Usually an entry in pg_amop or pg_amproc does not need a dependency on
its amoplefttype/amoprighttype/amproclefttype/amprocrighttype types,
because there is an indirect dependency via the argument types of its
referenced operator or procedure, or via the opclass it belongs to.
However, for some support procedures in some index AMs, the argument
types of the support procedure might not mention the column data type
at all. Also, the amop/amproc entry might be treated as "loose" in
the opfamily, in which case it lacks a dependency on any particular
opclass; or it might be a cross-type entry having a reference to a
datatype that is not its opclass' opcintype.
The upshot of all this is that there are cases where a datatype can
be dropped while leaving behind amop/amproc entries that mention it,
because there is no path in pg_depend showing that those entries
depend on that type. Such entries are harmless in normal activity,
because they won't get used, but they cause problems for maintenance
actions such as dropping the operator family. They also cause pg_dump
to produce bogus output. The previous commit put a band-aid on the
DROP OPERATOR FAMILY failure, but a real fix is needed.
To fix, add pg_depend entries showing that a pg_amop/pg_amproc entry
depends on its lefttype/righttype. To avoid bloating pg_depend too
much, skip this if the referenced operator or function has that type
as an input type. (I did not bother with considering the possible
indirect dependency via the opclass' opcintype; at least in the
reported case, that wouldn't help anyway.)
Probably, the reason this has escaped notice for so long is that
add-on datatypes and relevant opclasses/opfamilies are usually
packaged as extensions nowadays, so that there's no way to drop
a type without dropping the referencing opclasses/opfamilies too.
Still, in the absence of pg_depend entries there's nothing that
constrains DROP EXTENSION to drop the opfamily entries before the
datatype, so it seems possible for a DROP failure to occur anyway.
The specific case that was reported doesn't fail in v13, because
v13 prefers to attach the support procedure to the opclass not the
opfamily. But it's surely possible to construct other edge cases
that do fail in v13, so patch that too.
Per report from Yoran Heling. Back-patch to all supported branches.
Discussion: https://postgr.es/m/Z1MVCOh1hprjK5Sf@gmai021
The current code calls array_eq() and does not provide FmgrInfo. This commit
provides initialization of FmgrInfo and uses C collation as the safe option
for text comparison because we don't know anything about the semantics of
opclass options.
Backpatch to 13, where opclass options were introduced.
Reported-by: Nicolas Maus
Discussion: https://postgr.es/m/18692-72ea398df3ec6712%40postgresql.org
Backpatch-through: 13
The SQL spec mandates that SET SESSION AUTHORIZATION implies
SET ROLE NONE. We tried to implement that within the lowest-level
functions that manipulate these settings, but that was a bad idea.
In particular, guc.c assumes that it doesn't matter in what order
it applies GUC variable updates, but that was not the case for these
two variables. This problem, compounded by some hackish attempts to
work around it, led to some security-grade issues:
* Rolling back a transaction that had done SET SESSION AUTHORIZATION
would revert to SET ROLE NONE, even if that had not been the previous
state, so that the effective user ID might now be different from what
it had been.
* The same for SET SESSION AUTHORIZATION in a function SET clause.
* If a parallel worker inspected current_setting('role'), it saw
"none" even when it should see something else.
Also, although the parallel worker startup code intended to cope
with the current role's pg_authid row having disappeared, its
implementation of that was incomplete so it would still fail.
Fix by fully separating the miscinit.c functions that assign
session_authorization from those that assign role. To implement the
spec's requirement, teach set_config_option itself to perform "SET
ROLE NONE" when it sets session_authorization. (This is undoubtedly
ugly, but the alternatives seem worse. In particular, there's no way
to do it within assign_session_authorization without incompatible
changes in the API for GUC assign hooks.) Also, improve
ParallelWorkerMain to directly set all the relevant user-ID variables
instead of relying on some of them to get set indirectly. That
allows us to survive not finding the pg_authid row during worker
startup.
In v16 and earlier, this includes back-patching 9987a7bf3 which
fixed a violation of GUC coding rules: SetSessionAuthorization
is not an appropriate place to be throwing errors from.
Security: CVE-2024-10978
Now that lstat() reports junction points with S_IFLNK/S_ISLINK(), and
unlink() can unlink them, there is no need for conditional code for
Windows in a few places. That was expressed by testing for WIN32 or
S_ISLNK, which we can now constant-fold.
The coding around pgwin32_is_junction() was a bit suspect anyway, as we
never checked for errors, and we also know that errors can be spuriously
reported because of transient sharing violations on this OS. The
lstat()-based code has handling for that.
This also reverts 4fc6b6ee on master only. That was done because
lstat() didn't previously work for symlinks (junction points), but now
it does.
