The documentation says plainly that \password acts on "the current user"
by default.  What it actually acted on, or tried to, was the username
used to log into the current session.  This is not the same thing if
one has since done SET ROLE or SET SESSION AUTHENTICATION.  Aside from
the possible surprise factor, it's quite likely that the current role
doesn't have permissions to set the password of the original role.

To fix, use "SELECT CURRENT_USER" to get the role name to act on.
(This syntax works with servers at least back to 7.0.)  Also, in
hopes of reducing confusion, include the role name that will be
acted on in the password prompt.

The discrepancy from the documentation makes this a bug, so
back-patch to all supported branches.

Patch by me; thanks to Nathan Bossart for review.

Discussion: https://postgr.es/m/747443.1635536754@sss.pgh.pa.us

pg_stat_get_slru() in pgstatfuncs.c would point to one element after the
end of the array PgStat_SLRUStats when finishing to scan its entries.
This had no direct consequences as no data from the extra memory area
was read, but static analyzers would rightfully complain here.  So let's
be clean.

While on it, this adds one regression test in the area reserved for
system views.

Reported-by: Alexander Kozhemyakin, via AddressSanitizer
Author: Kyotaro Horiguchi
Discussion: https://postgr.es/m/17280-37da556e86032070@postgresql.org
Backpatch-through: 13

Buildfarm members kittiwake and tadarida have witnessed errors at this
site.  The site discarded key facts.  Back-patch to v10 (all supported
versions).

Reviewed by Michael Paquier and Tom Lane.

Discussion: https://postgr.es/m/20211107013157.GB790288@rfd.leadboat.com

Commit 27838981 mistakenly reduced the lock level from exclusive to
shared that is acquired to set PGPROC->statusFlags; this was reverted
by dcfff74f, but failed to do so in one spot.  Fix it.

Backpatch to 14.

Noted by Andres Freund.

Discussion: https://postgr.es/m/20211111020724.ggsfhcq3krq5r4hb@alap3.anarazel.de

PostgreSQL 13 and newer versions are directly impacted by that through
the SQL function normalize(), which would cause a call of this function
to write one byte past its allocation if using in input an empty
string after recomposing the string with NFC and NFKC.  Older versions
(v10~v12) are not directly affected by this problem as the only code
path using normalization is SASLprep in SCRAM authentication that
forbids the case of an empty string, but let's make the code more robust
anyway there so as any out-of-core callers of this function are covered.

The solution chosen to fix this issue is simple, with the addition of a
fast-exit path if the decomposed string is found as empty.  This would
only happen for an empty string as at its lowest level a codepoint would
be decomposed as itself if it has no entry in the decomposition table or
if it has a decomposition size of 0.

Some tests are added to cover this issue in v13~.  Note that an empty
string has always been considered as normalized (grammar "IS NF[K]{C,D}
NORMALIZED", through the SQL function is_normalized()) for all the
operations allowed (NFC, NFD, NFKC and NFKD) since this feature has been
introduced as of 2991ac5f.  This behavior is unchanged but some tests are
added in v13~ to check after that.

I have also checked "make normalization-check" in src/common/unicode/,
while on it (works in 13~, and breaks in older stable branches
independently of this commit).

The release notes should just mention this commit for v13~.

Reported-by: Matthijs van der Vleuten
Discussion: https://postgr.es/m/17277-0c527a373794e802@postgresql.org
Backpatch-through: 10

clang-12 has introduced -Wcompound-token-split-by-macro, that is causing
a large amount of warnings when building PL/Perl because of its
interactions with upstream Perl.  This commit adds one -Wno to CFLAGS at
./configure time if the flag is supported by the compiler to silence all
those warnings.

Upstream perl has fixed this issue, but it is going to take some time
before this is spread across the buildfarm, and we have noticed that
some animals would be useful with an extra -Werror to help with the
detection of incorrect placeholders (see b0cf544), dangomushi being
one.

Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/YYr3qYa/R3Gw+Sbg@paquier.xyz
Backpatch-through: 10

protocol.sgml documented the layout for Type messages, but completely
dropped the ball otherwise, failing to explain what they are, when
they are sent, or what they're good for.  While at it, do a little
copy-editing on the description of Relation messages.

