From 3982630f7403a12a17e298becb0bf92ac400de1b Mon Sep 17 00:00:00 2001 From: Jim Jones Date: Mon, 2 Nov 2026 10:18:29 +0100 Subject: [PATCH v4 5/6] pg_visibility: Reject temporary tables of other sessions pg_visibility cannot see the pages of another session's temporary table, but it did not reject such tables, so some of its functions returned wrong results or modified that session's visibility map. Report an error instead. Author: Jim Jones Reported-by: Michael Paquier Reviewed-by: Surya Poondla --- contrib/pg_visibility/pg_visibility.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/contrib/pg_visibility/pg_visibility.c b/contrib/pg_visibility/pg_visibility.c index 4195aeacc2a..86528cacaa2 100644 --- a/contrib/pg_visibility/pg_visibility.c +++ b/contrib/pg_visibility/pg_visibility.c @@ -931,6 +931,16 @@ check_relation_relkind(Relation rel) RelationGetRelationName(rel)), errdetail_relkind_not_supported(rel->rd_rel->relkind))); + /* + * Reject attempts to read non-local temporary relations; we would be + * likely to get wrong data since we have no visibility into the owning + * session's local buffers. + */ + if (RELATION_IS_OTHER_TEMP(rel)) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot access temporary tables of other sessions"))); + /* Temporary and unlogged relations are inaccessible during recovery. */ if (!RelationIsPermanent(rel) && RecoveryInProgress()) ereport(ERROR, -- 2.56.0