When a feature enumerates relations and runs functions associated with all found relations, the feature's user shall not need to trust every user having permission to create objects. BRIN-specific functionality in autovacuum neglected to account for this, as did pg_amcheck and CLUSTER. An attacker having permission to create non-temp objects in at least one schema could execute arbitrary SQL functions under the identity of the bootstrap superuser. CREATE INDEX (not a relation-enumerating operation) and REINDEX protected themselves too late. This change extends to the non-enumerating amcheck interface. Back-patch to v10 (all supported versions).
Sergey Shinderuk, reviewed (in earlier versions) by Alexander Lakhin. Reported by Alexander Lakhin.
a117cebd63 Make relation-enumerating operations be security-restricted operations.
contrib/amcheck/expected/check_btree.out | 23 ++++++++
contrib/amcheck/sql/check_btree.sql | 21 +++++++
contrib/amcheck/verify_nbtree.c | 27 +++++++++
src/backend/access/brin/brin.c | 29 +++++++++-
src/backend/catalog/index.c | 65 ++++++++++++++++-----
src/backend/commands/cluster.c | 37 ++++++++----
src/backend/commands/indexcmds.c | 98 +++++++++++++++++++++++++++-----
src/backend/utils/init/miscinit.c | 24 +++++---
src/test/regress/expected/privileges.out | 55 ++++++++++++++++++
src/test/regress/sql/privileges.sql | 47 +++++++++++++++
10 files changed, 378 insertions(+), 48 deletions(-)