Release date: 2015-05-22
This release contains a variety of fixes from 9.3.6. For information about new features in the 9.3 major release, see Section E.84.
A dump/restore is not required for those running 9.3.X.
However, if you use
regexp_matches() functions, see the changelog
entry below about that.
Also, if you are upgrading from a version earlier than 9.3.6, see Section E.78.
Avoid possible crash when client disconnects just before the authentication timeout expires (Benkocs Norbert Attila)
If the timeout interrupt fired partway through the session shutdown sequence, SSL-related state would be freed twice, typically causing a crash and hence denial of service to other sessions. Experimentation shows that an unauthenticated remote attacker could trigger the bug somewhat consistently, hence treat as security issue. (CVE-2015-3165)
Improve detection of system-call failures (Noah Misch)
Our replacement implementation of
snprintf() failed to check for errors
reported by the underlying system library calls; the main
case that might be missed is out-of-memory situations. In
the worst case this might lead to information exposure,
due to our code assuming that a buffer had been
overwritten when it hadn't been. Also, there were a few
places in which security-relevant calls of other system
library functions did not check for failure.
It remains possible that some calls of the
*printf() family of
functions are vulnerable to information disclosure if an
out-of-memory error occurs at just the wrong time. We
judge the risk to not be large, but will continue
analysis in this area. (CVE-2015-3166)
uniformly report decryption failures as “Wrong key or corrupt
data” (Noah Misch)
Previously, some cases of decryption with an incorrect
key could report other error message texts. It has been
shown that such variance in error reports can aid
attackers in recovering keys from other systems. While
it's unknown whether
pgcrypto's specific behaviors are
likewise exploitable, it seems better to avoid the risk
by using a one-size-fits-all message. (CVE-2015-3167)
Protect against wraparound of multixact member IDs (Álvaro Herrera, Robert Haas, Thomas Munro)
Under certain usage patterns, the existing defenses
against this might be insufficient, allowing
pg_multixact/members files to be
removed too early, resulting in data loss. The fix for
this includes modifying the server to fail transactions
that would result in overwriting old multixact member ID
data, and improving autovacuum to ensure it will act
proactively to prevent multixact member ID wraparound, as
it does for transaction ID wraparound.
Fix incorrect declaration of
regexp_matches() functions (Tom
These functions should return
text, like the core functions they are wrappers
for; but they were incorrectly declared as returning just
text. This mistake had two
results: first, if there was no match you got a scalar
null result, whereas what you should get is an empty set
(zero rows). Second, the
flag was effectively ignored, since you would get only
one result array even if there were multiple matches.
While the latter behavior is clearly a bug, there
might be applications depending on the former behavior;
therefore the function declarations will not be changed
by default until PostgreSQL 9.5. In pre-9.5 branches,
the old behavior exists in version 1.0 of the
citext extension, while we
have provided corrected declarations in version 1.1
(which is not
installed by default). To adopt the fix in pre-9.5
citext UPDATE TO '1.1' in each database in which
citext is installed. (You
can also “update” back to 1.0 if you need to
undo that.) Be aware that either update direction will
require dropping and recreating any views or rules that
Fix incorrect checking of deferred exclusion constraints after a HOT update (Tom Lane)
If a new row that potentially violates a deferred exclusion constraint is HOT-updated (that is, no indexed columns change and the row can be stored back onto the same table page) later in the same transaction, the exclusion constraint would be reported as violated when the check finally occurred, even if the row(s) the new row originally conflicted with had been deleted.
Fix planning of star-schema-style queries (Tom Lane)
Sometimes, efficient scanning of a large table requires that index parameters be provided from more than one other table (commonly, dimension tables whose keys are needed to index a large fact table). The planner should be able to find such plans, but an overly restrictive search heuristic prevented it.
Prevent improper reordering of antijoins (NOT EXISTS joins) versus other outer joins (Tom Lane)
This oversight in the planner has been observed to cause “could not find RelOptInfo for given relids” errors, but it seems possible that sometimes an incorrect query plan might get past that consistency check and result in silently-wrong query output.
Fix incorrect matching of subexpressions in outer-join plan nodes (Tom Lane)
Previously, if textually identical non-strict subexpressions were used both above and below an outer join, the planner might try to re-use the value computed below the join, which would be incorrect because the executor would force the value to NULL in case of an unmatched outer row.
Fix GEQO planner to cope with failure of its join order heuristic (Tom Lane)
This oversight has been seen to lead to “failed to join all relations
together” errors in queries involving
LATERAL, and that might
happen in other cases as well.
Fix possible deadlock at startup when
max_prepared_transactions is too small
Don't archive useless preallocated WAL files after a timeline switch (Heikki Linnakangas)
data directory after a crash (Abhijit Menon-Sen, Robert
This ensures consistency if another crash occurs shortly later. (The second crash would have to be a system-level crash, not just a database crash, for there to be a problem.)
Fix autovacuum launcher's possible failure to shut down, if an error occurs after it receives SIGTERM (Álvaro Herrera)
Cope with unexpected signals in
This oversight could result in spurious errors about “multiple backends attempting to wait for pincount 1”.
Fix crash when doing
IN to a table with check constraints that contain
whole-row references (Tom Lane)
The known failure case only crashes in 9.4 and up, but there is very similar code in 9.3 and 9.2, so back-patch those branches as well.