Tested-by: Andrew Dunstan <andrew@dunslane.net>
Discussion: https://postgr.es/m/CA%2BhUKGLfOOeyZpm5ByVcAt7x5Pn-%3DxGRNCvgiUPVVzjFLtnY0w%40mail.gmail.com
(cherry picked from commit 5fc88c5d53)
Author: Thomas Munro <tmunro@postgresql.org>
Author: Alexandra Wang <alexandra.wang.oss@gmail.com>
* In DetachPartitionFinalize() we were applying a tuple conversion map
to tuples that didn't need one, which can lead to erratic behavior if
a partitioned table has a partition with a different column order, as
reported by Alexander Lakhin. This was introduced by 53af9491a0.
Don't do that. Also, modify a recently added test case to exercise
this.
* The same function as well as CloneFkReferenced() were acquiring
AccessShareLock on a partition, only to have CreateTrigger() later
acquire ShareRowExclusiveLock on it. This can lead to deadlock by
lock escalation, unnecessarily. Avoid that by acquiring the stronger
lock to begin with. This probably dates back to branch 12, but I have
never seen a report of this being a problem in the field.
* Innocuous but wasteful: also introduced by 53af9491a0, we were
reading a pg_constraint tuple from syscache that we don't need, as
reported by Tender Wang. Don't.
Backpatch to 15.
Discussion: https://postgr.es/m/461e9c26-2076-8224-e119-84998b6a784e@gmail.com
... to fix bugs when the referenced table is partitioned.
The catalog representation we chose for foreign keys connecting
partitioned tables (in commit f56f8f8da6) is inconvenient, in the
sense that a standalone table has a different way to represent the
constraint when referencing a partitioned table, than when the same
table becomes a partition (and vice versa). Because of this, we need to
create additional catalog rows on detach (pg_constraint and pg_trigger),
and remove them on attach. We were doing some of those things, but not
all of them, leading to missing catalog rows in certain cases.
The worst problem seems to be that we are missing action triggers after
detaching a partition, which means that you could update/delete rows
from the referenced partitioned table that still had referencing rows on
that table, the server failing to throw the required errors.
!!!
Note that this means existing databases with FKs that reference
partitioned tables might have rows that break relational integrity, on
tables that were once partitions on the referencing side of the FK.
Another possible problem is that trying to reattach a table
that had been detached would fail indicating that internal triggers
cannot be found, which from the user's point of view is nonsensical.
In branches 15 and above, we fix this by creating a new helper function
addFkConstraint() which is in charge of creating a standalone
pg_constraint row, and repurposing addFkRecurseReferencing() and
addFkRecurseReferenced() so that they're only the recursive routine for
each side of the FK, and they call addFkConstraint() to create
pg_constraint at each partitioning level and add the necessary triggers.
These new routines can be used during partition creation, partition
attach and detach, and foreign key creation. This reduces redundant
code and simplifies the flow.
In branches 14 and 13, we have a much simpler fix that consists on
simply removing the constraint on detach. The reason is that those
branches are missing commit f4566345cf, which reworked the way this
works in a way that we didn't consider back-patchable at the time.
We opted to leave branch 12 alone, because it's different from branch 13
enough that the fix doesn't apply; and because it is going in EOL mode
very soon, patching it now might be worse since there's no way to undo
the damage if it goes wrong.
Existing databases might need to be repaired.
In the future we might want to rethink the catalog representation to
avoid this problem, but for now the code seems to do what's required to
make the constraints operate correctly.
Co-authored-by: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
Co-authored-by: Tender Wang <tndrwang@gmail.com>
Co-authored-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reported-by: Guillaume Lelarge <guillaume@lelarge.info>
Reported-by: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
Reported-by: Thomas Baehler (SBB CFF FFS) <thomas.baehler2@sbb.ch>
Discussion: https://postgr.es/m/20230420144344.40744130@karst
Discussion: https://postgr.es/m/20230705233028.2f554f73@karst
Discussion: https://postgr.es/m/GVAP278MB02787E7134FD691861635A8BC9032@GVAP278MB0278.CHEP278.PROD.OUTLOOK.COM
Discussion: https://postgr.es/m/18541-628a61bc267cd2d3@postgresql.org
If the query is rewritten into a NOTIFY command by a DO INSTEAD
rule, we'd get an assertion failure, or in non-assert builds
issue a rather confusing error message. Improve that.
Also fix a longstanding grammar mistake in a nearby error message.
Per bug #18664 from Alexander Lakhin. Back-patch to all supported
branches.
Tender Wang and Tom Lane
Discussion: https://postgr.es/m/18664-ffd0ebc2386598df@postgresql.org
The previous commit fixed some ways of losing an inplace update. It
remained possible to lose one when a backend working toward a
heap_update() copied a tuple into memory just before inplace update of
that tuple. In catalogs eligible for inplace update, use LOCKTAG_TUPLE
to govern admission to the steps of copying an old tuple, modifying it,
and issuing heap_update(). This includes MERGE commands. To avoid
changing most of the pg_class DDL, don't require LOCKTAG_TUPLE when
holding a relation lock sufficient to exclude inplace updaters.
