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(at)owsiany(dot)pl> http://marcin.owsiany.pl/
GnuPG: 1024D/60F41216 FE67 DA2D 0ACA FC5E 3F75 D6F6 3A0D 8AA0 60F4 1216

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