Release date: 2017-05-11
This release contains a variety of fixes from 9.2.20. For information about new features in the 9.2 major release, see Section E.82.
The PostgreSQL community will stop releasing updates for the 9.2.X release series in September 2017. Users are encouraged to update to a newer release branch soon.
A dump/restore is not required for those running 9.2.X.
However, if you use foreign data servers that make use of user passwords for authentication, see the first changelog entry below.
Also, if you are upgrading from a version earlier than 9.2.20, see Section E.62.
Restrict visibility
of pg_user_mappings
.umoptions
, to
protect passwords stored as user mapping options
(Michael Paquier, Feike Steenbergen)
The previous coding allowed the owner of a foreign server object,
or anyone he has granted server USAGE
permission to,
to see the options for all user mappings associated with that server.
This might well include passwords for other users.
Adjust the view definition to match the behavior of
information_schema.user_mapping_options
, namely that
these options are visible to the user being mapped, or if the mapping
is for PUBLIC
and the current user is the server
owner, or if the current user is a superuser.
(CVE-2017-7486)
By itself, this patch will only fix the behavior in newly initdb'd databases. If you wish to apply this change in an existing database, follow the corrected procedure shown in the changelog entry for CVE-2017-7547, in Section E.60.
Prevent exposure of statistical information via leaky operators (Peter Eisentraut)
Some selectivity estimation functions in the planner will apply
user-defined operators to values obtained
from pg_statistic
, such as most common values and
histogram entries. This occurs before table permissions are checked,
so a nefarious user could exploit the behavior to obtain these values
for table columns he does not have permission to read. To fix,
fall back to a default estimate if the operator's implementation
function is not certified leak-proof and the calling user does not have
permission to read the table column whose statistics are needed.
At least one of these criteria is satisfied in most cases in practice.
(CVE-2017-7484)
Fix possible corruption of “init forks” of unlogged indexes (Robert Haas, Michael Paquier)
This could result in an unlogged index being set to an invalid state after a crash and restart. Such a problem would persist until the index was dropped and rebuilt.
Fix incorrect reconstruction of pg_subtrans
entries
when a standby server replays a prepared but uncommitted two-phase
transaction (Tom Lane)
In most cases this turned out to have no visible ill effects, but in
corner cases it could result in circular references
in pg_subtrans
, potentially causing infinite loops
in queries that examine rows modified by the two-phase transaction.
Ensure parsing of queries in extension scripts sees the results of immediately-preceding DDL (Julien Rouhaud, Tom Lane)
Due to lack of a cache flush step between commands in an extension
script file, non-utility queries might not see the effects of an
immediately preceding catalog change, such as ALTER TABLE
... RENAME
.
Skip tablespace privilege checks when ALTER TABLE ... ALTER
COLUMN TYPE
rebuilds an existing index (Noah Misch)
The command failed if the calling user did not currently have
CREATE
privilege for the tablespace containing the index.
That behavior seems unhelpful, so skip the check, allowing the
index to be rebuilt where it is.
Fix ALTER TABLE ... VALIDATE CONSTRAINT
to not recurse
to child tables when the constraint is marked NO INHERIT
(Amit Langote)
This fix prevents unwanted “constraint does not exist” failures when no matching constraint is present in the child tables.
Fix VACUUM
to account properly for pages that could not
be scanned due to conflicting page pins (Andrew Gierth)
This tended to lead to underestimation of the number of tuples in
the table. In the worst case of a small heavily-contended
table, VACUUM
could incorrectly report that the table
contained no tuples, leading to very bad planning choices.
Ensure that bulk-tuple-transfer loops within a hash join are interruptible by query cancel requests (Tom Lane, Thomas Munro)
Fix cursor_to_xml()
to produce valid output
with tableforest
= false
(Thomas Munro, Peter Eisentraut)
Previously it failed to produce a wrapping <table>
element.
Improve performance of pg_timezone_names
view
(Tom Lane, David Rowley)
Fix sloppy handling of corner-case errors from lseek()
and close()
(Tom Lane)
Neither of these system calls are likely to fail in typical situations,
but if they did, fd.c
could get quite confused.
Fix incorrect check for whether postmaster is running as a Windows service (Michael Paquier)
This could result in attempting to write to the event log when that isn't accessible, so that no logging happens at all.
Fix ecpg to support COMMIT PREPARED
and ROLLBACK PREPARED
(Masahiko Sawada)
Fix a double-free error when processing dollar-quoted string literals in ecpg (Michael Meskes)
In pg_dump, fix incorrect schema and owner marking for comments and security labels of some types of database objects (Giuseppe Broccolo, Tom Lane)
In simple cases this caused no ill effects; but for example, a schema-selective restore might omit comments it should include, because they were not marked as belonging to the schema of their associated object.
Avoid emitting an invalid list file in pg_restore -l
when SQL object names contain newlines (Tom Lane)
Replace newlines by spaces, which is sufficient to make the output
valid for pg_restore -L
's purposes.
Fix pg_upgrade to transfer comments and security labels attached to “large objects” (blobs) (Stephen Frost)
Previously, blobs were correctly transferred to the new database, but any comments or security labels attached to them were lost.
Improve error handling
in contrib/adminpack
's pg_file_write()
function (Noah Misch)
Notably, it failed to detect errors reported
by fclose()
.
In contrib/dblink
, avoid leaking the previous unnamed
connection when establishing a new unnamed connection (Joe Conway)
Support OpenSSL 1.1.0 (Heikki Linnakangas, Andreas Karlsson, Tom Lane)
This is a back-patch of work previously done in newer branches; it's needed since many platforms are adopting newer OpenSSL versions.
Support Tcl 8.6 in MSVC builds (Álvaro Herrera)
Sync our copy of the timezone library with IANA release tzcode2017b (Tom Lane)
This fixes a bug affecting some DST transitions in January 2038.
Update time zone data files to tzdata release 2017b for DST law changes in Chile, Haiti, and Mongolia, plus historical corrections for Ecuador, Kazakhstan, Liberia, and Spain. Switch to numeric abbreviations for numerous time zones in South America, the Pacific and Indian oceans, and some Asian and Middle Eastern countries.
The IANA time zone database previously provided textual abbreviations
for all time zones, sometimes making up abbreviations that have little
or no currency among the local population. They are in process of
reversing that policy in favor of using numeric UTC offsets in zones
where there is no evidence of real-world use of an English
abbreviation. At least for the time being, PostgreSQL
will continue to accept such removed abbreviations for timestamp input.
But they will not be shown in the pg_timezone_names
view nor used for output.
Use correct daylight-savings rules for POSIX-style time zone names in MSVC builds (David Rowley)
The Microsoft MSVC build scripts neglected to install
the posixrules
file in the timezone directory tree.
This resulted in the timezone code falling back to its built-in
rule about what DST behavior to assume for a POSIX-style time zone
name. For historical reasons that still corresponds to the DST rules
the USA was using before 2007 (i.e., change on first Sunday in April
and last Sunday in October). With this fix, a POSIX-style zone name
will use the current and historical DST transition dates of
the US/Eastern
zone. If you don't want that, remove
the posixrules
file, or replace it with a copy of some
other zone file (see Section 8.5.3). Note that
due to caching, you may need to restart the server to get such changes
to take effect.