Re: [PoC] pg_upgrade: allow to upgrade publisher node - Mailing list pgsql-hackers

On Wed, Sep 20, 2023 at 11:00 AM Hayato Kuroda (Fujitsu)
<kuroda.hayato@fujitsu.com> wrote:
>
> Dear Amit,

+int
+count_old_cluster_logical_slots(void)
+{
+ int dbnum;
+ int slot_count = 0;
+
+ for (dbnum = 0; dbnum < old_cluster.dbarr.ndbs; dbnum++)
+ slot_count += old_cluster.dbarr.dbs[dbnum].slot_arr.nslots;
+
+ return slot_count;
+}

In this code, aren't we assuming that 'slot_arr.nslots' will be zero
for versions <=PG16? On my Windows machine, this value is not zero but
rather some uninitialized negative value which makes its caller try to
allocate some undefined memory and fail. I think you need to
initialize this in get_old_cluster_logical_slot_infos() for lower
versions.

--
With Regards,
Amit Kapila.