Back-patch to v12 (all supported versions). In v13 and v12, "UPDATE
pg_class" or "UPDATE pg_database" can still lose an inplace update. The
v14+ UPDATE fix needs commit 86dc90056d,
and it wasn't worth reimplementing that fix without such infrastructure.
Reviewed by Nitin Motiani and (in earlier versions) Heikki Linnakangas.
Discussion: https://postgr.es/m/20231027214946.79.nmisch@google.com
As previously-added tests demonstrated, heap_inplace_update() could
instead update an unrelated tuple of the same catalog. It could lose
the update. Losing relhasindex=t was a source of index corruption.
Inplace-updating commands like VACUUM will now wait for heap_update()
commands like GRANT TABLE and GRANT DATABASE. That isn't ideal, but a
long-running GRANT already hurts VACUUM progress more just by keeping an
XID running. The VACUUM will behave like a DELETE or UPDATE waiting for
the uncommitted change.
For implementation details, start at the systable_inplace_update_begin()
header comment and README.tuplock. Back-patch to v12 (all supported
versions). In back branches, retain a deprecated heap_inplace_update(),
for extensions.
Reported by Smolkin Grigory. Reviewed by Nitin Motiani, (in earlier
versions) Heikki Linnakangas, and (in earlier versions) Alexander
Lakhin.
Discussion: https://postgr.es/m/CAMp+ueZQz3yDk7qg42hk6-9gxniYbp-=bG2mgqecErqR5gGGOA@mail.gmail.com
Since we introduced unlogged sequences in v15, identity sequences
have defaulted to having the same persistence as their owning table.
However, it is possible to change that with ALTER SEQUENCE, and
pg_dump tries to preserve the logged-ness of sequences when it doesn't
match (as indeed it wouldn't for an unlogged table from before v15).
The fly in the ointment is that ALTER SEQUENCE SET [UN]LOGGED fails
in binary-upgrade mode, because it needs to assign a new relfilenode
which we cannot permit in that mode. Thus, trying to pg_upgrade a
database containing a mismatching identity sequence failed.
To fix, add syntax to ADD/ALTER COLUMN GENERATED AS IDENTITY to allow
the sequence's persistence to be set correctly at creation, and use
that instead of ALTER SEQUENCE SET [UN]LOGGED in pg_dump. (I tried to
make SET [UN]LOGGED work without any pg_dump modifications, but that
seems too fragile to be a desirable answer. This way should be
markedly faster anyhow.)
In passing, document the previously-undocumented SEQUENCE NAME option
that pg_dump also relies on for identity sequences; I see no value
in trying to pretend it doesn't exist.
Per bug #18618 from Anthony Hsu.
Back-patch to v15 where we invented this stuff.
Discussion: https://postgr.es/m/18618-d4eb26d669ed110a@postgresql.org
As introduced by f9900df5f9, a REINDEX CONCURRENTLY job done for an
index with predicates or expressions would set PROC_IN_SAFE_IC in its
MyProc->statusFlags, causing it to be ignored by other concurrent
operations.
Such concurrent index rebuilds should never be ignored, as a predicate
or an expression could call a user-defined function that accesses a
different table than the table where the index is rebuilt.
A test that uses injection points is added, backpatched down to 17.
Michail has proposed a different test, but I have added something
simpler with more coverage.
Oversight in f9900df5f9.
Author: Michail Nikolaev
Discussion: https://postgr.es/m/CANtu0oj9A3kZVduFTG0vrmGnKB+DCHgEpzOp0qAyOgmks84j0w@mail.gmail.com
Backpatch-through: 14
Add a comment explaining dropdb() can't rely on syscache. The issue with
flattened rows was fixed by commit 0f92b230f8, but better to have
a clear explanation why the systable scan is necessary. The other places
doing in-place updates on pg_database have the same comment.
Suggestion and patch by Yugo Nagata. Backpatch to 12, same as the fix.
Author: Yugo Nagata
Backpatch-through: 12
Discussion: https://postgr.es/m/CAJTYsWWNkCt+-UnMhg=BiCD3Mh8c2JdHLofPxsW3m2dkDFw8RA@mail.gmail.com
Commit c66a7d75e6 modified DROP DATABASE so that if interrupted, the
database is known to be in an invalid state and can only be dropped.
This is done by setting a flag using an in-place update, so that it's
not lost in case of rollback.
For databases with many ACLs, this may however fail like this:
ERROR: wrong tuple length
This happens because with many ACLs, the pg_database.datacl attribute
gets TOASTed. The dropdb() code reads the tuple from the syscache, which
means it's detoasted. But the in-place update expects the tuple length
to match the on-disk tuple.
Fixed by reading the tuple from the catalog directly, not from syscache.
Report and fix by Ayush Tiwari. Backpatch to 12. The DROP DATABASE fix
was backpatched to 11, but 11 is EOL at this point.
