checkExtensionMembership() set the DUMP_COMPONENT_SECLABEL and
DUMP_COMPONENT_POLICY flags for extension member objects, even though
we lack any infrastructure for tracking extensions' initial settings
of these properties. This is not OK. The result was that a dump
would always include commands to set these properties for extension
objects that have them, with at least three negative consequences:
1. The restoring user might not have privilege to set these properties
on these objects.
2. The properties might be incorrect/irrelevant for the version of the
extension that's installed in the destination database.
3. The dump itself might fail, in the case of RLS properties attached
to extension tables that the dumping user lacks privilege to LOCK.
(That's because we must get at least AccessShareLock to ensure that
we don't fail while trying to decompile the RLS expressions.)
When and if somebody cares to invent initial-state infrastructure for
extensions' RLS policies and security labels, we could think about
finding another way around problem #3. But in the absence of such
infrastructure, this whole thing is just wrong and we shouldn't do it.
(Note: this applies only to ordinary dumps; binary-upgrade dumps
still dump and restore extension member objects separately, with
all properties.)
Tom Lane and Jacob Champion. Back-patch to all supported branches.
Discussion: https://postgr.es/m/00d46a48-3324-d9a0-49bf-e7f0f11d1038@timescale.com
It's clearly stated in the comments that ginFindParents() must keep
the pin on the index's root page that's associated with the topmost
GinBtreeStack item. However, the code path for the case that the
desired downlink has been pushed down to the next index level
ignored this proviso, and would release the pin anyway if we were
still examining the root level. That led to an assertion failure
or "buffer NNNN is not owned by resource owner" error later, when
we try to release the pin again at the end of the insertion.
This is quite hard to reproduce, since it can only happen if an
index root page split occurs concurrently with our own insertion.
Thanks to Jeff Janes for finding a test case that triggers it
often enough to allow investigation.
This has been there since the beginning of GIN, so back-patch
to all supported branches.
Discussion: https://postgr.es/m/CAMkU=1yCAKtv86dMrD__Ja-7KzjE=uMeKX8y__cx5W-OEWy2ow@mail.gmail.com
One of the examples on the SELECT page was missing a semicolon from
a listing which has the look and feel of being a psql session. This
adds the missing semicolon and also removes the newline between the
query and results to match the other examples nearby.
Backpatch to all supported branches to avoid backpatching issues on
this page.
Reported-by: tim.needham2@gmail.com
Discussion: https://postgr.es/m/169965004097.225187.12941375915673151540@wrigleys.postgresql.org
Backpatch-through: v12
Commit b7eda3e0e moved XidInMVCCSnapshot() from tqual.c into snapmgr.c,
but follow-up commit c91560def incorrectly updated this reference. We
could fix it, but as pointed out by Daniel Gustafsson, 1) the reader can
easily find the file that contains the definition of that function, e.g.
by grepping, and 2) this kind of reference is prone to going stale; so
let's just remove it.
Back-patch to all supported branches.
Reviewed by Daniel Gustafsson.
Discussion: https://postgr.es/m/CAPmGK145VdKkPBLWS2urwhgsfidbSexwY-9zCL6xSUJH%2BBTUUg%40mail.gmail.com
When computing "0 - INT64_MIN", most platforms would report an
overflow error, which is correct. However, platforms without integer
overflow builtins or 128-bit integers would fail to spot the overflow,
and incorrectly return INT64_MIN.
Back-patch to all supported branches.
Patch be me. Thanks to Jian He for initial investigation, and Laurenz
Albe and Tom Lane for review.
Discussion: https://postgr.es/m/CAEZATCUNK-AZSD0jVdgkk0N%3DNcAXBWeAEX-QU9AnJPensikmdQ%40mail.gmail.com
array_set_element() and related functions allow an array to be
enlarged by assigning to subscripts outside the current array bounds.
