On 27/08/26 16:19, Nathan Bossart wrote:
The patch looks reasonable to me.
On Thu, Aug 27, 2026 at 03:55:11PM -0300, Matheus Alcantara wrote:
Added this new test case on attached.
I'm not sure the new tests are necessary. It seems unlikely that we'll
accidentally remove the flags down the road.
Yeah, I also think that is unlikely that we'll remove, I just put the
test to be more conservative. I think that is good to have such tests
to ensure that these bugs are not re-introduced but given that this
seems a minor/oversight I'm not totally against not adding them.
Attached is v3 without the tests.
--
Matheus Alcantara
EDB: https://www.enterprisedb.com
From 7f5ec60686edbc3c0555bfa5c743719405321002 Mon Sep 17 00:00:00 2001
From: Matheus Alcantara <[email protected]>
Date: Thu, 27 Aug 2026 15:07:39 -0300
Subject: [PATCH v3] Let the REPACK decoding worker bypass connection privilege
checks
REPACK (CONCURRENTLY) launches a background worker to decode the changes
made while the table is being rewritten. Since cluster_rel() switches
the current user to the owner of the table being repacked, that is the
role the worker connects as, and the worker asked for a bypass of the
LOGIN check only. The CONNECT privilege on the database was therefore
still checked against the table owner, who has no reason to have it, so
the command could fail with
ERROR: permission denied for database "d"
DETAIL: User does not have CONNECT privilege.
CONTEXT: REPACK decoding worker
Pass BGWORKER_BYPASS_ALLOWCONN as well, as parallel.c already does for
parallel workers: the backend that launched the worker is connected to
the database already, and the worker only decodes changes on its behalf.
Author: Matheus Alcantara <[email protected]>
Reported-by: Nathan Bossart <[email protected]>
Discussion: https://www.postgresql.org/message-id/apBbzFd_EYAfHV45@nathan
---
src/backend/commands/repack_worker.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/src/backend/commands/repack_worker.c
b/src/backend/commands/repack_worker.c
index af7e2a94764..a49b681059f 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -101,8 +101,15 @@ RepackWorkerMain(Datum main_arg)
pq_set_parallel_leader(shared->backend_pid,
shared->backend_proc_number);
- /* Connect to the database. LOGIN is not required. */
+ /*
+ * Connect to the database. Like parallel workers do, we skip the
+ * connection authorization checks. The backend that launched us is
+ * already connected to this database, and the role we run as is the
owner
+ * of the table being repacked, which needs neither the LOGIN attribute
+ * nor the CONNECT privilege for our purposes.
+ */
BackgroundWorkerInitializeConnectionByOid(shared->dbid, shared->roleid,
+
BGWORKER_BYPASS_ALLOWCONN |
BGWORKER_BYPASS_ROLELOGINCHECK);
/*
--
2.50.1 (Apple Git-155)