Reported-by: Ayush Tiwari
Author: Ayush Tiwari
Reviewed-by: Tomas Vondra
Backpatch-through: 12
Discussion: https://postgr.es/m/CAJTYsWWNkCt+-UnMhg=BiCD3Mh8c2JdHLofPxsW3m2dkDFw8RA@mail.gmail.com
Trying to attach a table as a partition which is already on the
referenced side of a foreign key on the partitioned table that it is
being attached to, leads to strange behavior: we try to clone the
foreign key from the parent to the partition, but this new FK points to
the partition itself, and the mix of pg_constraint rows and triggers
doesn't behave well.
Rather than trying to untangle the mess (which might be possible given
sufficient time), I opted to forbid the ATTACH. This doesn't seem a
problematic restriction, given that we already fail to create the
foreign key if you do it the other way around, that is, having the
partition first and the FK second.
Backpatch to all supported branches.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Discussion: https://postgr.es/m/18541-628a61bc267cd2d3@postgresql.org
This reverts commit 4853630537.
Some buildfarm animals are failing with "cannot change
"client_encoding" during a parallel operation". It looks like
assign_client_encoding is unhappy at being asked to roll back a
client_encoding setting after a parallel worker encounters a
failure. There must be more to it though: why didn't I see this
during local testing? In any case, it's clear that moving the
RestoreGUCState() call is not as side-effect-free as I thought.
Given that the bug f5f30c22e intended to fix has gone unreported
for years, it's not something that's urgent to fix; I'm not
willing to risk messing with it further with only days to our
next release wrap.
Parallel workers failed after a sequence like
BEGIN;
CREATE USER foo;
SET SESSION AUTHORIZATION foo;
because check_session_authorization could not see the uncommitted
pg_authid row for "foo". This is because we ran RestoreGUCState()
in a separate transaction using an ordinary just-created snapshot.
The same disease afflicts any other GUC that requires catalog lookups
and isn't forgiving about the lookups failing.
To fix, postpone RestoreGUCState() into the worker's main transaction
after we've set up a snapshot duplicating the leader's. This affects
check_transaction_isolation and check_transaction_deferrable, which
think they should only run during transaction start. Make them
act like check_transaction_read_only, which already knows it should
silently accept the value when InitializingParallelWorker.
Per bug #18545 from Andrey Rachitskiy. Back-patch to all
supported branches, because this has been wrong for awhile.
Discussion: https://postgr.es/m/18545-feba138862f19aaa@postgresql.org
ANALYZE sets relhassubclass=f when a partitioned table no longer has
partitions. An ANALYZE doing that proceeded to apply the inplace update
of pg_class.reltuples to the old pg_class tuple instead of the new
tuple, losing that reltuples=0 change if the ANALYZE committed.
Non-partitioning inheritance trees were unaffected. Back-patch to v14,
where commit 375aed36ad introduced
maintenance of partitioned table pg_class.reltuples.
Reported by Alexander Lakhin.
Discussion: https://postgr.es/m/a295b499-dcab-6a99-c06e-01cf60593344@gmail.com
When a partitioned table has an index that doesn't support a constraint,
but a partition has an equivalent index that does, then a DETACH
operation would misbehave: a crash in assertion-enabled systems (because
we fail to find the constraint in the parent that we expect to), or a
broken coninhcount value (-1) in production systems (because we blindly
believe that we've successfully detached the parent).
While we should reject an ATTACH of a partition with such an index, we
have failed to do so in existing releases, so adding an error in stable
releases might break the (unlikely) existing applications that rely on
this behavior. At this point I don't even want to reject them in
master, because it'd break pg_upgrade if such databases exist, and there
would be no easy way to fix existing databases without expensive index
rebuilds.
(Later on we could add ALTER TABLE ... ADD CONSTRAINT USING INDEX to
partitioned tables, which would allow the user to fix such patterns. At
that point we could add more restrictions to prevent the problem from
its root.)
Also, add a test case that leaves one table in this condition, so that
we can verify that pg_upgrade continues to work if we later decide to
change the policy on the master branch.
Backpatch to all supported branches.
Co-authored-by: Tender Wang <tndrwang@gmail.com>
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/18500-62948b6fe5522f56@postgresql.org
ProcessIncomingNotify is called from the main processing loop that
normally runs in MessageContext. That outer-loop code assumes that
whatever it allocates will be cleaned up when we're done processing
the current client message --- but if we service a notify interrupt,
then whatever gets allocated before the next switch into
MessageContext will be permanently leaked in TopMemoryContext,
because CommitTransactionCommand sets CurrentMemoryContext to
TopMemoryContext. There are observable leaks associated with
(at least) encoding conversion of incoming queries and parameters
attached to Bind messages.
sinval catchup interrupts have a similar problem. There might be
others, but I've not identified any other clear cases.
To fix, take care to save and restore CurrentMemoryContext across
the Start/CommitTransactionCommand calls in these functions.
Per bug #18512 from wizardbrony. Commit to back branches only;
in HEAD, this was dealt with by the riskier but more thoroughgoing
approach in commit 1afe31f03.
