When stuffing a plan from the plancache into a Portal, one is
not supposed to risk throwing an error between GetCachedPlan and
PortalDefineQuery; if that happens, the plan refcount incremented
by GetCachedPlan will be leaked. I managed to break this rule
while refactoring code in 9dbf2b7d7. There is no visible
consequence other than some memory leakage, and since nobody is
very likely to trigger the relevant error conditions many times
in a row, it's not surprising we haven't noticed. Nonetheless,
it's a bug, so rearrange the order of operations to remove the
hazard.
Noted on the way to looking for a better fix for bug #17053.
This mistake is pretty old, so back-patch to all supported
branches.
Since commit c24dcd0cfd, we have been using pg_pread() to read the WAL
file, which doesn't change the seek position (unless we fall back to
the implementation in src/port/pread.c). Update comment accordingly.
Backpatch-through: 12, where we started to use pg_pread()
TestLib::perl2host can take a file argument as well as a directory
argument, so that code becomes substantially simpler. Also add comments
on why we're using forward slashes, and why we're setting
PERL_BADLANG=0.
Discussion: https://postgr.es/m/e9947bcd-20ee-027c-f0fe-01f736b7e345@dunslane.net
During decoding for speculative inserts, we were relying for cleaning
toast hash on confirmation records or next change records. But that
could lead to multiple problems (a) memory leak if there is neither a
confirmation record nor any other record after toast insertion for a
speculative insert in the transaction, (b) error and assertion failures
if the next operation is not an insert/update on the same table.
The fix is to start queuing spec abort change and clean up toast hash
and change record during its processing. Currently, we are queuing the
spec aborts for both toast and main table even though we perform cleanup
while processing the main table's spec abort record. Later, if we have a
way to distinguish between the spec abort record of toast and the main
table, we can avoid queuing the change for spec aborts of toast tables.
Reported-by: Ashutosh Bapat
Author: Dilip Kumar
Reviewed-by: Amit Kapila
Backpatch-through: 9.6, where it was introduced
Discussion: https://postgr.es/m/CAExHW5sPKF-Oovx_qZe4p5oM6Dvof7_P+XgsNAViug15Fm99jA@mail.gmail.com
This should have been updated in d2d8a229b, but it was overlooked.
According to 31a877f18 which added it, this file is meant to show the
results you get under default_transaction_isolation = serializable.
We've largely lost track of that goal in other isolation tests, but
as long as we've got this one, it should be right.
Noted while fooling about with the isolationtester.
Recent glibc versions have made mktime() fail if tm_isdst is
inconsistent with the prevailing timezone; in particular it fails for
tm_isdst = 1 when the zone is UTC. (This seems wildly inconsistent
with the POSIX-mandated treatment of "incorrect" values for the other
fields of struct tm, so if you ask me it's a bug, but I bet they'll
say it's intentional.) This has been observed to cause cosmetic
problems when pg_restore'ing an archive created in a different
timezone.
To fix, do mktime() using the field values from the archive, and if
that fails try again with tm_isdst = -1. This will give a result
that's off by the UTC-offset difference from the original zone, but
that was true before, too. It's not terribly critical since we don't
do anything with the result except possibly print it. (Someday we
should flush this entire bit of logic and record a standard-format
timestamp in the archive instead. That's not okay for a back-patched
bug fix, though.)
Also, guard our only other use of mktime() by having initdb's
build_time_t() set tm_isdst = -1 not 0. This case could only have
an issue in zones that are DST year-round; but I think some do exist,
or could in future.
Per report from Wells Oliver. Back-patch to all supported
versions, since any of them might need to run with a newer glibc.
Discussion: https://postgr.es/m/CAOC+FBWDhDHO7G-i1_n_hjRzCnUeFO+H-Czi1y10mFhRWpBrew@mail.gmail.com
Translate path slashes on target directory path. This was confusing old
branches, but is applied to all branches for the sake of uniformity.
Perl is perfectly able to understand paths with forward slashes.