While these places were careful to check that the new bounds are
allowable, they neglected to consider the risk of integer overflow
in computing the new bounds. In edge cases, we could compute new
bounds that are invalid but get past the subsequent checks,
allowing bad things to happen. Memory stomps that are potentially
exploitable for arbitrary code execution are possible, and so is
disclosure of server memory.
To fix, perform the hazardous computations using overflow-detecting
arithmetic routines, which fortunately exist in all still-supported
branches.
The test cases added for this generate (after patching) errors that
mention the value of MaxArraySize, which is platform-dependent.
Rather than introduce multiple expected-files, use psql's VERBOSITY
parameter to suppress the printing of the message text. v11 psql
lacks that parameter, so omit the tests in that branch.
Our thanks to Pedro Gallegos for reporting this problem.
Security: CVE-2023-5869
transformAggregateCall() captures the datatypes of the aggregate's
arguments immediately to construct the Aggref.aggargtypes list.
This seems reasonable because the arguments have already been
transformed --- but there is an edge case where they haven't been.
Specifically, if we have an unknown-type literal in an ANY argument
position, nothing will have been done with it earlier. But if we
also have DISTINCT, then addTargetToGroupList() converts the literal
to "text" type, resulting in the aggargtypes list not matching the
actual runtime type of the argument. The end result is that the
aggregate tries to interpret a "text" value as being of type
"unknown", that is a zero-terminated C string. If the text value
contains no zero bytes, this could result in disclosure of server
memory following the text literal value.
To fix, move the collection of the aggargtypes list to the end
of transformAggregateCall(), after DISTINCT has been handled.
This requires slightly more code, but not a great deal.
Our thanks to Jingzhou Fu for reporting this problem.
Security: CVE-2023-5868
It was always false in single-user mode, in autovacuum workers, and in
background workers. This had no specifically-identified security
consequences, but non-core code or future work might make it
security-relevant. Back-patch to v11 (all supported versions).
Jelte Fennema-Nio. Reported by Jelte Fennema-Nio.
Documentation says it cannot signal "a backend owned by a superuser".
On the contrary, it could signal background workers, including the
logical replication launcher. It could signal autovacuum workers and
the autovacuum launcher. Block all that. Signaling autovacuum workers
and those two launchers doesn't stall progress beyond what one could
achieve other ways. If a cluster uses a non-core extension with a
background worker that does not auto-restart, this could create a denial
of service with respect to that background worker. A background worker
with bugs in its code for responding to terminations or cancellations
could experience those bugs at a time the pg_signal_backend member
chooses. Back-patch to v11 (all supported versions).
Reviewed by Jelte Fennema-Nio. Reported by Hemanth Sandrana and
Mahendrakar Srinivasarao.
Security: CVE-2023-5870
Fix one instance of a table cell overflow by adding a zero-width
space. The visual impact of this is minimal, but since this is
currently the only such case reported by FOP ("contents of ... exceed
the available area"), it seems worth getting rid of.
Back-patch of v14-era commit 74ff28197 into v13. It's not obvious
to me why we were not seeing this warning in v13 before, since this
file hasn't changed recently. Nonetheless, it's there now, and it's
still desirable to keep v13 and up clean on this score.
This text left one with the impression that an ON SELECT rule could
be attached to a plain table, which has not been true since commit
264c06820 (meaning the text was already misleading when written,
evidently by me in 96bd67f61). However, it didn't get really bad
until b23cd185f removed the convert-a-table-to-a-view logic, which
had made it possible for scripts that thought they were attaching
ON SELECTs to tables to still work.
Rewrite into a form that makes it clear that an ON SELECT rule
is better regarded as an implementation detail of a view.
Pre-v16, point out that adding ON SELECT to a table actually
converts it to a view.
Per bug #18178 from Joshua Uyehara. Back-patch to all supported
branches.
