postgres-github.git / summary / log / commit / refs

commit    f2081a7800f1696cb0415bacd655cb41b7b9ca63
Author:   Fujii Masao <fujii@postgresql.org>
Date:     Wed Jun 03 09:44:56 2026 +0000

    Fix race in ReplicationSlotRelease() for ephemeral slots
    
    When releasing an ephemeral replication slot, ReplicationSlotRelease()
    drops the slot via ReplicationSlotDropAcquired().
    
    However, after dropping the slot, ReplicationSlotRelease() continued
    to use its local "slot" pointer, which still referenced the dropped
    slot's former shared-memory entry. It could then update fields such as
    effective_xmin in that entry.
    
    Once an ephemeral slot has been dropped (via ReplicationSlotDropAcquired()),
    its slot array entry can be reused immediately by another backend
    creating a new slot. As a result, those updates could corrupt
    the state of an unrelated replication slot.
    
    Fix by skipping those shared-memory updates for phemeral slots and
    performing them only for non-ephemeral slots, whose shared-memory
    entries remain valid after release.
    
    Backpatch to all supported versions.
    
    Author: Zhijie Hou <houzj.fnst@fujitsu.com>
    Reviewed-by: Masao Fujii <masao.fujii@gmail.com>
    Reviewed-by: Srinath Reddy Sadipiralla <srinath2133@gmail.com>
    Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
    Discussion: https://postgr.es/m/TY4PR01MB177184FF9EE916F577E1F554194082@TY4PR01MB17718.jpnprd01.prod.outlook.com
    Backpatch-through: 14