Along the way, restore the previous archive_wait query, for the sake of
uniformity with other tests, per gripe from Tom Lane.
This is similar to the work done in 8279f68 for TestLib.pm, where
environment variables set may cause unwanted failures if using a
temporary installation with pg_regress. The list of variables reset is
adjusted in each stable branch depending on what is supported.
Comments are added to remember that the lists in TestLib.pm and
pg_regress.c had better be kept in sync.
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/YMNR9GYDn+fHlMta@paquier.xyz
Backpatch-through: 9.6
Several TAP tests use poll_query_until() to wait for the postmaster
to restart. They were checking to see if a trivial query
(e.g. "SELECT 1") succeeds. However, that's problematic in the wake
of commit 11e9caff8, because now that we feed said query to psql
via stdin, we risk IPC::Run whining about a SIGPIPE failure if psql
quits before reading the query. Hence, we can't use a nonempty
query in cases where we need to wait for connection failures to
stop happening.
Per the precedent of commits c757a3da0 and 6d41dd045, we can pass
"undef" as the query in such cases to ensure that IPC::Run has
nothing to write. However, then we have to say that the expected
output is empty, and this exposes a deficiency in poll_query_until:
if psql fails altogether and returns empty stdout, poll_query_until
will treat that as a success! That's because, contrary to its
documentation, it makes no actual check for psql failure, looking
neither at the exit status nor at stderr.
To fix that, adjust poll_query_until to insist on empty stderr as
well as a stdout match. (I experimented with checking exit status
instead, but it seems that psql often does exit(1) in cases that we
need to consider successes. That might be something to fix someday,
but it would be a non-back-patchable behavior change.)
Back-patch to v10. The test cases needing this exist only as far
back as v11, but it seems wise to keep poll_query_until's behavior
the same in v10, in case we back-patch another such test case in
future. (9.6 does not currently need this change, because in that
branch poll_query_until can't be told to accept empty stdout as
a success case.)
Per assorted buildfarm failures, mostly on hoverfly.
Discussion: https://postgr.es/m/CAA4eK1+zM6L4QSA1XMvXY_qqWwdUmqkOS1+hWvL8QcYEBGA1Uw@mail.gmail.com
Previously, a zero value for the relfilenode resulted in
a confusing error message about "unexpected duplicate".
This function returns NULL for other invalid relfilenode
values, so zero should be treated likewise.
It's been like this all along, so back-patch to all supported
branches.
Justin Pryzby
Discussion: https://postgr.es/m/20210612023324.GT16435@telsasoft.com
Using an Assert to check the validity of incoming messages is an
extremely poor decision. In a debug build, it should not be that easy
for a broken or malicious remote client to crash the logrep worker.
The consequences could be even worse in non-debug builds, which will
fail to make such checks at all, leading to who-knows-what misbehavior.
Hence, promote every Assert that could possibly be triggered by wrong
or out-of-order replication messages to a full test-and-ereport.
To avoid bloating the set of messages the translation team has to cope
with, establish a policy that replication protocol violation error
reports don't need to be translated. Hence, all the new messages here
use errmsg_internal(). A couple of old messages are changed likewise
for consistency.
Along the way, fix some non-idiomatic or outright wrong uses of
hash_search().
Most of these mistakes are new with the "streaming replication"
patch (commit 464824323), but a couple go back a long way.
Back-patch as appropriate.
Discussion: https://postgr.es/m/1719083.1623351052@sss.pgh.pa.us
Commit caba8f0d43 wasn't quite right for msys, as demonstrated by
several buildfarm animals, including jacana and fairywren. We need to
use the msys perl in the archive command, but call it in such a way that
Windows will understand the path. Furthermore, inside the copy script we
need to convert a Windows path to an msys path.
ab55d74 has introduced some tests with rows found as missing in logical
replication subscriptions for partitioned tables, relying on a logic
with a lookup of the logs generated, scanning the whole file. This
commit makes the logic more precise, by scanning the logs only from the
position before the key queries are run to the position where we check
for the logs. This will reduce the risk of issues with log patterns
overlapping with each other if those tests get more complicated in the
future.