Discussion: https://postgr.es/m/18178-05534d7064044d2d@postgresql.org
get_explain_guc_options() crashed if a string GUC marked GUC_EXPLAIN
has a NULL boot_val. Nosing around found a couple of other places
that seemed insufficiently cautious about NULL string values, although
those are likely unreachable in practice. Add some commentary
defining the expectations for NULL values of string variables,
in hopes of forestalling future additions of more such bugs.
Xing Guo, Aleksander Alekseev, Tom Lane
Discussion: https://postgr.es/m/CACpMh+AyDx5YUpPaAgzVwC1d8zfOL4JoD-uyFDnNSa1z0EsDQQ@mail.gmail.com
This part of the documentation refers to exceptions as handled by
PL/pgSQL, and using the internal error code is confusing.
Per thinko in 66bde49d96.
Reported-by: Euler Taveira, Bruce Momjian
Discussion: https://postgr.es/m/ZUEUnLevXyW7DlCs@momjian.us
Backpatch-through: 11
4b8266415 added a precheck to pgrowlocks() to ensure the given object's
pg_class.relam is HEAP_TABLE_AM_OID, however, that check was put before
another check which was checking if the given object was a partitioned
table. Since the pg_class.relam is always InvalidOid for partitioned
tables, if pgrowlocks() was called passing a partitioned table, then the
"only heap AM is supported" error would be raised instead of the intended
error about the given object being a partitioned table.
Here we simply move the pg_class.relam check to after the check that
verifies that we are in fact working with a normal (non-partitioned)
table.
Reported-by: jian he
Discussion: https://postgr.es/m/CACJufxFaSp_WguFCf0X98951zFVX+dXFnF1mxAb-G3g1HiHOow@mail.gmail.com
Backpatch-through: 12, where 4b8266415 was introduced.
pgstatindex failed with ERRCODE_DATA_CORRUPTED, of the "can't-happen"
class XX. The other functions succeeded on an empty index; they might
have malfunctioned if the failed index build left torn I/O or other
complex state. Report an ERROR in statistics functions pgstatindex,
pgstatginindex, pgstathashindex, and pgstattuple. Report DEBUG1 and
skip all index I/O in maintenance functions brin_desummarize_range,
brin_summarize_new_values, brin_summarize_range, and
gin_clean_pending_list. Back-patch to v11 (all supported versions).
Discussion: https://postgr.es/m/20231001195309.a3@google.com
This prevents false-positive reports about "the first child of leftmost
target page is not leftmost of its level", "block %u is not leftmost"
and "left link/right link pair". They appeared if amcheck ran before
VACUUM cleaned things, after a cluster exited recovery between the
first-stage and second-stage WAL records of a deletion. Back-patch to
v11 (all supported versions).
Reviewed by Peter Geoghegan.
Discussion: https://postgr.es/m/20231005025232.c7.nmisch@google.com
Formerly, the value computed by leftmostvalue_interval() was a long
way short of the minimum possible interval value. As a result, an
index scan on a GIN index on an interval column with < or <= operators
would miss large negative interval values.
Fix by setting all fields of the leftmost interval to their minimum
values, ensuring that the result is less than any other possible
interval. Since this only affects index searches, no index rebuild is
necessary.
Back-patch to all supported branches.
Dean Rasheed, reviewed by Heikki Linnakangas.
Discussion: https://postgr.es/m/CAEZATCV80%2BgOfF8ehNUUfaKBZgZMDfCfL-g1HhWGb6kC3rpDfw%40mail.gmail.com
When looping around after finding that the set-returning function
returned zero rows for the current input tuple, ExecProjectSet
neglected to reset either of the two memory contexts it's
responsible for cleaning out. Typically this wouldn't cause much
problem, because once the SRF does return at least one row, the
contexts would get reset on the next call. However, if the SRF
returns no rows for many input tuples in succession, quite a lot
of memory could be transiently consumed.
To fix, make sure we reset both contexts while looping around.
Per bug #18172 from Sergei Kornilov. Back-patch to all supported
branches.
