From 09620ea09121b66e9372e8e9244d8bb6b19b89d7 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Fri, 27 Sep 2024 09:40:09 +0900 Subject: [PATCH] Fix incorrect memory access in VACUUM FULL with invalid toast indexes An invalid toast index is skipped in reindex_relation(). These would be remnants of a failed REINDEX CONCURRENTLY and they should never been rebuilt as there can only be one valid toast index at a time. REINDEX_REL_SUPPRESS_INDEX_USE, used by CLUSTER and VACUUM FULL, needs to maintain a list of the indexes being processed. The list of indexes is retrieved from the relation cache, and includes invalid indexes. The code has missed that invalid toast indexes are ignored in reindex_relation() as this leads to a hard failure in reindex_index(), and they were left in the reindex pending list, making the list inconsistent when rechecked. The incorrect memory access was happening when scanning pg_class for the refresh of pg_database.datfrozenxid, when doing a scan of pg_class. This issue exists since REINDEX CONCURRENTLY exists, where invalid toast indexes can exist, so backpatch all the way down. Reported-by: Alexander Lakhin Author: Tender Wang Discussion: https://postgr.es/m/18630-9aed99c38830657d@postgresql.org Backpatch-through: 12 --- src/backend/catalog/index.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index cecee93ad8e..6084dfa97cb 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -4010,6 +4010,14 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags, errmsg("cannot reindex invalid index \"%s.%s\" on TOAST table, skipping", get_namespace_name(indexNamespaceId), get_rel_name(indexOid)))); + + /* + * Remove this invalid toast index from the reindex pending list, + * as it is skipped here due to the hard failure that would happen + * in reindex_index(), should we try to process it. + */ + if (flags & REINDEX_REL_SUPPRESS_INDEX_USE) + RemoveReindexPending(indexOid); continue; }