because tuplestores have separate read
and write cursors ... and the read cursor hasn't moved from the start.
This mistake explains bug #2970 from William Zhang.
Note: the coding here is pretty inefficient, but given that no one has noticed
this bug until now, I'd say hardly anyone uses the case where the cursor has
been advanced before being persisted. So maybe it's not worth worrying about.
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.
Andrew Dunstan