Discussion: https://postgr.es/m/18172-9b8c5fc1d676ded3@postgresql.org
Debian recently decided to split out a bunch of "obsolete" timezone
names into a new tzdata-legacy package, which isn't installed by
default. One of these zone names is Pacific/Enderbury, and that
breaks our regression tests (on --with-system-tzdata builds)
because our default timezone abbreviations list defines PHOT as
Pacific/Enderbury.
Pacific/Enderbury got renamed to Pacific/Kanton in tzdata 2021b,
so that in distros that still have this entry it's just a symlink
to Pacific/Kanton anyway. So one answer would be to redefine PHOT
as Pacific/Kanton. However, then things would fail if the
installed tzdata predates 2021b, which is recent enough that that
seems like a real problem.
Instead, let's just remove PHOT from the default list. That seems
likely to affect nobody in the real world, because (a) it was an
abbreviation that the tzdb crew made up in the first place, with
no evidence of real-world usage, and (b) the total human population
of the Phoenix Islands is less than two dozen persons, per Wikipedia.
If anyone does use this zone abbreviation they can easily put it back
via a custom abbreviations file.
We'll keep PHOT in the Pacific.txt reference file, but change it
to Pacific/Kanton there, as that definition seems more likely to
be useful to future readers of that file.
Per report from Victor Wagner. Back-patch to all supported
branches.
Discussion: https://postgr.es/m/20231027152049.4b5c8044@wagner.wagner.home
As far as I can see, ecpg has no notion of a "default" open
connection. You can do "CONNECT TO DEFAULT" but that just specifies
letting libpq use all its default connection parameters --- the
resulting connection is not special subsequently. In particular,
SET CONNECTION = DEFAULT and DISCONNECT DEFAULT simply act on a
connection named DEFAULT, if you've made one; they do not have
special lookup rules. But the documentation of these commands
makes it look like they do.
Simplest fix, I think, is just to remove the paras suggesting that
DEFAULT is special here.
Also, SET CONNECTION *does* have one special lookup rule, which
is that it recognizes CURRENT as an alias for the currently selected
connection. SET CONNECTION = CURRENT is a no-op, so it's pretty
useless, but nonetheless it does something different from selecting
a connection by name; so we'd better document it.
Per report from Sylvain Frandaz. Back-patch to all supported
versions.
Discussion: https://postgr.es/m/169824721149.1769274.1553568436817652238@wrigleys.postgresql.org
While back-patching f90b4a84, I missed that branches before
REL_14_STABLE did some (accidental?) type punning in a function
parameter, and failed to adjust these two branches accordingly. That
didn't seem to cause a problem for newer LLVM versions or non-debug
builds, but older debug builds would fail a type cross-check assertion.
Fix by supplying the correct function argument type. In REL_14_STABLE
the same change was made by commit df99ddc7.
Per build farm animal xenodermus, which runs a debug build of LLVM 6
with jit_above_cost=0.
Discussion: https://postgr.es/m/CA%2BhUKGLQ38rgZ3bvNHXPRjsWFAg3pa%3Dtnpeq0osa%2B%3DmiFD5jAw%40mail.gmail.com
When scanning build farm results, it's useful to be able to see which
version is in use. For the Meson build system, this information was
already displayed.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/4022690.1697852728%40sss.pgh.pa.us
This avoids a compiler bug occurring in AIX's xlc, even in pretty
late-model revisions. Buildfarm testing has now confirmed that
only 64-bit xlc is affected. Although we are contemplating
dropping support for xlc in v17, it's still supported in the
back branches, so we need this fix.
Back-patch of code changes from HEAD commit 19fa97731.
(The test cases were already back-patched, in 4a427b82c et al.)
Discussion: https://postgr.es/m/CA+hUKGK=DOC+hE-62FKfZy=Ybt5uLkrg3zCZD-jFykM-iPn8yw@mail.gmail.com
This doco said that use of => as an operator "is deprecated".
It's been fully disallowed since 865f14a2d back in 9.5, but
evidently that commit missed updating this statement.