Per discussion with Tom Lane.
Discussion: https://postgr.es/m/YMP+Gx2S8meYYHW4@paquier.xyz
Backpatch-through: 13
This variable was present in the list added by 9d660670, but it is not
supported by this branch. Issue noticed while diving into a similar
change for pg_regress.c.
Backpatch-through: 9.6
We were already reporting it, but only after the parallel workers were
finished, which is visibly much later than what happens in a serial
build.
With this change we report it when the leader starts its own sort phase
when participating in the build (the normal case). Now this might
happen a little later than when the workers start their sorting phases,
but a) communicating the actual phase start from workers is likely to be
a hassle, and b) the sort phase start is pretty fuzzy anyway, since
sorting per se is actually initiated by tuplesort.c internally earlier
than tuplesort_performsort() is called.
Backpatch to pg12, where the progress reporting code for CREATE INDEX
went in.
Reported-by: Tomas Vondra <tomas.vondra@enterprisedb.com>
Author: Matthias van de Meent <boekewurm+postgres@gmail.com>
Reviewed-by: Greg Nancarrow <gregn4422@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/1128176d-1eee-55d4-37ca-e63644422adb
apply_handle_tuple_routing(), having detected and reported that
the tuple it needed to update didn't exist, tried to update that
tuple anyway, leading to a null-pointer dereference.
logicalrep_partition_open() failed to ensure that the
LogicalRepPartMapEntry it built for a partition was fully
independent of that for the partition root, leading to
trouble if the root entry was later freed or rebuilt.
Meanwhile, on the publisher's side, pgoutput_change() sometimes
attempted to apply execute_attr_map_tuple() to a NULL tuple.
The first of these was reported by Sergey Bernikov in bug #17055;
I found the other two while developing some test cases for this
sadly under-tested code.
Diagnosis and patch for the first issue by Amit Langote; patches
for the others by me; new test cases by me. Back-patch to v13
where this logic came in.
Discussion: https://postgr.es/m/17055-9ba800ec8522668b@postgresql.org
The code added to mark replication slots invalid in commit c655077639
had the race condition that a slot can be dropped or advanced
concurrently with checkpointer trying to invalidate it. Rewrite the
code to close those races.
The changes to ReplicationSlotAcquire's API added with c655077639 are
not necessary anymore. To avoid an ABI break in released branches, this
commit leaves that unchanged; it'll be changed in a master-only commit
separately.
Backpatch to 13, where this code first appeared.
Reported-by: Andres Freund <andres@anarazel.de>
Author: Andres Freund <andres@anarazel.de>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/20210408001037.wfmk6jud36auhfqm@alap3.anarazel.de
It turns out that worker.c's code path for TRUNCATE was also
careless about establishing a snapshot while executing user-defined
code, allowing the checks added by commit 84f5c2908 to fail when
a trigger is fired in that context.
We could just wrap Push/PopActiveSnapshot around the truncate call,
but it seems better to establish a policy of holding a snapshot
throughout execution of a replication step. To help with that and
possible future requirements, replace the previous ensure_transaction
calls with pairs of begin/end_replication_step calls.
Per report from Mark Dilger. Back-patch to v11, like the previous
changes.
Discussion: https://postgr.es/m/B4A3AF82-79ED-4F4C-A4E5-CD2622098972@enterprisedb.com
This only happens if (1) the new standby has no WAL available locally,
(2) the new standby is starting from the old timeline, (3) the promotion
happened in the WAL segment from which the new standby is starting,
(4) the timeline history file for the new timeline is available from
the archive but the WAL files for are not (i.e. this is a race),
(5) the WAL files for the new timeline are available via streaming,
and (6) recovery_target_timeline='latest'.
