pgsql: Prevent privilege escalation in explicit calls to PL validators.

Prevent privilege escalation in explicit calls to PL validators.

The primary role of PL validators is to be called implicitly during
CREATE FUNCTION, but they are also normal functions that a user can call
explicitly.  Add a permissions check to each validator to ensure that a
user cannot use explicit validator calls to achieve things he could not
otherwise achieve.  Back-patch to 8.4 (all supported versions).
Non-core procedural language extensions ought to make the same two-line
change to their own validators.

Andres Freund, reviewed by Tom Lane and Noah Misch.

Security: CVE-2014-0061

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/537cbd35c893e67a63c59bc636c3e888bd228bc7

Modified Files
--------------
doc/src/sgml/plhandler.sgml         |    5 ++-
src/backend/catalog/pg_proc.c       |    9 ++++
src/backend/commands/functioncmds.c |    1 -
src/backend/utils/fmgr/fmgr.c       |   84 +++++++++++++++++++++++++++++++++++
src/include/fmgr.h                  |    1 +
src/pl/plperl/plperl.c              |    4 ++
src/pl/plpgsql/src/pl_handler.c     |    3 ++
src/pl/plpython/plpy_main.c         |    4 ++
8 files changed, 109 insertions(+), 2 deletions(-)