Discussion: https://postgr.es/m/3478884.1718656625@sss.pgh.pa.us
Commit 5b562644fe added a comment that
SetRelationHasSubclass() callers must hold this lock. When commit
17f206fbc8 extended use of this column to
partitioned indexes, it didn't take the lock. As the latter commit
message mentioned, we currently never reset a partitioned index to
relhassubclass=f. That largely avoids harm from the lock omission. The
cause for fixing this now is to unblock introducing a rule about locks
required to heap_update() a pg_class row. This might cause more
deadlocks. It gives minor user-visible benefits:
- If an ALTER INDEX SET TABLESPACE runs concurrently with ALTER TABLE
ATTACH PARTITION or CREATE PARTITION OF, one transaction blocks
instead of failing with "tuple concurrently updated". (Many cases of
DDL concurrency still fail that way.)
- Match ALTER INDEX ATTACH PARTITION in choosing to lock the index.
While not user-visible today, we'll need this if we ever make something
set the flag to false for a partitioned index, like ANALYZE does today
for tables. Back-patch to v12 (all supported versions), the plan for
the commit relying on the new rule. In back branches, add
LockOrStrongerHeldByMe() instead of adding a LockHeldByMe() parameter.
Reviewed (in an earlier version) by Robert Haas.
Discussion: https://postgr.es/m/20240611024525.9f.nmisch@google.com
These commands already make the persistence of owned sequences follow
owned table persistence changes. They didn't lock those sequences.
They lost the effect of nextval() calls that other sessions make after
the ALTER TABLE command, before the ALTER TABLE transaction commits.
Fix by acquiring the same lock that ALTER SEQUENCE SET { LOGGED |
UNLOGGED } acquires. This might cause more deadlocks. Back-patch to
v15, where commit 344d62fb9a introduced
unlogged sequences.
Reviewed (in an earlier version) by Robert Haas.
Discussion: https://postgr.es/m/20240611024525.9f.nmisch@google.com
afterTriggerInvokeEvents and AfterTriggerExecute have always
treated it as an error if the trigger OID mentioned in a queued
after-trigger event can't be found. However, that fails to
account for the edge case where the trigger's been dropped in
the current transaction since queueing the event. There seems
no very good reason to disallow that case, so instead silently
do nothing if the trigger OID can't be found.
This does give up a little bit of bug-detection ability, but I don't
recall that these error messages have ever actually revealed a bug,
so it seems mostly theoretical. Alternatives such as marking
pending events DONE at the time of dropping a trigger would be
complicated and perhaps introduce bugs of their own.
Per bug #18517 from Alexander Lakhin. Back-patch to all
supported branches.
Discussion: https://postgr.es/m/18517-af2d19882240902c@postgresql.org
Normally this case isn't even reachable by non-superusers, since
permissions checks prevent naming such a table. However, it is
possible to make it happen by altering a parent table whose child
is another session's temp table.
We definitely can't support any such ALTER that requires modifying
the contents of such a table, since we lack access to the other
session's temporary-buffer pool. But there seems no good reason
to allow it even if it'd only require changing catalog contents.
One reason not to allow it is that we'd rather not expose the
implementation-dependent behavior of whether a specific ALTER
requires touching the table contents. Another is that there may
be (in future, even if not today) optimizations that assume that
a session's own temp tables won't be modified by other sessions.
Hence, add a RELATION_IS_OTHER_TEMP() check to all the places
where ALTER TABLE currently does CheckTableNotInUse(). (I looked
through all other callers of CheckTableNotInUse(), and they seem
OK already.)
Per bug #18492 from Alexander Lakhin. Back-patch to all supported
branches.
Discussion: https://postgr.es/m/18492-c7a2634bf4968763@postgresql.org
Most of the infrastructure for procedure arguments was already
okay with polymorphic output arguments, but it turns out that
CallStmtResultDesc() was a few bricks shy of a load here. It thought
all it needed to do was call build_function_result_tupdesc_t, but
that function specifically disclaims responsibility for resolving
polymorphic arguments. Failing to handle that doesn't seem to be
a problem for CALL in plpgsql, but CALL from plain SQL would get
errors like "cannot display a value of type anyelement", or even
crash outright.
In v14 and later we can simply examine the exposed types of the
CallStmt.outargs nodes to get the right type OIDs. But it's a lot
more complicated to fix in v12/v13, because those versions don't
have CallStmt.outargs, nor do they do expand_function_arguments
until ExecuteCallStmt runs. We have to duplicatively run
expand_function_arguments, and then re-determine which elements
of the args list are output arguments.
Per bug #18463 from Drew Kimball. Back-patch to all supported
versions, since it's busted in all of them.
