Re: [PATCH] Fix leaky VIEWs for RLS

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
Cc: KaiGai Kohei <kaigai(at)ak(dot)jp(dot)nec(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, marc(at)bloodnok(dot)com, pgsql-hackers(at)postgresql(dot)org
Subject: Re: [PATCH] Fix leaky VIEWs for RLS
Date: 2010-06-04 14:33:57
Message-ID: 2629.1275662037@sss.pgh.pa.us
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Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
> On 04/06/10 07:57, Tom Lane wrote:
>> The proposal some time back in this thread was to trust all built-in
>> functions and no others.

> I thought I debunked that idea already
> (http://archives.postgresql.org/pgsql-hackers/2009-10/msg01428.php). Not
> all built-in functions are safe. Consider casting integer to text, for
> example. Seems innocent at first glance, but it's not; if the input is
> not a valid integer, it throws an error which contains the input string,
> revealing it.

Hmm ... that's a mighty interesting example, because it shows that any
well-meaning change in error handling might render seemingly-unrelated
functions "unsafe". And we're certainly not going to make error
messages stop showing relevant information just because of this.

Maybe the entire idea is unworkable. I certainly don't find any comfort
in your proposal in the above-referenced message to trust index
operators; where is it written that those don't throw errors?

regards, tom lane

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