pgsql: Check for USAGE privilege on types used by stored expressions.

Check for USAGE privilege on types used by stored expressions.

This omission allowed roles without USAGE on a type to create
stored expressions that depend on it, which could prevent the owner
from changing the type later.

The checks deliberately live in the command paths rather than the
dependency-recording routines. Those routines also run whenever
the server re-derives an existing expression, and re-checking there
would break routine maintenance for an owner who has since lost
USAGE on a type its objects already reference. (Checking in the
dependency-recording routines would also require additional
CommandCounterIncrement() calls to avoid spurious errors.)

The addition of a parameter to AlterDomainAddConstraint() breaks
ABI compatibility, but we are unaware of any impacted third-party
code.

Reported-by: Noah Misch <noah(at)leadboat(dot)com>
Author: Nathan Bossart <nathandbossart(at)gmail(dot)com>
Reviewed-by: Noah Misch <noah(at)leadboat(dot)com>
Reviewed-by: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Reviewed-by: Robert Haas <robertmhaas(at)gmail(dot)com>
Security: CVE-2026-6470
Backpatch-through: 14

Branch
------
REL_15_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/6dbedd48b7c5024ef847572f073b94c3eed88042
Author: Nathan Bossart <nathan(at)postgresql(dot)org>

Modified Files
--------------
src/backend/catalog/dependency.c | 81 ++++++++++++++++++++++++++++++++
src/backend/catalog/heap.c | 22 +++++++++
src/backend/catalog/index.c | 3 ++
src/backend/catalog/pg_attrdef.c | 3 ++
src/backend/catalog/pg_constraint.c | 3 ++
src/backend/catalog/pg_proc.c | 6 +++
src/backend/catalog/pg_publication.c | 3 ++
src/backend/catalog/pg_type.c | 6 +++
src/backend/commands/indexcmds.c | 16 +++++++
src/backend/commands/policy.c | 8 ++++
src/backend/commands/statscmds.c | 5 ++
src/backend/commands/tablecmds.c | 19 +++++++-
src/backend/commands/trigger.c | 5 ++
src/backend/commands/typecmds.c | 33 +++++++++++--
src/backend/parser/parse_utilcmd.c | 10 ++++
src/backend/rewrite/rewriteDefine.c | 2 +
src/backend/tcop/utility.c | 3 +-
src/include/catalog/dependency.h | 4 ++
src/include/commands/typecmds.h | 3 +-
src/test/regress/expected/privileges.out | 46 ++++++++++++++++++
src/test/regress/sql/privileges.sql | 43 +++++++++++++++++
21 files changed, 315 insertions(+), 9 deletions(-)