Re: Use-after-free issue in postgres_fdw

Hi,

On 19/03/26 11:56, Etsuro Fujita wrote:
> I think the root cause is that it is too early to free the PGconn in
> pgfdw_reject_incomplete_xact_state_change() even if the connection is
> in a state where we cannot use it any further; I think we should delay
> that until abort cleanup (ie, pgfdw_xact_callback()). Attached is a
> patch for that.
>

IIUC, with this patch, disconnect_pg_server() will be called at
pgfdw_xact_callback() via pgfdw_reset_xact_state() when the top level
transaction is rollback right?

I've tested and it seems to fix the issue, when "close c1;" is
executed "conn" points to a valid connection pointer and this
connection is properly disconnected when the top level transactions is
rollback.

This issue is reproducible on v14, so I think that we need a back-port.

--
Matheus Alcantara
EDB: https://www.enterprisedb.com