Commit ee994272ca introduced this
logic and was an improvement over the previous code, but it mishandled
this case. If recovery_target_timeline='latest' and restore_command is
set, validateRecoveryParameters() can change recoveryTargetTLI to be
different from receiveTLI. If streaming is then tried afterward,
expectedTLEs gets initialized with the history of the wrong timeline.
It's supposed to be a list of entries explaining how to get to the
target timeline, but in this case it ends up with a list of entries
explaining how to get to the new standby's original timeline, which
isn't right.
Dilip Kumar and Robert Haas, reviewed by Kyotaro Horiguchi.
Discussion: http://postgr.es/m/CAFiTN-sE-jr=LB8jQuxeqikd-Ux+jHiXyh4YDiZMPedgQKup0g@mail.gmail.com
The set of subcommands supported by \dAp, \do and \dy was described
incorrectly in psql's --help. The documentation was already consistent
with the code.
Reported-by: inoas, from IRC
Author: Matthijs van der Vleuten
Reviewed-by: Neil Chen
Discussion: https://postgr.es/m/6a984e24-2171-4039-9050-92d55e7b23fe@www.fastmail.com
Backpatch-through: 9.6
Further thought about bug #17050 suggests that it's a good idea
to use CURSOR_OPT_NO_SCROLL for the implicit cursor opened by
a plpgsql FOR-over-query loop. This ensures that, if somebody
commits inside the loop, PersistHoldablePortal won't try to
rewind and re-read the cursor. While we'd have selected NO_SCROLL
anyway if FOR UPDATE/SHARE appears in the query, there are other
hazards with volatile functions; and in any case, it's silly to
expend effort storing rows that we know for certain won't be needed.
(While here, improve the comment in exec_run_select, which was a bit
confused about the rationale for when we can use parallel mode.
Cursor operations aren't a hazard for nameless portals.)
This wasn't an issue until v11, which introduced the possibility
of persisting such cursors. Hence, back-patch to v11.
Per bug #17050 from Алексей Булгаков.
Discussion: https://postgr.es/m/17050-f77aa827dc85247c@postgresql.org
PersistHoldablePortal has long assumed that it should store the
entire output of the query-to-be-persisted, which requires rewinding
and re-reading the output. This is problematic if the query is not
stable: we might get different row contents, or even a different
number of rows, which'd confuse the cursor state mightily.
In the case where the cursor is NO SCROLL, this is very easy to
solve: just store the remaining query output, without any rewinding,
and tweak the portal's cursor state to match. Aside from removing
the semantic problem, this could be significantly more efficient
than storing the whole output.
If the cursor is scrollable, there's not much we can do, but it
was already the case that scrolling a volatile query's result was
pretty unsafe. We can just document more clearly that getting
correct results from that is not guaranteed.
There are already prohibitions in place on using SCROLL with
FOR UPDATE/SHARE, which is one way for a SELECT query to have
non-stable results. We could imagine prohibiting SCROLL when
the query contains volatile functions, but that would be
expensive to enforce. Moreover, it could break applications
that work just fine, if they have functions that are in fact
stable but the user neglected to mark them so. So settle for
documenting the hazard.
While this problem has existed in some guise for a long time,
it got a lot worse in v11, which introduced the possibility
of persisting plpgsql cursors (perhaps implicit ones) even
when they violate the rules for what can be marked WITH HOLD.
Hence, I've chosen to back-patch to v11 but not further.
Per bug #17050 from Алексей Булгаков.
Discussion: https://postgr.es/m/17050-f77aa827dc85247c@postgresql.org
Mis-merge introduced by e2f21ff, where pgwin32_setenv() was listed but
not defined in win32env.c. This had no consequences as this routine
does not exist in this branch.
Only REL_12_STABLE and REL_13_STABLE got that wrong.
Backpatch-through: 12
If autovacuum comes along just after we fill table test_seg with
some data, it will update the stats to the point where we prefer
a plain indexscan over a bitmap scan, breaking the expected
output (as well as the point of the test case). To fix, just
force a bitmap scan to be chosen here.