Discussion: https://postgr.es/m/18463-f8cd77e12564d8a2@postgresql.org
Presently, when this function is called for an unlogged sequence on
a standby server, it will error out with a message like
ERROR: could not open file "base/5/16388": No such file or directory
Since the pg_sequences system view uses pg_sequence_last_value(),
it can error similarly. To fix, modify the function to return NULL
for unlogged sequences on standby servers. Since this bug is
present on all versions since v15, this approach is preferable to
making the ERROR nicer because we need to repair the pg_sequences
view without modifying its definition on released versions. For
consistency, this commit also modifies the function to return NULL
for other sessions' temporary sequences. The pg_sequences view
already appropriately filters out such sequences, so there's no bug
there, but we might as well offer some defense in case someone
invokes this function directly.
Unlogged sequences were first introduced in v15, but temporary
sequences are much older, so while the fix for unlogged sequences
is only back-patched to v15, the temporary sequence portion is
back-patched to all supported versions.
We could also remove the privilege check in the pg_sequences view
definition in v18 if we modify this function to return NULL for
sequences for which the current user lacks privileges, but that is
left as a future exercise for when v18 development begins.
Reviewed-by: Tom Lane, Michael Paquier
Discussion: https://postgr.es/m/20240501005730.GA594666%40nathanxps13
Backpatch-through: 12
vac_update_datfrozenxid() did multiple loads of relfrozenxid and
relminmxid from buffer memory, and it assumed each would get the same
value. Not so if a concurrent vac_update_relstats() did an inplace
update. Commit 2d2e40e3be fixed the same
kind of bug in vac_truncate_clog(). Today's bug could cause the
rel-level field and XIDs in the rel's rows to precede the db-level
field. A cluster having such values should VACUUM affected tables.
Back-patch to v12 (all supported versions).
Discussion: https://postgr.es/m/20240423003956.e7.nmisch@google.com
ALTER COLUMN TYPE wasn't expecting to find any pg_proc objects
depending on the column whose type is to be altered. That indeed
wasn't possible when this code was written, but it is possible
since we introduced new-style SQL function bodies.
It's about as difficult to fix this case as it is to fix dependent
views, and we've been punting on those for years, so I don't feel
too awful about punting for functions too. (I sure wouldn't risk
back-patching such code.) So just throw a more user-facing error.
Also, adjust some of the existing comments to reflect that these
are all pretty much the same issue.
(This patch also fixes it so we will tolerate finding such a
dependency during ALTER COLUMN SET EXPRESSION; in that, we need
not do anything to the function, so no error is wanted. That
problem is new in HEAD.)
Per bug #18449 from Alexander Lakhin. Back-patch to v14 where
we added new-style SQL functions.
Discussion: https://postgr.es/m/18449-f8248467aaa294d5@postgresql.org
When specifying the createdb strategy, the documentation suggests valid
options are FILE_COPY and WAL_LOG, but the code does case-sensitive
comparison and accepts only "file_copy" and "wal_log" as valid.
Fixed by doing a case-insensitive comparison using pg_strcasecmp(), same
as for other string parameters nearby.
While at it, apply fmtId() to a nearby "locale_provider". This already
did the comparison in case-insensitive way, but the value would not be
double-quoted, confusing the parser and the error message.
Backpatch to 15, where the strategy was introduced.
Backpatch-through: 15
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/90c6913a-1dd2-42b4-8365-ce3b09c39b17@enterprisedb.com
Ordinary ALTER TABLE SET SCHEMA will also move any owned sequences
into the new schema. We failed to do likewise for foreign tables,
because AlterTableNamespaceInternal believed that only certain
relkinds could have indexes, owned sequences, or constraints.
We could simply add foreign tables to that relkind list, but it
seems likely that the same oversight could be made again in
future. Instead let's remove the relkind filter altogether.
These functions shouldn't cost much when there are no objects
that they need to process, and surely this isn't an especially
performance-critical case anyway.
Per bug #18407 from Vidushi Gupta. Back-patch to all supported
branches.
Discussion: https://postgr.es/m/18407-4fd07373d252c6a0@postgresql.org
When assertions are disabled, the built SQL statement is invalid and
you get a "syntax error". So this isn't a serious problem, but let's
avoid the assertion failure.
Backpatch to all supported versions.
Reviewed-by: Noah Misch
The internal commands in REFRESH MATERIALIZED VIEW CONCURRENTLY are
correctly executed in SECURITY_RESTRICTED_OPERATION mode, except for
creating the temporary "diff" table, because you cannot create
temporary tables in SRO mode. But creating the temporary "diff" table
is a pretty complex CTAS command that selects from another temporary
table created earlier in the command. If you can cajole that CTAS
command to execute code defined by the table owner, the table owner
can run code with the privileges of the user running the REFRESH
command.
The proof-of-concept reported to the security team relied on CREATE
RULE to convert the internally-built temp table to a view. That's not
possible since commit b23cd185fd, and I was not able to find a
different way to turn the SELECT on the temp table into code
execution, so as far as I know this is only exploitable in v15 and
below. That's a fiddly assumption though, so apply this patch to
master and all stable versions.
Thanks to Pedro Gallegos for the report.
