ALTER SUBSCRIPTION ... REFRESH PUBLICATION may crash if a subscribed table (or sequence) is dropped concurrently.
In check_publications_origin_tables(), the function iterates over subrel_local_oids without holding locks on the individual relations. If a table is dropped by another session between when the OID list was collected and when get_rel_name() is called, it returns NULL. That NULL is then passed to quote_literal_cstr(), which dereferences it unconditionally, causing a segfault. The same pattern exists in
check_publications_origin_sequences() as well.
Attached a patch to fix this by doing a null check after get_rel_name() and get_namespace_name(), and skip the relation if it's gone.
Thanks,
Satya
Hi Satya,
I've reviewed the patch and it looks good, just a small comment - instead of silently continuing after finding a dropped local table, would you want to log an error message?