Do so now.
When processing a match tag, check to see if the claimed "off"
is more than the distance back to the output buffer start.
If it is, then the data is corrupt, and what's more we would
fetch from outside the buffer boundaries and potentially incur
a SIGSEGV. (Although the odds of that seem relatively low, given
that "off" can't be more than 4K.)
Back-patch to v13; before that, this function wasn't really
trying to protect against bad data.
Report and fix by Flavien Guedez.
Discussion: https://postgr.es/m/01fc0593-e31e-463d-902c-dd43174acee2@oopacity.net
Remove use of LLVMGetElementType() and provide the type of all pointers
to LLVMBuildXXX() functions when emitting IR, as required by modern LLVM
versions[1].
* For LLVM <= 14, we'll still use the old LLVMBuildXXX() functions.
* For LLVM == 15, we'll continue to do the same, explicitly opting
out of opaque pointer mode.
* For LLVM >= 16, we'll use the new LLVMBuildXXX2() functions that take
the extra type argument.
The difference is hidden behind some new IR emitting wrapper functions
l_load(), l_gep(), l_call() etc. The change is mostly mechanical,
except that at each site the correct type had to be provided.
In some places we needed to do some extra work to get functions types,
including some new wrappers for C++ APIs that are not yet exposed by in
LLVM's C API, and some new "example" functions in llvmjit_types.c
because it's no longer possible to start from the function pointer type
and ask for the function type.
Back-patch to 12, because it's a little tricker in 11 and we agreed not
to put the latest LLVM support into the upcoming final release of 11.
[1] https://llvm.org/docs/OpaquePointers.html
Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com>
Reviewed-by: Ronan Dunklau <ronan.dunklau@aiven.io>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CA%2BhUKGKNX_%3Df%2B1C4r06WETKTq0G4Z_7q4L4Fxn5WWpMycDj9Fw%40mail.gmail.com
This commit (c290e79cf0) was originally back-patched to v15.
Commit 97550c0711 added a new use of STDERR_FILENO, and it was
back-patched all the way to v11, thus breaking MSVC builds for v11
through v14. Since STDERR_FILENO is now needed on older versions,
let's back-patch c290e79cf0 down to v11, too.
Here follows the original commit message describing the change:
Because they are not available we've used _fileno(stdin) in some places, but
that doesn't reliably work, because stdin might be closed. This is the
prerequisite of the subsequent commit, fixing a failure introduced in
76e38b37a5.
Author: Andres Freund <andres@anarazel.de>
Reported-By: Sandeep Thakkar <sandeep.thakkar@enterprisedb.com>
Message-Id: 20220520164558.ozb7lm6unakqzezi@alap3.anarazel.de (on pgsql-packagers)
Discussion: https://postgr.es/m/20231017164517.GA613565%40nathanxps13
Backpatch-through: 11
Per code coverage reports, we had zero regression test coverage
of these functions. That came back to bite us, as apparently
that's allowed us to miss discovering misbehavior of this code
with AIX's xlc compiler. Install relevant portions of the
test cases added in 97957fdba, 2f0472030, 19fa97731.
(Assuming the expected outcome that the xlc problem does appear
in back branches, a code fix will follow.)
Discussion: https://postgr.es/m/CA+hUKGK=DOC+hE-62FKfZy=Ybt5uLkrg3zCZD-jFykM-iPn8yw@mail.gmail.com
The SIGTERM handler for the startup process immediately calls
proc_exit() for the duration of the restore_command, i.e., a call
to system(). This system() call forks a new process to execute the
shell command, and this child process inherits the parent's signal
handlers. If both the parent and child processes receive SIGTERM,
both will attempt to call proc_exit(). This can end badly. For
example, both processes will try to remove themselves from the
PGPROC shared array.
To fix this problem, this commit adds a check in
StartupProcShutdownHandler() to see whether MyProcPid == getpid().