Security: CVE-2023-5869
Reviewed-by: Noah Misch
An OS crash could leave PG_VERSION empty or missing. The same symptom
appeared in a backup by block device snapshot, taken after the next
checkpoint and before the OS flushes the PG_VERSION blocks. Device
snapshots are not a documented backup method, however. Back-patch to
v15, where commit 9c08aea6a3 introduced
STRATEGY=WAL_LOG and made it the default.
Discussion: https://postgr.es/m/20240130195003.0a.nmisch@google.com
Restoring a base backup taken in the middle of CreateDirAndVersionFile()
or write_relmap_file() would lose the function's effects. The symptom
was absence of the database directory, PG_VERSION file, or
pg_filenode.map. If missing the directory, recovery would fail. Either
missing file would not fail recovery but would render the new database
unusable. Fix CreateDirAndVersionFile() with the transam/README "action
first and then write a WAL entry" strategy. That has a side benefit of
moving filesystem mutations out of a critical section, reducing the ways
to PANIC. Fix the write_relmap_file() call with a lock acquisition, so
it interacts with checkpoints like non-CREATE DATABASE calls do.
Back-patch to v15, where commit 9c08aea6a3
introduced STRATEGY=WAL_LOG and made it the default.
Discussion: https://postgr.es/m/20240130195003.0a.nmisch@google.com
This commit addresses a set of issues when changing token type mappings
in a text search configuration when using duplicated token names:
- ADD MAPPING would fail on insertion because of a constraint failure
after inserting the same mapping.
- ALTER MAPPING with an "overridden" configuration failed with "tuple
already updated by self" when the token mappings are removed.
- DROP MAPPING failed with "tuple already updated by self", like
previously, but in a different code path.
The code is refactored so the token names (with their numbers) are
handled as a List with unique members rather than an array with numbers,
ensuring that no duplicates mess up with the catalog inserts, updates
and deletes. The list is generated by getTokenTypes(), with the same
error handling as previously while duplicated tokens are discarded from
the list used to work on the catalogs.
Regression tests are expanded to cover much more ground for the cases
fixed by this commit, as there was no coverage for the code touched in
this commit. A bit more is done regarding the fact that a token name
not supported by a configuration's parser should result in an error even
if IF EXISTS is used in a DROP MAPPING clause. This is implied in the
code but there was no coverage for that, and it was very easy to miss.
These issues exist since at least their introduction in core with
140d4ebcb4, so backpatch all the way down.
Reported-by: Alexander Lakhin
Author: Tender Wang, Michael Paquier
Discussion: https://postgr.es/m/18310-1eb233c5908189c8@postgresql.org
Backpatch-through: 12
We seem to have only documented a foreign key can reference the columns of
a primary key or unique constraint. Here we adjust the documentation
to mention columns in a non-partial unique index can be mentioned too.
The header comment for transformFkeyCheckAttrs() also didn't mention
unique indexes, so fix that too. In passing make that header comment
reflect reality in the various other aspects where it deviated from it.
Bug: 18295
Reported-by: Gilles PARC
Author: Laurenz Albe, David Rowley
Discussion: https://www.postgresql.org/message-id/18295-0ed0fac5c9f7b17b%40postgresql.org
Backpatch-through: 12
This command, when used to add a column on a parent table with a complex
inheritance tree, tried to update multiple times the same tuple in
pg_attribute for a child table when incrementing attinhcount, causing
failures with "tuple already updated by self" because of a missing
CommandCounterIncrement() between two updates.
This exists for a rather long time, so backpatch all the way down.
Reported-by: Alexander Lakhin
Author: Tender Wang
Reviewed-by: Richard Guo
Discussion: https://postgr.es/m/18297-b04cd83a55b51e35@postgresql.org
Backpatch-through: 12
When ExecBRUpdateTriggers switches to a new target tuple as a result
of the EvalPlanQual logic, it must form a new proposed update tuple.
Since commit 86dc90056, that tuple (the result of
ExecGetUpdateNewTuple) has been a virtual tuple that might contain
pointers to by-ref fields of the new target tuple (in "oldslot").
However, immediately after that we materialize oldslot, causing it to
drop its buffer pin, whereupon the by-ref pointers are unsafe to use.
This is a live bug only when the new target tuple is in a different
page than the original target tuple, since we do still hold a pin on
the original one. (Before 86dc90056, there was no bug because the
EPQ plantree would hold a pin on the new target tuple; but now that's
not assured.) To fix, forcibly materialize the new tuple before we
materialize oldslot. This costs nothing since we would have done that
shortly anyway.
The real-world impact of this is probably minimal. A visible failure
could occur if the new target tuple's buffer were recycled for some
other page in the short interval before we materialize newslot within
the trigger-calling loop; but that's quite unlikely given that we'd
just touched that page. There's a larger hazard that some other
process could prune and repack that page within the window. We have
lock on the new target tuple, but that wouldn't prevent it being moved
on the page.
Alexander Lakhin and Tom Lane, per bug #17798 from Alexander Lakhin.
Back-patch to v14 where 86dc90056 came in.
