Commit 08146775ac changed do_copy() to
temporarily scribble on pset.cur_cmd_source. That was a mighty ugly bit of
code in any case, but in particular it broke handleCopyIn's ability to tell
whether it was reading from the current script source file (in which case
pset.lineno should be incremented for each line of COPY data), or from
someplace else (in which case it shouldn't). The former case still worked,
the latter not so much. The visible effect was that line numbers reported
for errors in a script file would be wrong if there were an earlier \copy
that was reading anything other than inline-in-the-script-file data.
To fix, introduce another pset field that holds the file do_copy wants the
COPY code to use. This is a little bit ugly, but less so than passing the
file down explicitly through several layers that aren't COPY-specific.
Extracted from a larger patch by Kumar Rajeev Rastogi; that patch also
changes printing of COPY command tags, which is not a bug fix and shouldn't
get back-patched. This particular idea was from a suggestion by Amit
Khandekar, if I'm reading the thread correctly.
Back-patch to 9.2 where the faulty code was introduced.
The previous coding supposed that it could consider just a single join
condition in any one parameterized path for the foreign table. But in
reality, the parameterized-path machinery forces all join clauses that are
"movable to" the foreign table to be evaluated at that node; including
clauses that we might not consider safe to send across. Such cases would
result in an Assert failure in an assert-enabled build, and otherwise in
sending an unsafe clause to the foreign server, which might result in
errors or silently-wrong answers. A lesser problem was that the
cost/rowcount estimates generated for the parameterized path failed to
account for any additional join quals that get assigned to the scan.
To fix, rewrite postgresGetForeignPaths so that it correctly collects all
the movable quals for any one outer relation when generating parameterized
paths; we'll now generate just one path per outer relation not one per join
qual. Also fix bogus assumptions in postgresGetForeignPlan and
estimate_path_cost_size that only safe-to-send join quals will be
presented.
Based on complaint from Etsuro Fujita that the path costs were being
miscalculated, though this is significantly different from his proposed
patch.
A fake relcache entry can "own" a SmgrRelation object, like a regular
relcache entry. But when it was free'd, the owner field in SmgrRelation
was not cleared, so it was left pointing to free'd memory.
Amazingly this apparently hasn't caused crashes in practice, or we would've
heard about it earlier. Andres found this with Valgrind.
Report and fix by Andres Freund, with minor modifications by me. Backpatch
to all supported versions.
In make_ruledef and get_query_def, we have long used AcquireRewriteLocks
to ensure that the querytree we are about to deparse is up-to-date and
the schemas of the underlying relations aren't changing. Howwever, that
function thinks the query is about to be executed, so it acquires locks
that are stronger than necessary for the purpose of deparsing. Thus for
example, if pg_dump asks to deparse a rule that includes "INSERT INTO t",
we'd acquire RowExclusiveLock on t. That results in interference with
concurrent transactions that might for example ask for ShareLock on t.
Since pg_dump is documented as being purely read-only, this is unexpected.
(Worse, it used to actually be read-only; this behavior dates back only
to 8.1, cf commit ba4200246.)
Fix this by adding a parameter to AcquireRewriteLocks to tell it whether
we want the "real" execution locks or only AccessShareLock.
Report, diagnosis, and patch by Dean Rasheed. Back-patch to all supported
branches.
If walsender doesn't hear from the client for the time specified by
wal_sender_timeout, it will conclude the connection or client is dead, and
disconnect. When half of wal_sender_timeout has elapsed, it sends a ping
to the client, leaving it the remainig half of wal_sender_timeout to
respond. However, it only checked if half of wal_sender_timeout had elapsed
when it was about to sleep, so if it was busy sending WAL to the client for
long enough, it would not send the ping request in time. Then the client
would not know it needs to send a reply, and the walsender will disconnect
even though the client is still alive. Fix that.
Andres Freund, reviewed by Robert Haas, and some further changes by me.
Backpatch to 9.3. Earlier versions relied on the client to send the
keepalives on its own, and hence didn't have this problem.
We should allow this so that matviews can be referenced in UPDATE/DELETE
statements in READ COMMITTED isolation level. The requirement for that
is that a re-fetch by TID will see the same row version the query saw
earlier, which is true of matviews, so there's no reason for the
restriction. Per bug #9398.
Michael Paquier, after a suggestion by me
We were unlinking the permanent file, not the non-permanent one. But
since the stat collector already unlinks all permanent files on startup,
there was nothing for it to unlink. The non-permanent file remained in
place, and was copied to the permanent directory on shutdown, so in
effect no file was ever dropped.