This has evidently been wrong since commit de1d042f5. It's not
clear why we just recently saw any buildfarm failures due to it;
but prairiedog has failed twice on this test in the past week.
Hence, backpatch to v11 where this test case came in.
An incorrectly-encoded multibyte character near the end of a string
could cause various processing loops to run past the string's
terminating NUL, with results ranging from no detectable issue to
a program crash, depending on what happens to be in the following
memory.
This isn't an issue in the server, because we take care to verify
the encoding of strings before doing any interesting processing
on them. However, that lack of care leaked into client-side code
which shouldn't assume that anyone has validated the encoding of
its input.
Although this is certainly a bug worth fixing, the PG security team
elected not to regard it as a security issue, primarily because
any untrusted text should be sanitized by PQescapeLiteral or
the like before being incorporated into a SQL or psql command.
(If an app fails to do so, the same technique can be used to
cause SQL injection, with probably much more dire consequences
than a mere client-program crash.) Those functions were already
made proof against this class of problem, cf CVE-2006-2313.
To fix, invent PQmblenBounded() which is like PQmblen() except it
won't return more than the number of bytes remaining in the string.
In HEAD we can make this a new libpq function, as PQmblen() is.
It seems imprudent to change libpq's API in stable branches though,
so in the back branches define PQmblenBounded as a macro in the files
that need it. (Note that just changing PQmblen's behavior would not
be a good idea; notably, it would completely break the escaping
functions' defense against this exact problem. So we just want a
version for those callers that don't have any better way of handling
this issue.)
Per private report from houjingyi. Back-patch to all supported branches.
The Msys shell mangles certain patterns in its command line, so avoid
handing arbitrary SQL to psql on the command line and instead use
IPC::Run's redirection facility for stdin. This pattern is already
mostly whats used, but query_poll_until() was not doing the right thing.
Problem discovered on the buildfarm when a new TAP test failed on msys.
The internal SQL queries used by REFRESH MATERIALIZED VIEW CONCURRENTLY
include some aliases for its diff and temporary relations with
rather-generic names: diff, newdata, newdata2 and mv. Depending on the
queries used for the materialized view, using CONCURRENTLY could lead to
some internal failures if the query and those internal aliases conflict.
Those names have been chosen in 841c29c8. This commit switches instead
to a naming pattern which is less likely going to cause conflicts, based
on an idea from Thomas Munro, by appending _$ to those aliases. This is
not perfect as those new names could still conflict, but at least it has
the advantage to keep the code readable and simple while reducing the
likelihood of conflicts to be close to zero.
Reported-by: Mathis Rudolf
Author: Bharath Rupireddy
Reviewed-by: Bernd Helmle, Thomas Munro, Michael Paquier
Discussion: https://postgr.es/m/109c267a-10d2-3c53-b60e-720fcf44d9e8@credativ.de
Backpatch-through: 9.6
Various environment variables were not getting reset in the TAP tests,
which would cause failures depending on the tests or the environment
variables involved. For example, PGSSL{MAX,MIN}PROTOCOLVERSION could
cause failures in the SSL tests. Even worse, a junk value of
PGCLIENTENCODING makes a server startup fail. The list of variables
reset is adjusted in each stable branch depending on what is supported.
While on it, simplify a bit the code per a suggestion from Andrew
Dunstan, using a list of variables instead of doing single deletions.
Reviewed-by: Andrew Dunstan, Daniel Gustafsson
Discussion: https://postgr.es/m/YLbjjRpucIeZ78VQ@paquier.xyz
Backpatch-through: 9.6
Commit 428b260f8 broke planning of cases where row marks are needed
(SELECT FOR UPDATE, etc) and one of the query's tables is a foreign
table that has regular table(s) as inheritance children. We got the
reverse case right, but apparently were thinking that foreign tables
couldn't be inheritance parents. Not so; so we need to be able to
add a CTID junk column while adding a new child, not only a wholerow
junk column.
