Re: Cross-backend signals and administration (Was: Re: pg_terminate_backend for same-role)

"Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
> Andres Freund <andres@anarazel.de> wrote:
>> On Tuesday, March 27, 2012 07:51:59 PM Kevin Grittner wrote:
>>> As Tom pointed out, if there's another person sharing the user ID
>>> you're using, and you don't trust them, their ability to cancel
>>> your session is likely way down the list of concerns you should
>>> have.

>> Hm. I don't think that is an entirely valid argumentation. The
>> same user could have entirely different databases. They even could
>> have distinct access countrol via the clients ip.
>> I have seen the same cluster being used for prod/test instances at
>> smaller shops several times. 
>> 
>> Whether thats a valid usecase I have no idea.
> Well, that does sort of leave an arguable vulnerability.  Should the
> same user only be allowed to kill the process from a connection to
> the same database?

I don't see a lot of merit in this argument either.  If joeseviltwin
can connect as joe to database A, he can also connect as joe to
database B in the same cluster, and then do whatever damage he wants.

Fundamentally, if two users are sharing the same userid, *they are the
same user* as far as Postgres is concerned.  It's just silly to make
protection decisions on the assumption that they might not be.
If a DBA does not like the consequences of that, the solution is
obvious.
        regards, tom lane