Discussion: https://postgr.es/m/17798-0907404928dcf0dd@postgresql.org
In v16 and up (since commit afbfc0298), large object ownership
checking has been broken because object_ownercheck() didn't take care
of the discrepancy between our object-address representation of large
objects (classId == LargeObjectRelationId) and the catalog where their
ownership info is actually stored (LargeObjectMetadataRelationId).
This resulted in failures such as "unrecognized class ID: 2613"
when trying to update blob properties as a non-superuser.
Poking around for related bugs, I found that AlterObjectOwner_internal
would pass the wrong classId to the PostAlterHook in the no-op code
path where the large object already has the desired owner. Also,
recordExtObjInitPriv checked for the wrong classId; that bug is only
latent because the stanza is dead code anyway, but as long as we're
carrying it around it should be less wrong. These bugs are quite old.
In HEAD, we can reduce the scope for future bugs of this ilk by
changing AlterObjectOwner_internal's API to let the translation happen
inside that function, rather than requiring callers to know about it.
A more bulletproof fix, perhaps, would be to start using
LargeObjectMetadataRelationId as the dependency and object-address
classId for blobs. However that has substantial risk of breaking
third-party code; even within our own code, it'd create hassles
for pg_dump which would have to cope with a version-dependent
representation. For now, keep the status quo.
Discussion: https://postgr.es/m/2650449.1702497209@sss.pgh.pa.us
This fixes an error introduced by efb0ef909f, that changed the
description of this field to "shared/local" while these I/O timings
relate to shared buffers. This information is available when
track_io_timing is enabled. Note that HEAD has added new counters for
local buffers in 295c36c0c1, so there is no need to touch it. The
description is updated to "shared" to be compatible with HEAD.
Per discussion with Nazir Bilal Yavuz and Hubert Depesz Lubaczewski,
whose EXPLAIN analyzer tool was not actually able to parse the previous
term because of the slash character.
Discussion: https://postgr.es/m/ZTCTiUqm_H3iBihl@paquier.xyz
Backpatch-through: 15
When creating a partitioned index, the partition key must be a subset
of the index's columns. But this currently doesn't check that the
collations between the partition key and the index definition match.
So you can construct a unique index that fails to enforce uniqueness.
(This would most likely involve a nondeterministic collation, so it
would have to be crafted explicitly and is not something that would
just happen by accident.)
This patch adds the required collation check. As a result, any
previously allowed unique index that has a collation mismatch would no
longer be allowed to be created.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/3327cb54-f7f1-413b-8fdb-7a9dceebb938%40eisentraut.org
The DROP STATISTICS code failed to properly lock the table, leading to
ERROR: tuple concurrently deleted
when executed concurrently with ANALYZE.
Fixed by modifying RemoveStatisticsById() to acquire the same lock as
ANALYZE. This function is called only by DROP STATISTICS, as ANALYZE
calls RemoveStatisticsDataById() directly.
Reported by Justin Pryzby, fix by me. Backpatch through 12. The code was
like this since it was introduced in 10, but older releases are EOL.
Reported-by: Justin Pryzby
Reviewed-by: Tom Lane
Backpatch-through: 12
Discussion: https://postgr.es/m/ZUuk-8CfbYeq6g_u@pryzbyj2023
contain_mutable_functions and contain_volatile_functions give
reliable answers only after expression preprocessing (specifically
eval_const_expressions). Some places understand this, but some did
not get the memo --- which is not entirely their fault, because the
problem is documented only in places far away from those functions.
Introduce wrapper functions that allow doing the right thing easily,
and add commentary in hopes of preventing future mistakes from
copy-and-paste of code that's only conditionally safe.
Two actual bugs of this ilk are fixed here. We failed to preprocess
column GENERATED expressions before checking mutability, so that the
code could fail to detect the use of a volatile function
default-argument expression, or it could reject a polymorphic function
that is actually immutable on the datatype of interest. Likewise,
column DEFAULT expressions weren't preprocessed before determining if
it's safe to apply the attmissingval mechanism. A false negative
would just result in an unnecessary table rewrite, but a false
positive could allow the attmissingval mechanism to be used in a case
where it should not be, resulting in unexpected initial values in a
new column.
In passing, re-order the steps in ComputePartitionAttrs so that its
checks for invalid column references are done before applying
expression_planner, rather than after. The previous coding would
not complain if a partition expression contains a disallowed column
reference that gets optimized away by constant folding, which seems
to me to be a behavior we do not want.
Per bug #18097 from Jim Keener. Back-patch to all supported versions.
Discussion: https://postgr.es/m/18097-ebb179674f22932f@postgresql.org
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
In recent releases, such cases fail with "cache lookup failed for
function 0" rather than complaining that the conversion function
doesn't exist as prior versions did. Seems to be a consequence of
sloppy refactoring in commit f82de5c46. Add the missing error check.
Per report from Pierre Fortin. Back-patch to v14 where the
oversight crept in.
Discussion: https://postgr.es/m/20230929163739.3bea46e5.pfortin@pfortin.com