Back-patch to v12 where the faulty code came in.
Amit Langote
Discussion: https://postgr.es/m/CA+HiwqEmo3FV1LAQ4TVyS2h1WM=kMkZUmbNuZSCnfHvMcUcPeA@mail.gmail.com
This case should be disallowed, just as FOR UPDATE with a plain
GROUP BY is disallowed; FOR UPDATE only makes sense when each row
of the query result can be identified with a single table row.
However, we missed teaching CheckSelectLocking() to check
groupingSets as well as groupClause, so that it would allow
degenerate grouping sets. That resulted in a bad plan and
a null-pointer dereference in the executor.
Looking around for other instances of the same bug, the only one
I found was in examine_simple_variable(). That'd just lead to
silly estimates, but it should be fixed too.
Per private report from Yaoguang Chen.
Back-patch to all supported branches.
Release memory allocated when creating the tuple-conversion map and its
component TupleDescs when its owning sync entry is invalidated.
TupleDescs must also be freed when no map is deemed necessary, to begin
with.
Reported-by: Andres Freund
Author: Amit Langote
Reviewed-by: Takamichi Osumi, Amit Kapila
Backpatch-through: 13, where it was introduced
Discussion: https://postgr.es/m/MEYP282MB166933B1AB02B4FE56E82453B64D9@MEYP282MB1669.AUSP282.PROD.OUTLOOK.COM
This fixes the code compilation on Windows with MSVC and Kerberos, as
a missing implementation of setenv() causes a compilation failure of the
GSSAPI code. This was only reproducible when building the code with
Kerberos, something that buildfarm animal hamerkop has fixed recently.
This issue only happens on 12 and 13, as this code has been introduced
in b0b39f7. HEAD is already able to compile properly thanks to
7ca37fb0, and this commit is a minimal cherry-pick of it.
Thanks to Tom Lane for the discussion.
Discussion: https://postgr.es/m/YLDtm5WGjPxm6ua4@paquier.xyz
Backpatch-through: 12
create_projection_plan contains a hidden assumption (here made
explicit by an Assert) that a projection-capable Path will yield a
projection-capable Plan. Unfortunately, that assumption is violated
only a few lines away, by create_projection_plan itself. This means
that two stacked ProjectionPaths can yield an outcome where we try to
jam the upper path's tlist into a non-projection-capable child node,
resulting in an invalid plan.
There isn't any good reason to have stacked ProjectionPaths; indeed the
whole concept is faulty, since the set of Vars/Aggs/etc needed by the
upper one wouldn't necessarily be available in the output of the lower
one, nor could the lower one create such values if they weren't
available from its input. Hence, we can fix this by adjusting
create_projection_path to strip any top-level ProjectionPath from the
subpath it's given. (This amounts to saying "oh, we changed our
minds about what we need to project here".)
The test case added here only fails in v13 and HEAD; before that, we
don't attempt to shove the Sort into the parallel part of the plan,
for reasons that aren't entirely clear to me. However, all the
directly-related code looks generally the same as far back as v11,
where the hazard was introduced (by d7c19e62a). So I've got no faith
that the same type of bug doesn't exist in v11 and v12, given the
right test case. Hence, back-patch the code changes, but not the
irrelevant test case, into those branches.
Per report from Bas Poot.
Discussion: https://postgr.es/m/534fca83789c4a378c7de379e9067d4f@politie.nl
Parallel query processes that called BlessTupleDesc() for identical
tuple descriptors at the same moment could crash. There was code to
handle that rare case, but it dereferenced a bogus DSA pointer. Repair.
Back-patch to 11, where commit cc5f8136 added support for sharing tuple
descriptors in parallel queries.
Reported-by: Eric Thinnes <e.thinnes@gmx.de>
Discussion: https://postgr.es/m/99aaa2eb-e194-bf07-c29a-1a76b4f2bcf9%40gmx.de
The deliverables of upstream Kerberos on Windows are installed with
paths that do not match our MSVC scripts. First, the include folder was
named "inc/" in our scripts, but the upstream MSIs use "include/".