Backpatch to 9.3, where the issue was introduced by commit 187492b6c2.
Before that, there were no per-database files and thus no file to drop
on DROP DATABASE.
Per report from Thom Brown.
Author: Tomáš Vondra
CheckRequiredParameterValues() should perform the checks if archive recovery
was requested, even if we are going to perform crash recovery first.
Reported by Kyotaro HORIGUCHI. Backpatch to 9.2, like the crash-then-archive
recovery mode.
When entering crash recovery followed by archive recovery, and the latest
checkpoint is a shutdown checkpoint, and there are no more WAL records to
replay before transitioning from crash to archive recovery, we would not
immediately allow read-only connections in hot standby mode even if we
could. That's because when starting from a shutdown checkpoint, we set
lastReplayedEndRecPtr incorrectly to the record before the checkpoint
record, instead of the checkpoint record itself. We don't run the redo
routine of the shutdown checkpoint record, but starting recovery from it
goes through the same motions, so it should be considered as replayed.
Reported by Kyotaro HORIGUCHI. All versions with hot standby are affected,
so backpatch to 9.0.
I changed the loop in 9.3 to use "goto send_failure" instead of "break" on
errors, but I missed this one case. It was a relatively harmless bug: if
the flush fails once it will most likely fail again as soon as we try to
flush the output again. But it's a bug nevertheless.
Report and fix by Andres Freund.
The regex code didn't have any provision for query cancel; which is
unsurprising given its non-Postgres origin, but still problematic since
some operations can take a long time. Introduce a callback function to
check for a pending query cancel or session termination request, and
call it in a couple of strategic spots where we can make the regex code
exit with an error indicator.
If we ever actually split out the regex code as a standalone library,
some additional work will be needed to let the cancel callback function
be specified externally to the library. But that's straightforward
(certainly so by comparison to putting the locale-dependent character
classification logic on a similar arms-length basis), and there seems
no need to do it right now.
A bigger issue is that there may be more places than these two where
we need to check for cancels. We can always add more checks later,
now that the infrastructure is in place.
Since there are known examples of not-terribly-long regexes that can
lock up a backend for a long time, back-patch to all supported branches.
I have hopes of fixing the known performance problems later, but adding
query cancel ability seems like a good idea even if they were all fixed.
Commit abf5c5c9a4 added a bogus while-
statement after the for(;;)-loop. It went unnoticed in testing, because
it was dead code.
Report by KONDO Mitsumasa. Backpatch to 9.3. The commit that introduced
this was also applied to 9.2, but not the bogus while-loop part, because
the code in 9.2 looks quite different.
We were resetting the tuple's HEAP_HOT_UPDATED flag as well as t_ctid on
WAL replay of a tuple-lock operation, which is incorrect when the tuple
is already updated.
Back-patch to 9.3. The clearing of both header elements was there
previously, but since no update could be present on a tuple that was
being locked, it was harmless.
Bug reported by Peter Geoghegan and Greg Stark in
CAM3SWZTMQiCi5PV5OWHb+bYkUcnCk=O67w0cSswPvV7XfUcU5g@mail.gmail.com and
CAM-w4HPTOeMT4KP0OJK+mGgzgcTOtLRTvFZyvD0O4aH-7dxo3Q@mail.gmail.com
respectively; diagnosis by Andres Freund.
If there are lots of uncommitted tuples at the end of the index range,
get_actual_variable_range() ends up fetching each one and doing an MVCC
visibility check on it, until it finally hits a visible tuple. This is
bad enough in isolation, considering that we don't need an exact answer
only an approximate one. But because the tuples are not yet committed,
each visibility check does a TransactionIdIsInProgress() test, which
involves scanning the ProcArray. When multiple sessions do this
concurrently, the ensuing contention results in horrid performance loss.
20X overall throughput loss on not-too-complicated queries is easy to
demonstrate in the back branches (though someone's made it noticeably
less bad in HEAD).
We can dodge the problem fairly effectively by using SnapshotDirty rather
than a normal MVCC snapshot. This will cause the index probe to take
uncommitted tuples as good, so that we incur only one tuple fetch and test
even if there are many such tuples. The extent to which this degrades the
estimate is debatable: it's possible the result is actually a more accurate
prediction than before, if the endmost tuple has become committed by the
time we actually execute the query being planned. In any case, it's not
very likely that it makes the estimate a lot worse.
