E.4. Release 8.2.6

E.4.1. Migration to Version 8.2.6

A dump/restore is not required for those running 8.2.X.

E.4.2. Changes

• Prevent functions in indexes from executing with the privileges of the user running VACUUM, ANALYZE, etc (Tom)

  Functions used in index expressions and partial-index predicates are evaluated whenever a new table entry is made. It has long been understood that this poses a risk of trojan-horse code execution if one modifies a table owned by an untrustworthy user. (Note that triggers, defaults, check constraints, etc. pose the same type of risk.) But functions in indexes pose extra danger because they will be executed by routine maintenance operations such as VACUUM FULL, which are commonly performed automatically under a superuser account. For example, a nefarious user can execute code with superuser privileges by setting up a trojan-horse index definition and waiting for the next routine vacuum. The fix arranges for standard maintenance operations (including VACUUM, ANALYZE, REINDEX, and CLUSTER) to execute as the table owner rather than the calling user, using the same privilege-switching mechanism already used for SECURITY DEFINER functions. To prevent bypassing this security measure, execution of SET SESSION AUTHORIZATION and SET ROLE is now forbidden within a SECURITY DEFINER context. (CVE-2007-6600)

• Repair assorted bugs in the regular-expression package (Tom, Will Drewry)

  Suitably crafted regular-expression patterns could cause crashes, infinite or near-infinite looping, and/or massive memory consumption, all of which pose denial-of-service hazards for applications that accept regex search patterns from untrustworthy sources. (CVE-2007-4769, CVE-2007-4772, CVE-2007-6067)

• Require non-superusers who use /contrib/dblink to use only password authentication, as a security measure (Joe)

  The fix that appeared for this in 8.2.5 was incomplete, as it plugged the hole for only some dblink functions. (CVE-2007-6601, CVE-2007-3278)

• Fix bugs in WAL replay for GIN indexes (Teodor)

• Fix GIN index build to work properly when maintenance_work_mem is 4GB or more (Tom)

• Update time zone data files to tzdata release 2007k (in particular, recent Argentina changes) (Tom)

• Improve planner's handling of LIKE/regex estimation in non-C locales (Tom)

• Fix planning-speed problem for deep outer-join nests, as well as possible poor choice of join order (Tom)

• Fix planner failure in some cases of WHERE false AND var IN (SELECT ...) (Tom)

• Make CREATE TABLE ... SERIAL and ALTER SEQUENCE ... OWNED BY not change the currval() state of the sequence (Tom)

• Preserve the tablespace and storage parameters of indexes that are rebuilt by ALTER TABLE ... ALTER COLUMN TYPE (Tom)

• Make archive recovery always start a new WAL timeline, rather than only when a recovery stop time was used (Simon)

  This avoids a corner-case risk of trying to overwrite an existing archived copy of the last WAL segment, and seems simpler and cleaner than the original definition.

• Make VACUUM not use all of maintenance_work_mem when the table is too small for it to be useful (Alvaro)

• Fix potential crash in translate() when using a multibyte database encoding (Tom)

• Make corr() return the correct result for negative correlation values (Neil)

• Fix overflow in extract(epoch from interval) for intervals exceeding 68 years (Tom)

• Fix PL/Perl to not fail when a UTF-8 regular expression is used in a trusted function (Andrew)

• Fix PL/Perl to cope when platform's Perl defines type bool as int rather than char (Tom)

  While this could theoretically happen anywhere, no standard build of Perl did things this way ... until Mac OS X 10.5.

• Fix PL/Python to work correctly with Python 2.5 on 64-bit machines (Marko Kreen)

• Fix PL/Python to not crash on long exception messages (Alvaro)

• Fix pg_dump to correctly handle inheritance child tables that have default expressions different from their parent's (Tom)

• Fix libpq crash when PGPASSFILE refers to a file that is not a plain file (Martin Pitt)

• ecpg parser fixes (Michael)

• Make contrib/pgcrypto defend against OpenSSL libraries that fail on keys longer than 128 bits; which is the case at least on some Solaris versions (Marko Kreen)

• Make contrib/tablefunc's crosstab() handle NULL rowid as a category in its own right, rather than crashing (Joe)

• Fix tsvector and tsquery output routines to escape backslashes correctly (Teodor, Bruce)

• Fix crash of to_tsvector() on huge input strings (Teodor)

• Require a specific version of Autoconf to be used when re-generating the configure script (Peter)

  This affects developers and packagers only. The change was made to prevent accidental use of untested combinations of Autoconf and PostgreSQL versions. You can remove the version check if you really want to use a different Autoconf version, but it's your responsibility whether the result works or not.

• Update gettimeofday configuration check so that PostgreSQL can be built on newer versions of MinGW (Magnus)