Second, the build would fail with 64-bit environments as the libraries
are named differently.
This commit adjusts the MSVC scripts to be compatible with the latest
installations of upstream, and I have checked that the compilation was
able to work with the 32-bit and 64-bit installations.
Special thanks to Kondo Yuta for the help in investigating the situation
in hamerkop, which had an incorrect configuration for the GSS
compilation.
Reported-by: Brian Ye
Discussion: https://postgr.es/m/162128202219.27274.12616756784952017465@wrigleys.postgresql.org
Backpatch-through: 9.6
The following parameters have been imprecise, or incorrect, about their
description (PGC_POSTMASTER or PGC_SIGHUP):
- autovacuum_work_mem (docs, as of 9.6~)
- huge_page_size (docs, as of 14~)
- max_logical_replication_workers (docs, as of 10~)
- max_sync_workers_per_subscription (docs, as of 10~)
- min_dynamic_shared_memory (docs, as of 14~)
- recovery_init_sync_method (postgresql.conf.sample, as of 14~)
- remove_temp_files_after_crash (docs, as of 14~)
- restart_after_crash (docs, as of 9.6~)
- ssl_min_protocol_version (docs, as of 12~)
- ssl_max_protocol_version (docs, as of 12~)
This commit adjusts the description of all these parameters to be more
consistent with the practice used for the others.
Revewed-by: Justin Pryzby
Discussion: https://postgr.es/m/YK2ltuLpe+FbRXzA@paquier.xyz
Backpatch-through: 9.6
The error messages, docs, and one of the options were using
'parallel degree' to indicate parallelism used by vacuum command. We
normally use 'parallel workers' at other places so change it for parallel
vacuum accordingly.
Author: Bharath Rupireddy
Reviewed-by: Dilip Kumar, Amit Kapila
Backpatch-through: 13
Discussion: https://postgr.es/m/CALj2ACWz=PYrrFXVsEKb9J1aiX4raA+UBe02hdRp_zqDkrWUiw@mail.gmail.com
SSL renegotiation is already disabled as of 48d23c72, however this does
not prevent the server to comply with a client willing to use
renegotiation. In the last couple of years, renegotiation had its set
of security issues and flaws (like the recent CVE-2021-3449), and it
could be possible to crash the backend with a client attempting
renegotiation.
This commit takes one extra step by disabling renegotiation in the
backend in the same way as SSL compression (f9264d15) or tickets
(97d3a0b0). OpenSSL 1.1.0h has added an option named
SSL_OP_NO_RENEGOTIATION able to achieve that. In older versions
there is an option called SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS that
was undocumented, and could be set within the SSL object created when
the TLS connection opens, but I have decided not to use it, as it feels
trickier to rely on, and it is not official. Note that this option is
not usable in OpenSSL < 1.1.0h as the internal contents of the *SSL
object are hidden to applications.
SSL renegotiation concerns protocols up to TLSv1.2.
Per original report from Robert Haas, with a patch based on a suggestion
by Andres Freund.
Author: Michael Paquier
Reviewed-by: Daniel Gustafsson
Discussion: https://postgr.es/m/YKZBXx7RhU74FlTE@paquier.xyz
Backpatch-through: 9.6
If we redirected a replicated tuple operation into a partition child
table, and then tried to fire AFTER triggers for that event, the
relation cache entry for the child table was already closed. This has
no visible ill effects as long as the entry is still there and still
valid, but an unluckily-timed cache flush could result in a crash or
other misbehavior.
To fix, postpone the ExecCleanupTupleRouting call (which is what
closes the child table) until after we've fired triggers. This
requires a bit of refactoring so that the cleanup function can
have access to the necessary state.
In HEAD, I took the opportunity to simplify some of worker.c's
function APIs based on use of the new ApplyExecutionData struct.