SnapshotDirty will still reject tuples that are known committed dead, so
we won't give bogus answers if an invalid outlier has been deleted but not
yet vacuumed from the index. (Because btrees know how to mark such tuples
dead in the index, we shouldn't have a big performance problem in the case
that there are many of them at the end of the range.) This consideration
motivates not using SnapshotAny, which was also considered as a fix.
Note: the back branches were using SnapshotNow instead of an MVCC snapshot,
but the problem and solution are the same.
Per performance complaints from Bartlomiej Romanski, Josh Berkus, and
others. Back-patch to 9.0, where the issue was introduced (by commit
40608e7f94).
Most estimation functions apply estimate_expression_value to see if they
can reduce an expression to a constant; the key difference is that it
allows evaluation of stable as well as immutable functions in hopes of
ending up with a simple Const node. scalararraysel didn't get the memo
though, and neither did gincost_opexpr/gincost_scalararrayopexpr. Fix
that, and remove a now-unnecessary estimate_expression_value step in the
subsidiary function scalararraysel_containment.
Per complaint from Alexey Klyukin. Back-patch to 9.3. The problem
goes back further, but I'm hesitant to change estimation behavior in
long-stable release branches.
The SQL standard says that OVERLAPS should have a two-element row
constructor on each side. The original coding of OVERLAPS support in
our grammar attempted to extend that by allowing a single-element row
constructor, which it internally duplicated ... or tried to, anyway.
But that code has certainly not worked since our List infrastructure was
rewritten in 2004, and I'm none too sure it worked before that. As it
stands, it ends up building a List that includes itself, leading to
assorted undesirable behaviors later in the parser.
Even if it worked as intended, it'd be a bit evil because of the
possibility of duplicate evaluation of a volatile function that the user
had written only once. Given the lack of documentation, test cases, or
complaints, let's just get rid of the idea and only support the standard
syntax.
While we're at it, improve the error cursor positioning for the
wrong-number-of-arguments errors, and inline the makeOverlaps() function
since it's only called in one place anyway.
Per bug #9227 from Joshua Yanovski. Initial patch by Joshua Yanovski,
extended a bit by me.
The ASLR in Windows 8/Windows 2012 can break PostgreSQL's shared memory. It
doesn't fail every time (which is explained by the Random part in ASLR), but
can fail with errors abut failing to reserve shared memory region.
MauMau, reviewed by Craig Ringer
Since the temporary server started by "make check" uses "trust"
authentication, another user on the same machine could connect to it
as database superuser, and then potentially exploit the privileges of
the operating-system user who started the tests. We should change
the testing procedures to prevent this risk; but discussion is required
about the best way to do that, as well as more testing than is practical
for an undisclosed security problem. Besides, the same issue probably
affects some user-written test harnesses. So for the moment, we'll just
warn people against using "make check" when there are untrusted users on
the same machine.
In passing, remove some ancient advice that suggested making the
regression testing subtree world-writable if you'd built as root.
That looks dangerously insecure in modern contexts, and anyway we
should not be encouraging people to build Postgres as root.
Security: CVE-2014-0067
Coverity identified a number of places in which it couldn't prove that a
string being copied into a fixed-size buffer would fit. We believe that
most, perhaps all of these are in fact safe, or are copying data that is
coming from a trusted source so that any overrun is not really a security
issue. Nonetheless it seems prudent to forestall any risk by using
strlcpy() and similar functions.
Fixes by Peter Eisentraut and Jozef Mlich based on Coverity reports.
In addition, fix a potential null-pointer-dereference crash in
contrib/chkpass. The crypt(3) function is defined to return NULL on
failure, but chkpass.c didn't check for that before using the result.
The main practical case in which this could be an issue is if libc is
configured to refuse to execute unapproved hashing algorithms (e.g.,
"FIPS mode"). This ideally should've been a separate commit, but
since it touches code adjacent to one of the buffer overrun changes,
I included it in this commit to avoid last-minute merge issues.
This issue was reported by Honza Horak.
Security: CVE-2014-0065 for buffer overruns, CVE-2014-0066 for crypt()
Several functions, mostly type input functions, calculated an allocation
size such that the calculation wrapped to a small positive value when
arguments implied a sufficiently-large requirement. Writes past the end
of the inadvertent small allocation followed shortly thereafter.
Coverity identified the path_in() vulnerability; code inspection led to
the rest. In passing, add check_stack_depth() to prevent stack overflow
in related functions.
Back-patch to 8.4 (all supported versions). The non-comment hstore
changes touch code that did not exist in 8.4, so that part stops at 9.0.