If they match, this is the parent process, and we can proc_exit()
like before. If they do not match, this is a child process, and we
just emit a message to STDERR (in a signal safe manner) and
_exit(), thereby skipping any problematic exit callbacks.
This commit also adds checks in proc_exit(), ProcKill(), and
AuxiliaryProcKill() that verify they are not being called within
such child processes.
Suggested-by: Andres Freund
Reviewed-by: Thomas Munro, Andres Freund
Discussion: https://postgr.es/m/Y9nGDSgIm83FHcad%40paquier.xyz
Discussion: https://postgr.es/m/20230223231503.GA743455%40nathanxps13
Backpatch-through: 11
Dropping a temp table could entail TOAST table access to clean out
toasted catalog entries, such as large pg_constraint.conbin strings
for complex CHECK constraints. If we did that via ON COMMIT DROP,
we triggered the assertion in init_toast_snapshot(), because
there was no provision for setting up a snapshot for the drop
actions. Fix that.
(I assume here that the adjacent truncation actions for ON COMMIT
DELETE ROWS don't have a similar problem: it doesn't seem like
nontransactional truncations would need to touch any toasted fields.
If that proves wrong, we could refactor a bit to have the same
snapshot acquisition cover that too.)
The test case added here does not fail before v15, because that
assertion was added in 277692220 which was not back-patched.
However, the race condition the assertion warns of surely
exists further back, so back-patch to all supported branches.
Per report from Richard Guo.
Discussion: https://postgr.es/m/CAMbWs4-x26=_QxxgdJyNbiCDzvtr2WV5ZDso_v-CukKEe6cBZw@mail.gmail.com
Some of our src/bin tools read the control file without any kind of
interlocking against concurrent writes from the server. At least ext4
and ntfs can expose partially modified contents when you do that.
For now, we'll try to tolerate this by retrying up to 10 times if the
checksum doesn't match, until we get two reads in a row with the same
bad checksum. This is not guaranteed to reach the right conclusion, but
it seems very likely to. Thanks to Tom Lane for this suggestion.
Various ideas for interlocking or atomicity were considered too
complicated, unportable or expensive given the lack of field reports,
but remain open for future reconsideration.
Back-patch as far as 12. It doesn't seem like a good idea to put a
heuristic change for a very rare problem into the final release of 11.
Reviewed-by: Anton A. Melnikov <aamelnikov@inbox.ru>
Reviewed-by: David Steele <david@pgmasters.net>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/20221123014224.xisi44byq3cf5psi%40awork3.anarazel.de
Commit dc7d70ea added functions that read the control file, but didn't
acquire ControlFileLock. With unlucky timing, file systems that have
weak interlocking like ext4 and ntfs could expose partially overwritten
contents, and the checksum would fail.
Back-patch to all supported releases.
Reviewed-by: David Steele <david@pgmasters.net>
Reviewed-by: Anton A. Melnikov <aamelnikov@inbox.ru>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/20221123014224.xisi44byq3cf5psi%40awork3.anarazel.de
Under interval_ops, some equal values are distinguishable. One such
pair is '24:00:00' and '1 day'. With that being so, btequalimage()
breaches the documented contract for the "equalimage" btree support
function. This can cause incorrect results from index-only scans.
Users should REINDEX any btree indexes having interval-type columns.
After updating, pg_amcheck will report an error for almost all such
indexes. This fix makes interval_ops simply omit the support function,
like numeric_ops does. Back-pack to v13, where btequalimage() first
appeared. In back branches, for the benefit of old catalog content,
btequalimage() code will return false for type "interval". Going
forward, back-branch initdb will include the catalog change.
Reviewed by Peter Geoghegan.
Discussion: https://postgr.es/m/20231011013317.22.nmisch@google.com
Tom Lane
Bruce Momjian
Daniel Gustafsson
Etsuro Fujita
David Rowley
Dean Rasheed
Noah Misch
Peter Eisentraut
Michael Paquier
Thomas Munro
Nathan Bossart