Re: Fwd: Unprivileged user can induce crash by using an SUSET param in PGOPTIONS

On Thu, Jul 21, 2022 at 07:30:20PM -0400, Tom Lane wrote:
> Nathan Bossart <nathandbossart@gmail.com> writes:
>> +    StartTransactionCommand();
>>      process_session_preload_libraries();
>> +    CommitTransactionCommand();
> 
> Yeah, that way would avoid any questions about changing the order of
> operations, but it seems like a mighty expensive solution: it's
> adding a transaction to each backend start on the off chance that
> (a) session_preload_libraries/local_preload_libraries is nonempty and
> (b) the loaded libraries are going to do anything where it'd matter.
> So that's why I thought of moving the call inside a pre-existing
> transaction.
> 
> If we had to back-patch this into any released versions, I'd agree with
> taking the performance hit in order to reduce the chance of side-effects.
> But I think as long as we only have to do it in v15, it's not too late to
> possibly cause some compatibility issues for extensions.

Yeah, fair point.

-- 
Nathan Bossart
Amazon Web Services: https://aws.amazon.com