Noah Misch and Heikki Linnakangas, reviewed by Tom Lane.
Security: CVE-2014-0064
Many server functions use the MAXDATELEN constant to size a buffer for
parsing or displaying a datetime value. It was much too small for the
longest possible interval output and slightly too small for certain
valid timestamp input, particularly input with a long timezone name.
The long input was rejected needlessly; the long output caused
interval_out() to overrun its buffer. ECPG's pgtypes library has a copy
of the vulnerable functions, which bore the same vulnerabilities along
with some of its own. In contrast to the server, certain long inputs
caused stack overflow rather than failing cleanly. Back-patch to 8.4
(all supported versions).
Reported by Daniel Schüssler, reviewed by Tom Lane.
Security: CVE-2014-0063
If the name lookups come to different conclusions due to concurrent
activity, we might perform some parts of the DDL on a different table
than other parts. At least in the case of CREATE INDEX, this can be
used to cause the permissions checks to be performed against a
different table than the index creation, allowing for a privilege
escalation attack.
This changes the calling convention for DefineIndex, CreateTrigger,
transformIndexStmt, transformAlterTableStmt, CheckIndexCompatible
(in 9.2 and newer), and AlterTable (in 9.1 and older). In addition,
CheckRelationOwnership is removed in 9.2 and newer and the calling
convention is changed in older branches. A field has also been added
to the Constraint node (FkConstraint in 8.4). Third-party code calling
these functions or using the Constraint node will require updating.
Report by Andres Freund. Patch by Robert Haas and Andres Freund,
reviewed by Tom Lane.
Security: CVE-2014-0062
The primary role of PL validators is to be called implicitly during
CREATE FUNCTION, but they are also normal functions that a user can call
explicitly. Add a permissions check to each validator to ensure that a
user cannot use explicit validator calls to achieve things he could not
otherwise achieve. Back-patch to 8.4 (all supported versions).
Non-core procedural language extensions ought to make the same two-line
change to their own validators.
Andres Freund, reviewed by Tom Lane and Noah Misch.
Security: CVE-2014-0061
Granting a role without ADMIN OPTION is supposed to prevent the grantee
from adding or removing members from the granted role. Issuing SET ROLE
before the GRANT bypassed that, because the role itself had an implicit
right to add or remove members. Plug that hole by recognizing that
implicit right only when the session user matches the current role.
Additionally, do not recognize it during a security-restricted operation
or during execution of a SECURITY DEFINER function. The restriction on
SECURITY DEFINER is not security-critical. However, it seems best for a
user testing his own SECURITY DEFINER function to see the same behavior
others will see. Back-patch to 8.4 (all supported versions).
The SQL standards do not conflate roles and users as PostgreSQL does;
only SQL roles have members, and only SQL users initiate sessions. An
application using PostgreSQL users and roles as SQL users and roles will
never attempt to grant membership in the role that is the session user,
so the implicit right to add or remove members will never arise.
The security impact was mostly that a role member could revoke access
from others, contrary to the wishes of his own grantor. Unapproved role
member additions are less notable, because the member can still largely
achieve that by creating a view or a SECURITY DEFINER function.
Reviewed by Andres Freund and Tom Lane. Reported, independently, by
Jonas Sundman and Noah Misch.
Security: CVE-2014-0060
This is needed on Windows to support contrib/postgres_fdw. Although it's
been broken since last March, we didn't notice until recently because there
were no active buildfarm members that complained about missing PGDLLIMPORT
marking. Efforts are underway to improve that situation, in support of
which we're delaying fixing some other cases of global variables that
should be marked PGDLLIMPORT. However, this case affects 9.3, so we
can't wait any longer to fix it.
I chose to mark DateOrder as well, though it's not strictly necessary
for postgres_fdw.
We should not assume that struct timeval.tv_sec is a long, because
it ain't necessarily. (POSIX says that it's a time_t, which might
well be 64 bits now or in the future; or for that matter might be
32 bits on machines with 64-bit longs.) Per buildfarm member panther.
Back-patch to 9.3 where the dubious coding was introduced.
DST law changes in Jordan; historical changes in Cuba.
Also, remove the zones Asia/Riyadh87, Asia/Riyadh88, and Asia/Riyadh89.
Per the upstream announcement:
The files solar87, solar88, and solar89 are no longer distributed.
They were a negative experiment -- that is, a demonstration that
tz data can represent solar time only with some difficulty and error.