In passing, adjust the comment for apply_handle_type() to make it
clearer that we choose not to do anything when receiving a Type
message, not that we think it has no use whatsoever.

Per question from Stefen Hillman.

Discussion: https://postgr.es/m/CAPgW8pMknK5pup6=T4a_UG=Cz80Rgp=KONqJmTdHfaZb0RvnFg@mail.gmail.com

We've seen intermittent failures in this test on slower buildfarm
machines, which I think can be explained by assuming that autovacuum
emitted some additional WAL.  Disable autovacuum to stabilize it.

In passing, use stringwise not numeric comparison to compare
WAL file names.  Doesn't matter at present, but they are
hex strings not decimal ...

Discussion: https://postgr.es/m/1372189.1636499287@sss.pgh.pa.us

Security: CVE-2021-23214, CVE-2021-23222

libpq collects up to a bufferload of data whenever it reads data from
the socket.  When SSL or GSS encryption is requested during startup,
any additional data received with the server's yes-or-no reply
remained in the buffer, and would be treated as already-decrypted data
once the encryption handshake completed.  Thus, a man-in-the-middle
with the ability to inject data into the TCP connection could stuff
some cleartext data into the start of a supposedly encryption-protected
database session.

This could probably be abused to inject faked responses to the
client's first few queries, although other details of libpq's behavior
make that harder than it sounds.  A different line of attack is to
exfiltrate the client's password, or other sensitive data that might
be sent early in the session.  That has been shown to be possible with
a server vulnerable to CVE-2021-23214.

To fix, throw a protocol-violation error if the internal buffer
is not empty after the encryption handshake.

Our thanks to Jacob Champion for reporting this problem.

Security: CVE-2021-23222

The server collects up to a bufferload of data whenever it reads data
from the client socket.  When SSL or GSS encryption is requested
during startup, any additional data received with the initial
request message remained in the buffer, and would be treated as
already-decrypted data once the encryption handshake completed.
Thus, a man-in-the-middle with the ability to inject data into the
TCP connection could stuff some cleartext data into the start of
a supposedly encryption-protected database session.

This could be abused to send faked SQL commands to the server,
although that would only work if the server did not demand any
authentication data.  (However, a server relying on SSL certificate
authentication might well not do so.)

To fix, throw a protocol-violation error if the internal buffer
is not empty after the encryption handshake.

Our thanks to Jacob Champion for reporting this problem.

Security: CVE-2021-23214

Source-Git-URL: git://git.postgresql.org/git/pgtranslation/messages.git
Source-Git-Hash: f54c1d7c2c97bb2a238a149e407023a9bc007b06

In v14, because we don't have a field in RestrictInfo to cache both the
left and right type's hash equality operator, we just restrict the scope
of Memoize to only when the left and right types of a RestrictInfo are the
same.

In master we add another field to RestrictInfo and cache both hash
equality operators.

Reported-by: Jaime Casanova
Author: David Rowley
Discussion: https://postgr.es/m/20210929185544.GB24346%40ahch-to
Backpatch-through: 14

Currently, lastOverflowedXid is never reset.  It's just adjusted on new
transactions known to be overflowed.  But if there are no overflowed
transactions for a long time, snapshots could be mistakenly marked as
suboverflowed due to wraparound.

This commit fixes this issue by resetting lastOverflowedXid when needed
altogether with KnownAssignedXids.

Backpatch to all supported versions.

Reported-by: Stan Hu
Discussion: https://postgr.es/m/CAMBWrQ%3DFp5UAsU_nATY7EMY7NHczG4-DTDU%3DmCvBQZAQ6wa2xQ%40mail.gmail.com
Author: Kyotaro Horiguchi, Alexander Korotkov
Reviewed-by: Stan Hu, Simon Riggs, Nikolay Samokhvalov, Andrey Borodin, Dmitry Dolgov

Add latest commits.  Fix some typos and infelicitous wording
(thanks to Justin Pryzby for proof-reading).

