E.75.1. Migration to Version 8.3.18

A dump/restore is not required for those running 8.3.X.

However, if you are upgrading from a version earlier than 8.3.17, see Section E.76.

E.75.2. Changes

• Require execute permission on the trigger function for CREATE TRIGGER (Robert Haas)

  This missing check could allow another user to execute a trigger function with forged input data, by installing it on a table he owns. This is only of significance for trigger functions marked SECURITY DEFINER, since otherwise trigger functions run as the table owner anyway. (CVE-2012-0866)

• Convert newlines to spaces in names written in pg_dump comments (Robert Haas)

  pg_dump was incautious about sanitizing object names that are emitted within SQL comments in its output script. A name containing a newline would at least render the script syntactically incorrect. Maliciously crafted object names could present a SQL injection risk when the script is reloaded. (CVE-2012-0868)

• Fix btree index corruption from insertions concurrent with vacuuming (Tom Lane)

  An index page split caused by an insertion could sometimes cause a concurrently-running VACUUM to miss removing index entries that it should remove. After the corresponding table rows are removed, the dangling index entries would cause errors (such as "could not read block N in file ...") or worse, silently wrong query results after unrelated rows are re-inserted at the now-free table locations. This bug has been present since release 8.2, but occurs so infrequently that it was not diagnosed until now. If you have reason to suspect that it has happened in your database, reindexing the affected index will fix things.

• Allow non-existent values for some settings in ALTER USER/DATABASE SET (Heikki Linnakangas)

  Allow default_text_search_config, default_tablespace, and temp_tablespaces to be set to names that are not known. This is because they might be known in another database where the setting is intended to be used, or for the tablespace cases because the tablespace might not be created yet. The same issue was previously recognized for search_path, and these settings now act like that one.

• Track the OID counter correctly during WAL replay, even when it wraps around (Tom Lane)

  Previously the OID counter would remain stuck at a high value until the system exited replay mode. The practical consequences of that are usually nil, but there are scenarios wherein a standby server that's been promoted to master might take a long time to advance the OID counter to a reasonable value once values are needed.

• Fix regular expression back-references with * attached (Tom Lane)

  Rather than enforcing an exact string match, the code would effectively accept any string that satisfies the pattern sub-expression referenced by the back-reference symbol.

  A similar problem still afflicts back-references that are embedded in a larger quantified expression, rather than being the immediate subject of the quantifier. This will be addressed in a future PostgreSQL release.

• Fix recently-introduced memory leak in processing of inet/cidr values (Heikki Linnakangas)

  A patch in the December 2011 releases of PostgreSQL caused memory leakage in these operations, which could be significant in scenarios such as building a btree index on such a column.

• Avoid double close of file handle in syslogger on Windows (MauMau)

  Ordinarily this error was invisible, but it would cause an exception when running on a debug version of Windows.

• Fix I/O-conversion-related memory leaks in plpgsql (Andres Freund, Jan Urbanski, Tom Lane)

  Certain operations would leak memory until the end of the current function.

• Improve pg_dump's handling of inherited table columns (Tom Lane)

  pg_dump mishandled situations where a child column has a different default expression than its parent column. If the default is textually identical to the parent's default, but not actually the same (for instance, because of schema search path differences) it would not be recognized as different, so that after dump and restore the child would be allowed to inherit the parent's default. Child columns that are NOT NULL where their parent is not could also be restored subtly incorrectly.

• Fix pg_restore's direct-to-database mode for INSERT-style table data (Tom Lane)

  Direct-to-database restores from archive files made with --inserts or --column-inserts options fail when using pg_restore from a release dated September or December 2011, as a result of an oversight in a fix for another problem. The archive file itself is not at fault, and text-mode output is okay.

• Fix error in contrib/intarray's int[] & int[] operator (Guillaume Lelarge)

  If the smallest integer the two input arrays have in common is 1, and there are smaller values in either array, then 1 would be incorrectly omitted from the result.

• Fix error detection in contrib/pgcrypto's encrypt_iv() and decrypt_iv() (Marko Kreen)

  These functions failed to report certain types of invalid-input errors, and would instead return random garbage values for incorrect input.

• Fix one-byte buffer overrun in contrib/test_parser (Paul Guyot)

  The code would try to read one more byte than it should, which would crash in corner cases. Since contrib/test_parser is only example code, this is not a security issue in itself, but bad example code is still bad.

• Use __sync_lock_test_and_set() for spinlocks on ARM, if available (Martin Pitt)

  This function replaces our previous use of the SWPB instruction, which is deprecated and not available on ARMv6 and later. Reports suggest that the old code doesn't fail in an obvious way on recent ARM boards, but simply doesn't interlock concurrent accesses, leading to bizarre failures in multiprocess operation.

• Use -fexcess-precision=standard option when building with gcc versions that accept it (Andrew Dunstan)

  This prevents assorted scenarios wherein recent versions of gcc will produce creative results.

• Allow use of threaded Python on FreeBSD (Chris Rees)

  Our configure script previously believed that this combination wouldn't work; but FreeBSD fixed the problem, so remove that error check.