Use a separate interpreter for each calling SQL userid in PL/Perl and
PL/Tcl (Tom Lane)
This change prevents security problems that can be caused by subverting
Perl or Tcl code that will be executed later in the same session under
another SQL user identity (for example, within a SECURITY
DEFINER function). Most scripting languages offer numerous ways that
that might be done, such as redefining standard functions or operators
called by the target function. Without this change, any SQL user with
Perl or Tcl language usage rights can do essentially anything with the
SQL privileges of the target function's owner.
The cost of this change is that intentional communication among Perl
and Tcl functions becomes more difficult. To provide an escape hatch,
PL/PerlU and PL/TclU functions continue to use only one interpreter
per session. This is not considered a security issue since all such
functions execute at the trust level of a database superuser already.
It is likely that third-party procedural languages that claim to offer
trusted execution have similar security issues. We advise contacting
the authors of any PL you are depending on for security-critical
purposes.
Our thanks to Tim Bunce for pointing out this issue (CVE-2010-3433).
Improve pg_get_expr() security fix so that the function
can still be used on the output of a sub-select (Tom Lane)
Fix incorrect placement of placeholder evaluation (Tom Lane)
This bug could result in query outputs being non-null when they
should be null, in cases where the inner side of an outer join
is a sub-select with non-strict expressions in its output list.
Fix join removal's handling of placeholder expressions (Tom Lane)
Fix possible duplicate scans of UNION ALL member relations
(Tom Lane)
Prevent infinite loop in ProcessIncomingNotify() after unlistening
(Jeff Davis)
Prevent show_session_authorization() from crashing within autovacuum
processes (Tom Lane)
Re-allow input of Julian dates prior to 0001-01-01 AD (Tom Lane)
Input such as 'J100000'::date worked before 8.4,
but was unintentionally broken by added error-checking.
Make psql recognize DISCARD ALL as a command that should
not be encased in a transaction block in autocommit-off mode
(Itagaki Takahiro)
Update build infrastructure and documentation to reflect the source code
repository's move from CVS to Git (Magnus Hagander and others)