When calculating distance between float4/float8 values, we need to be a
bit more careful about NaN values in order not to trigger assert. We
consider NaN values to be equal (distace 0.0) and in infinite distance
from all other values.

On builds without asserts, this issue is mostly harmless - the ranges
may be merged in less efficient order, but the index is still correct.

Per report from Andreas Seltenreich. Backpatch to 14, where this new
BRIN opclass was introduced.

Reported-by: Andreas Seltenreich
Discussion: https://postgr.es/m/87r1bw9ukm.fsf@credativ.de

As usual, the release notes for other branches will be made by cutting
these down, but put them up for community review first.

Also as usual for a .1 release, there are some entries here that
are not really relevant for v14 because they already appeared in 14.0.
Those'll be removed later.

When a role being dropped contains is referenced by catalog objects that
are concurrently also being dropped, a crash can result while trying to
construct the string that describes the objects.  Suppress that by
ignoring objects whose descriptions are returned as NULL.

The majority of relevant codesites were already cautious about this
already; we had just missed a couple.

This is an old bug, so backpatch all the way back.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/17126-21887f04508cb5c8@postgresql.org

... so mention that in appropriate places of the libpq docs.

Backpatch to 14.
Reported-by: RekGRpth <rekgrpth@gmail.com>
Discussion: https://postgr.es/m/17235-53bb38fc5be593dc@postgresql.org

Previous commit added a test to 'largeobject', but neglected the
alternative expected output file 'largeobject_1.source'. Per failure
on buildfarm animal 'hamerkop'.

Discussion: https://www.postgresql.org/message-id/DBA08346-9962-4706-92D1-230EE5201C10@yesql.se

If lo_export() fails to open the target file or to write to it, it leaks
the created LargeObjectDesc and its snapshot in the top-transaction
context and resource owner. That's pretty harmless, it's a small leak
after all, but it gives the user a "Snapshot reference leak" warning.

Fix by using a short-lived memory context and no resource owner for
transient LargeObjectDescs that are opened and closed within one function
call. The leak is easiest to reproduce with lo_export() on a directory
that doesn't exist, but in principle the other lo_* functions could also
fail.

Backpatch to all supported versions.

Reported-by: Andrew B
Reviewed-by: Alvaro Herrera
Discussion: https://www.postgresql.org/message-id/32bf767a-2d65-71c4-f170-122f416bab7e@iki.fi

Commit b4af70cb inverted the return value of the function
parallel_processing_is_safe(), but missed the amvacuumcleanup test.
Index AMs that don't support parallel cleanup at all were affected.

The practical consequences of this bug were not very serious.  Hash
indexes are affected, but since they just return the number of blocks
during hashvacuumcleanup anyway, it can't have had much impact.

Author: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/CAD21AoA-Em+aeVPmBbL_s1V-ghsJQSxYL-i3JP8nTfPiD1wjKw@mail.gmail.com
Backpatch: 14-, where commit b4af70cb appears.

Commit b4af70cb, which simplified state managed by VACUUM, performed
refactoring of parallel VACUUM in passing.  Confusion about the exact
details of the tasks that the leader process is responsible for led to
code that made it possible for parallel VACUUM to miss a subset of the
table's indexes entirely.  Specifically, indexes that fell under the
min_parallel_index_scan_size size cutoff were missed.  These indexes are
supposed to be vacuumed by the leader (alongside any parallel unsafe
indexes), but weren't vacuumed at all.  Affected indexes could easily
end up with duplicate heap TIDs, once heap TIDs were recycled for new
heap tuples.  This had generic symptoms that might be seen with almost
any index corruption involving structural inconsistencies between an
index and its table.

To fix, make sure that the parallel VACUUM leader process performs any
required index vacuuming for indexes that happen to be below the size
cutoff.  Also document the design of parallel VACUUM with these
below-size-cutoff indexes.

It's unclear how many users might be affected by this bug.  There had to
be at least three indexes on the table to hit the bug: a smaller index,
plus at least two additional indexes that themselves exceed the size
cutoff.  Cases with just one additional index would not run into
trouble, since the parallel VACUUM cost model requires two
larger-than-cutoff indexes on the table to apply any parallel
processing.  Note also that autovacuum was not affected, since it never
uses parallel processing.

