[SECURITY] [DLA-432-1] postgresql-8.4 update

Package : postgresql-8.4
Version : 8.4.22lts6-0+deb6u1

Several bugs were discovered in PostgreSQL, a relational database server
system. The 8.4 branch is EOLed upstream, but still present in Debian squeeze.
This new LTS minor version contains fixes that were applied upstream to the
9.1.20 version, backported to 8.4.22 which was the last version officially
released by the PostgreSQL developers. This LTS effort for squeeze-lts is a
community project sponsored by credativ GmbH.

This release is the last LTS update for PostgreSQL 8.4. Users should
migrate to a newer PostgreSQL at the earliest opportunity.

Migration to Version 8.4.22lts6

A dump/restore is not required for those running 8.4.X. However, if you are
upgrading from a version earlier than 8.4.22, see the relevant release notes.

Fixes

Fix infinite loops and buffer-overrun problems in regular expressions
(Tom Lane)

Very large character ranges in bracket expressions could cause
infinite loops in some cases, and memory overwrites in other cases.
(CVE-2016-0773)

Perform an immediate shutdown if the postmaster.pid file is removed
(Tom Lane)

The postmaster now checks every minute or so that postmaster.pid is
still there and still contains its own PID. If not, it performs an
immediate shutdown, as though it had received SIGQUIT. The main
motivation for this change is to ensure that failed buildfarm runs
will get cleaned up without manual intervention; but it also serves
to limit the bad effects if a DBA forcibly removes postmaster.pid
and then starts a new postmaster.