af6ee5e8d4
It's not very sensible to set such attributes on a handler function; but if one were to do so, fmgr.c went into infinite recursion because it would call fmgr_security_definer instead of the handler function proper. There is no way for fmgr_security_definer to know that it ought to call the handler and not the original function referenced by the FmgrInfo's fn_oid, so it tries to do the latter, causing the whole process to start over again. Ordinarily such misconfiguration of a procedural language's handler could be written off as superuser error. However, because we allow non-superuser database owners to create procedural languages and the handler for such a language becomes owned by the database owner, it is possible for a database owner to crash the backend, which ideally shouldn't be possible without superuser privileges. In 9.2 and up we will adjust things so that the handler functions are always owned by superusers, but in existing branches this is a minor security fix. Problem noted by Noah Misch (after several of us had failed to detect it :-(). This is CVE-2012-2655.
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: http://www.postgresql.org/download See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Changes between all PostgreSQL releases are recorded in the file HISTORY. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at http://www.postgresql.org/download/. For more information look at our web site located at http://www.postgresql.org/.