However, it doesn't seem safe/practical to back-patch that aspect,
at least not without a lot of analysis of possible interactions
with a04daa97a.
In passing, add an Assert to afterTriggerInvokeEvents to catch
such cases. This seems worthwhile because we've grown a number
of fairly unstructured ways of calling AfterTriggerEndQuery.
Back-patch to v13, where worker.c grew the ability to deal with
partitioned target tables.
Discussion: https://postgr.es/m/3382681.1621381328@sss.pgh.pa.us
This was previously allowed, but I think that was just an oversight.
It's a clear violation of the rule that a generated column cannot
depend on itself or other generated columns. Moreover, because the
code was relying on the assumption that no such cross-references
exist, it was pretty easy to crash ALTER TABLE and perhaps other
places. Even if you managed not to crash, you got quite unstable,
implementation-dependent results.
Per report from Vitaly Ustinov.
Back-patch to v12 where GENERATED came in.
Discussion: https://postgr.es/m/CAM_DEiWR2DPT6U4xb-Ehigozzd3n3G37ZB1+867zbsEVtYoJww@mail.gmail.com
We consider this supported (though I've got my doubts that it's a
good idea, because tableoid is not immutable). However, several
code paths failed to fill the field in soon enough, causing such
a GENERATED expression to see zero or the wrong value. This
occurred when ALTER TABLE adds a new GENERATED column to a table
with existing rows, and during regular INSERT or UPDATE on a
foreign table with GENERATED columns.
Noted during investigation of a report from Vitaly Ustinov.
Back-patch to v12 where GENERATED came in.
Discussion: https://postgr.es/m/CAM_DEiWR2DPT6U4xb-Ehigozzd3n3G37ZB1+867zbsEVtYoJww@mail.gmail.com
COMMIT/ROLLBACK necessarily destroys all snapshots within the session.
The original implementation of intra-procedure transactions just
cavalierly did that, ignoring the fact that this left us executing in
a rather different environment than normal. In particular, it turns
out that handling of toasted datums depends rather critically on there
being an outer ActiveSnapshot: otherwise, when SPI or the core
executor pop whatever snapshot they used and return, it's unsafe to
dereference any toasted datums that may appear in the query result.
It's possible to demonstrate "no known snapshots" and "missing chunk
number N for toast value" errors as a result of this oversight.
Historically this outer snapshot has been held by the Portal code,
and that seems like a good plan to preserve. So add infrastructure
to pquery.c to allow re-establishing the Portal-owned snapshot if it's
not there anymore, and add enough bookkeeping support that we can tell
whether it is or not.
We can't, however, just re-establish the Portal snapshot as part of
COMMIT/ROLLBACK. As in normal transaction start, acquiring the first
snapshot should wait until after SET and LOCK commands. Hence, teach
spi.c about doing this at the right time. (Note that this patch
doesn't fix the problem for any PLs that try to run intra-procedure
transactions without using SPI to execute SQL commands.)
This makes SPI's no_snapshots parameter rather a misnomer, so in HEAD,
rename that to allow_nonatomic.
replication/logical/worker.c also needs some fixes, because it wasn't
careful to hold a snapshot open around AFTER trigger execution.
That code doesn't use a Portal, which I suspect someday we're gonna
have to fix. But for now, just rearrange the order of operations.
This includes back-patching the recent addition of finish_estate()
to centralize the cleanup logic there.
This also back-patches commit 2ecfeda3e into v13, to improve the
test coverage for worker.c (it was that test that exposed that
worker.c's snapshot management is wrong).
Per bug #15990 from Andreas Wicht. Back-patch to v11 where
intra-procedure COMMIT was added.
Discussion: https://postgr.es/m/15990-eee2ac466b11293d@postgresql.org
Tom Lane
Heikki Linnakangas
Andrew Dunstan
Amit Kapila
Michael Paquier
Alvaro Herrera
Robert Haas
Noah Misch
Thomas Munro