Test case based on tests from a larger patch to test parallel VACUUM by
Masahiko Sawada.

Many thanks to Kamigishi Rei for her invaluable help with tracking this
problem down.

Author: Peter Geoghegan <pg@bowt.ie>
Author: Masahiko Sawada <sawada.mshk@gmail.com>
Reported-By: Kamigishi Rei <iijima.yun@koumakan.jp>
Reported-By: Andrew Gierth <andrew@tao11.riddles.org.uk>
Diagnosed-By: Andres Freund <andres@anarazel.de>
Bug: #17245
Discussion: https://postgr.es/m/17245-ddf06aaf85735f36@postgresql.org
Discussion: https://postgr.es/m/20211030023740.qbnsl2xaoh2grq3d@alap3.anarazel.de
Backpatch: 14-, where the refactoring commit appears.

This undoes a mistake in 1ec7679f: domainval and domainnull were
meant to live across loop iterations, but they were incorrectly
moved inside the loop.  The effect was only to emit useless extra
EEOP_MAKE_READONLY steps, so it's not a big deal; nonetheless,
back-patch to v13 where the mistake was introduced.

Ranier Vilela

Discussion: https://postgr.es/m/CAEudQAqXuhbkaAp-sGH6dR6Nsq7v28_0TPexHOm6FiDYqwQD-w@mail.gmail.com

As in commits 6301c3ada and e9d9ba2a4, avoid doing repetitive
list_delete_first() operations, since that would be expensive when
there are many files waiting to be unlinked.  This is a slightly
larger change than in those cases.  We have to keep the list state
valid for calls to AbsorbSyncRequests(), so it's necessary to invent a
"canceled" field instead of immediately deleting PendingUnlinkEntry
entries.  Also, because we might not be able to process all the
entries, we need a new list primitive list_delete_first_n().

list_delete_first_n() is almost list_copy_tail(), but it modifies the
input List instead of making a new copy.  I found a couple of existing
uses of the latter that could profitably use the new function.  (There
might be more, but the other callers look like they probably shouldn't
overwrite the input List.)

As before, back-patch to v13.

Discussion: https://postgr.es/m/CD2F0E7F-9822-45EC-A411-AE56F14DEA9F@amazon.com

In the same spirit as 6301c3ada, fix some more places where we were
using list_delete_first() in a loop and thereby risking O(N^2)
behavior.  It's not clear that the lists manipulated in these spots
can get long enough to be really problematic ... but it's not clear
that they can't, either, and the fixes are simple enough.

As before, back-patch to v13.

Discussion: https://postgr.es/m/CD2F0E7F-9822-45EC-A411-AE56F14DEA9F@amazon.com

Failing to do so results in inability of logical decoding to process the
WAL stream.  Handle it by doing nothing.

Backpatch all the way back.
Reported-by: Petr Jelínek <petr.jelinek@enterprisedb.com>

The opclass parameter Datums from the old index are fetched in the same
way as for predicates and expressions, by grabbing them directly from
the system catalogs.  They are then copied into the new IndexInfo that
will be used for the creation of the new copy.

This caused the new index to be rebuilt with default parameters rather
than the ones pre-defined by a user.  The only way to get back a new
index with correct opclass parameters would be to recreate a new index
from scratch.

The issue has been introduced by 911e7020.

Author: Michael Paquier
Reviewed-by: Zhihong Yu
Discussion: https://postgr.es/m/YX0CG/QpLXcPr8HJ@paquier.xyz
Backpatch-through: 13

Windows fails on a request to read() more than INT_MAX bytes,
and perhaps other platforms could have similar issues.  Let's
adjust this code to read at most 1GB per call.

(One would not have thought the file could get that big, but now
we have a field report of trouble, so it can.  We likely ought to
add some mechanism to limit the size of the query-texts file
separately from the size of the hash table.  That is not this
patch, though.)

Per bug #17254 from Yusuke Egashira.  It's been like this for
awhile, so back-patch to all supported branches.

