Security implications of (plpgsql) functions

CREATE FUNCTION "x" (integer) RETURNS integer AS '
BEGIN
    RETURN x(0);
END' LANGUAGE 'plpgsql' WITH ( isstrict );
SELECT x(0);
server closed the connection unexpectedly
        This probably means the server terminated abnormally
        before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!>

The log says:
 DEBUG:  server process (pid 3550) was terminated by signal 11
 DEBUG:  terminating any other active server processes

The thing that worries me most is the last message: postmaster terminates all
other backends, therefore overflowing the stack via a plpgsql function can be
used to DoS-attack the server.

Is there anything one (as a postgresql installation admin) can do?  Disabling
procedural languages in databases of the users I don't trust comes to mind, but
does it really make me safe? I mean: won't such attack still be possible with
pure SQL?

regards,

Marcin
--
Marcin Owsiany <marcin@owsiany.pl>              http://marcin.owsiany.pl/
GnuPG: 1024D/60F41216  FE67 DA2D 0ACA FC5E 3F75  D6F6 3A0D 8AA0 60F4 1216

"Every program in development at MIT expands until it can read mail."
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