Their presence in the distribution caused confusion, as Riyadh
civil time was generally not solar time in those years.
This documentation never got the word about the existence of check-world or
installcheck-world. Revise to recommend use of those, and document all the
subsidiary test suites. Do some minor wordsmithing elsewhere, too.
In passing, remove markup related to generation of plain-text regression
test instructions, since we don't do that anymore.
Back-patch to 9.1 where check-world was added. (installcheck-world exists
in 9.0; but since check-world doesn't, this patch would need additional
work to cover that branch, and it doesn't seem worth the effort.)
The documentation suggested using "echo | psql", but not the often-superior
alternative of a here-document. Also, be more direct about suggesting
that people avoid -c for multiple commands. Per discussion.
If there is a WAL segment with same ID but different TLI present in both
the WAL archive and pg_xlog, prefer the one with higher TLI. Before this
patch, the archive was polled first, for all expected TLIs, and only if no
file was found was pg_xlog scanned. This was a change in behavior from 9.3,
which first scanned archive and pg_xlog for the highest TLI, then archive
and pg_xlog for the next highest TLI and so forth. This patch reverts the
behavior back to what it was in 9.2.
The reason for this is that if for example you try to do archive recovery
to timeline 2, which branched off timeline 1, but the WAL for timeline 2 is
not archived yet, we would replay past the timeline switch point on
timeline 1 using the archived files, before even looking timeline 2's files
in pg_xlog
Report and patch by Kyotaro Horiguchi. Backpatch to 9.3 where the behavior
was changed.
Adjust handleCopyOut() to stop trying to write data once it's failed
one time. For typical cases such as out-of-disk-space or broken-pipe,
additional attempts aren't going to do anything but waste time, and
in any case clean truncation of the output seems like a better behavior
than randomly dropping blocks in the middle.
Also remove dubious (and misleadingly documented) attempt to force our way
out of COPY_OUT state if libpq didn't do that. If we did have a situation
like that, it'd be a bug in libpq and would be better fixed there, IMO.
We can hope that commit fa4440f516 took care
of any such problems, anyway.
Also fix longstanding bug in handleCopyIn(): PQputCopyEnd() only supports
a non-null errormsg parameter in protocol version 3, and will actively
fail if one is passed in version 2. This would've made our attempts
to get out of COPY_IN state after a failure into infinite loops when
talking to pre-7.4 servers.
Back-patch the COPY_OUT state change business back to 9.2 where it was
introduced, and the other two fixes into all supported branches.
Previously we were piggybacking on transaction ID parameters to freeze
multixacts; but since there isn't necessarily any relationship between
rates of Xid and multixact consumption, this turns out not to be a good
idea.
Therefore, we now have multixact-specific freezing parameters:
vacuum_multixact_freeze_min_age: when to remove multis as we come across
them in vacuum (default to 5 million, i.e. early in comparison to Xid's
default of 50 million)
vacuum_multixact_freeze_table_age: when to force whole-table scans
instead of scanning only the pages marked as not all visible in
visibility map (default to 150 million, same as for Xids). Whichever of
both which reaches the 150 million mark earlier will cause a whole-table
scan.
autovacuum_multixact_freeze_max_age: when for cause emergency,
uninterruptible whole-table scans (default to 400 million, double as
that for Xids). This means there shouldn't be more frequent emergency
vacuuming than previously, unless multixacts are being used very
rapidly.
Backpatch to 9.3 where multixacts were made to persist enough to require
freezing. To avoid an ABI break in 9.3, VacuumStmt has a couple of
fields in an unnatural place, and StdRdOptions is split in two so that
the newly added fields can go at the end.
Patch by me, reviewed by Robert Haas, with additional input from Andres
Freund and Tom Lane.
We used the length of the input string, not the de-escaped string, as
the trigger for NAMEDATALEN truncation. AFAICS this would only result
in sometimes printing a phony truncation warning; but it's just luck
that there was no worse problem, since we were violating the API spec
for truncate_identifier(). Per bug #9204 from Joshua Yanovski.
This has been wrong since the Unicode-identifier support was added,
so back-patch to all supported branches.
We have a practice of providing a "bread crumb" trail between the minor
versions where the migration section actually tells you to do something.
Historically that was just plain text, eg, "see the release notes for
9.2.4"; but if you're using a browser or PDF reader, it's a lot nicer
if it's a live hyperlink. So use "<xref>" instead. Any argument against
doing this vanished with the recent decommissioning of plain-text release
notes.
Vik Fearing