Discussion: https://postgr.es/m/17254-a926c89dc03375c2@postgresql.org

When replaying a transaction that held many exclusive locks on the
primary, a standby server's startup process would expend O(N^2)
effort on manipulating the list of locks.  This code was fine when
written, but commit 1cff1b95 made repetitive list_delete_first()
calls inefficient, as explained in its commit message.  Fix by just
iterating the list normally, and releasing storage only when done.
(This'd be inadequate if we needed to recover from an error occurring
partway through; but we don't.)

Back-patch to v13 where 1cff1b95 came in.

Nathan Bossart

Discussion: https://postgr.es/m/CD2F0E7F-9822-45EC-A411-AE56F14DEA9F@amazon.com

Commit d168b666, which overhauled index deletion, added a
pg_unreachable() to the end of a sort comparator used when sorting heap
TIDs from an index page.  This allows the compiler to apply
optimizations that assume that the heap TIDs from the index AM must
always be unique.

That doesn't seem like a good idea now, given recent reports of
corruption involving duplicate TIDs in indexes on Postgres 14.  Demote
to an assertion, just in case.

Backpatch: 14-, where index deletion was overhauled.

DST law changes in Fiji, Jordan, Palestine, and Samoa.  Historical
corrections for Barbados, Cook Islands, Guyana, Niue, Portugal, and
Tonga.

Also, the Pacific/Enderbury zone has been renamed to Pacific/Kanton.
The following zones have been merged into nearby, more-populous zones
whose clocks have agreed since 1970: Africa/Accra, America/Atikokan,
America/Blanc-Sablon, America/Creston, America/Curacao,
America/Nassau, America/Port_of_Spain, Antarctica/DumontDUrville,
and Antarctica/Syowa.

Commits fdd965d07 and 3cd9c3b92 tested CREATE INDEX CONCURRENTLY by
launching two separate pgbench runs concurrently.  This was needed so
that only a single client thread would run CREATE INDEX CONCURRENTLY,
avoiding deadlock between two CICs.  However, there's a better way,
which is to use an advisory lock to prevent concurrent CICs.  That's
better in part because the test code is shorter and more readable, but
mostly because it automatically scales things to launch an appropriate
number of CICs relative to the number of INSERT transactions.
As committed, typically half to three-quarters of the CIC transactions
were pointless because the INSERT transactions had already stopped.

In passing, remove background_pgbench, which was added to support
these tests and isn't needed anymore.  We can always put it back
if we find a use for it later.

Back-patch to v12; older pgbench versions lack the
conditional-execution features needed for this method.

Tom Lane and Andrey Borodin

Discussion: https://postgr.es/m/139687.1635277318@sss.pgh.pa.us

Reported-by: Anton Voloshin
Discussion: https://postgr.es/m/15a86d4e-a237-1acd-18a2-fd69730f1ab9@postgrespro.ru
Backpatch-through: 10

Oversight in commit a5213adf.

Backpatch: 13-, just like commit a5213adf.

Add more defensive checks around posting list split code.  These should
detect corruption involving duplicate table TIDs earlier and more
reliably than any existing check.

Follow up to commit 8f72bbac.

Discussion: https://postgr.es/m/CAH2-WzkrSY_kjyd1_M5xJK1uM0govJXMxPn8JUSvwcUOiHuWVw@mail.gmail.com
Backpatch: 13-, where nbtree deduplication was introduced.

Make this more clear both in the help message and docs.

Reviewed-By: Michael Paquier
Backpatch-through: 9.6
Discussion: https://postgr.es/m/CABUevEw6Je0WUFTLhPKOk4+BoBuDrE-fKw3N4ckqgDBMFu4paA@mail.gmail.com

The previous coding relied on the memory for the slots being zeroed
elsewhere, which while it was true in this case is not an contract
which is guaranteed to hold.  Explicitly clear the tts_isnull array
to ensure that the slots are filled from a known state.

Backpatch to v14 where the catalog multi-inserts were introduced.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CAJ7c6TP0AowkUgNL6zcAK-s5HYsVHVBRWfu69FRubPpfwZGM9A@mail.gmail.com
Backpatch-through: 14