Re: Streaming replication as a separate permissions

On Thu, Dec 23, 2010 at 16:15, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Magnus Hagander <magnus(at)hagander(dot)net> writes:
>> Here's a patch that changes walsender to require a special privilege
>> for replication instead of relying on superuser permissions. We
>> discussed this back before 9.0 was finalized, but IIRC we ran out of
>> time. The motivation being that you really want to use superuser as
>> little as possible - and since being a replication slave is a read
>> only role, it shouldn't require the maximum permission available in
>> the system.
>
> Maybe it needn't require "max" permissions, but one of the motivations
> for requiring superusernesss was to prevent Joe User from sucking every
> last byte of data out of your database (and into someplace he could
> examine it at leisure).  This patch opens that barn door wide, because
> so far as I can see, it allows anybody at all to grant the replication
> privilege ... or revoke it, thereby breaking your replication setup.
> I think only superusers should be allowed to change the flag.

That was certainly not intentional - and doesn't work that way for me
at least, unless I broke it right before I submitted it.

oh hang on.. Yeah, it's allowing anybody *that has CREATE ROLE*
privilege to do it, I think. And I agree that's wrong and should be
fixed. But I can't see it allowing anybody at all to do it - am I
misreading the code?

--
 Magnus Hagander
 Me: http://www.hagander.net/
 Work: http://www.redpill-linpro.com/