Avoid waiting for WAL flush or synchronous replication during commit of a transaction that was read-only so far as the user is concerned (Andres Freund)
Previously, a delay could occur at commit in transactions that had written WAL due to HOT page pruning, leading to undesirable effects such as sessions getting stuck at startup if all synchronous replicas are down. Sessions have also been observed to get stuck in catchup interrupt processing when using synchronous replication; this will fix that problem as well.
Fix crash when manipulating hash indexes on temporary tables (Heikki Linnakangas)
Fix possible failure during hash index bucket split, if other processes are modifying the index concurrently (Tom Lane)
Check for interrupts while analyzing index expressions (Jeff Janes)
ANALYZE executes index
expressions many times; if there are slow functions in
such an expression, it's desirable to be able to cancel
ANALYZE before that loop
tableoid of a
foreign table is reported correctly when a
READ COMMITTED recheck occurs after
locking rows in
DELETE (Etsuro Fujita)
Add the name of the target server to object description strings for foreign-server user mappings (Álvaro Herrera)
Include the schema name in object identity strings for conversions (Álvaro Herrera)
include_realm to 1 when using
Kerberos/GSSAPI/SSPI authentication (Stephen Frost)
Without this, identically-named users from different realms cannot be distinguished. For the moment this is only a documentation change, but it will become the default setting in PostgreSQL 9.5.
Remove code for matching IPv4
pg_hba.conf entries to IPv4-in-IPv6
addresses (Tom Lane)
This hack was added in 2003 in response to a report
that some Linux kernels of the time would report IPv4
connections as having IPv4-in-IPv6 addresses. However,
the logic was accidentally broken in 9.0. The lack of any
field complaints since then shows that it's not needed
anymore. Now we have reports that the broken code causes
crashes on some systems, so let's just remove it rather
than fix it. (Had we chosen to fix it, that would make
for a subtle and potentially security-sensitive change in
the effective meaning of IPv4
pg_hba.conf entries, which does not
seem like a good thing to do in minor releases.)
Report WAL flush, not insert, position in
IDENTIFY_SYSTEM replication command
This avoids a possible startup failure in pg_receivexlog.
While shutting down service on Windows, periodically send status updates to the Service Control Manager to prevent it from killing the service too soon; and ensure that pg_ctl will wait for shutdown (Krystian Bigaj)
Reduce risk of network deadlock when using libpq's non-blocking mode (Heikki Linnakangas)
When sending large volumes of data, it's important to
drain the input buffer every so often, in case the server
has sent enough response data to cause it to block on
output. (A typical scenario is that the server is sending
a stream of NOTICE messages during
COPY FROM STDIN.) This worked properly
in the normal blocking mode, but not so much in
non-blocking mode. We've modified libpq to opportunistically drain
input when it can, but a full defense against this
problem requires application cooperation: the application
should watch for socket read-ready as well as write-ready
conditions, and be sure to call
PQconsumeInput() upon read-ready.
In libpq, fix misparsing of empty values in URI connection strings (Thomas Fanghaenel)
Fix array handling in ecpg (Michael Meskes)
Fix psql to sanely
handle URIs and conninfo strings as the first parameter
\connect (David Fetter,
Andrew Dunstan, Álvaro Herrera)
This syntax has been accepted (but undocumented) for a long time, but previously some parameters might be taken from the old connection instead of the given string, which was agreed to be undesirable.
Suppress incorrect complaints from psql on some platforms that it
failed to write
~/.psql_history at exit (Tom Lane)
This misbehavior was caused by a workaround for a bug in very old (pre-2006) versions of libedit. We fixed it by removing the workaround, which will cause a similar failure to appear for anyone still using such versions of libedit. Recommendation: upgrade that library, or use libreadline.
Fix pg_dump's rule for deciding which casts are system-provided casts that should not be dumped (Tom Lane)
In pg_dump, fix
failure to honor
compression level option together with
-Fd (Michael Paquier)
Make pg_dump consider foreign key relationships between extension configuration tables while choosing dump order (Gilles Darold, Michael Paquier, Stephen Frost)
This oversight could result in producing dumps that fail to reload because foreign key constraints are transiently violated.
Avoid possible pg_dump failure when concurrent sessions are creating and dropping temporary functions (Tom Lane)
Fix dumping of views that are just
VALUES(...) but have column aliases (Tom
In pg_upgrade, force timeline 1 in the new cluster (Bruce Momjian)
This change prevents upgrade failures caused by bogus complaints about missing WAL history files.
In pg_upgrade, check for improperly non-connectable databases before proceeding (Bruce Momjian)
In pg_upgrade, quote
directory paths properly in the generated
delete_old_cluster script (Bruce
In pg_upgrade, preserve database-level freezing info properly (Bruce Momjian)
This oversight could cause missing-clog-file errors
for tables within the
Run pg_upgrade and pg_resetxlog with restricted privileges on Windows, so that they don't fail when run by an administrator (Muhammad Asif Naeem)
Improve handling of
readdir() failures when scanning
directories in initdb
and pg_basebackup (Marco
Fix slow sorting algorithm in
contrib/intarray (Tom Lane)
Fix compile failure on Sparc V8 machines (Rob Rowan)
Silence some build warnings on macOS (Tom Lane)
Update time zone data files to tzdata release 2015d for DST law changes in Egypt, Mongolia, and Palestine, plus historical changes in Canada and Chile. Also adopt revised zone abbreviations for the America/Adak zone (HST/HDT not HAST/HADT).
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