Re: BUG #15144: *** glibc detected *** postgres: postgres smsconsole [local] SELECT: double free or corruption (!pre

Hello, Peter.

Pgpool used only from App side at another server.

Zabbix running its queries directly at database server.

16.04.2018, 21:03, "Peter Geoghegan" <pg(at)bowt(dot)ie>:
> On Mon, Apr 16, 2018 at 10:48 AM, Alvaro Herrera
> <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
>>  and tuplestore_end does this:
>>          if (state->myfile)
>>                  BufFileClose(state->myfile);
>>  without setting anything in state to NULL; so we're relying on the
>>  caller fs->tstore to null to avoid repeated tuplestore_end calls. I
>>  can't see any way for this to misbehave, but maybe the funcstate appears
>>  more than once in the PerFuncState array, and we clean it correctly the
>>  first time around and then invoke the tuplestore_end() the second time
>>  to the memory that was previously freed? I think this makes no sense
>>  unless we share FunctionScanPerFuncState elements -- do we?
>
> I have no reason to think that we do. Offhand, I find it more likely
> that some executor slot that imagines that it owns the tuple frees the
> tuple once, which is followed by a call to tuplestore_end() that frees
> the same tuple a second time (a double-free). As I mentioned, we've
> seen several bugs of that general variety in both tuplestore and
> tuplesort in the past. Some of these have been very subtle.
>
> Note that pgpool is involved here. I don't know much about pgpool, and
> maybe that's totally irrelevant.
>
> --
> Peter Geoghegan