From 79243de13f4d251309d7831744e98d6b965ed4d6 Mon Sep 17 00:00:00 2001 From: Amit Kapila Date: Tue, 17 Oct 2023 08:30:05 +0530 Subject: [PATCH] Restart the apply worker if the privileges have been revoked. Restart the apply worker if the subscription owner's superuser privileges have been revoked. This is required so that the subscription connection string gets revalidated and use the password option to connect to the publisher for non-superusers, if required. Author: Vignesh C Reviewed-by: Amit Kapila Discussion: http://postgr.es/m/CALDaNm2Dxmhq08nr4P6G+24QvdBo_GAVyZ_Q1TcGYK+8NHs9xw@mail.gmail.com --- src/backend/catalog/pg_subscription.c | 3 ++ src/backend/commands/subscriptioncmds.c | 4 +-- src/backend/replication/logical/tablesync.c | 6 ++-- src/backend/replication/logical/worker.c | 33 +++++++++++++++++---- src/include/catalog/pg_subscription.h | 1 + src/test/subscription/t/027_nosuperuser.pl | 24 +++++++++++++++ 6 files changed, 60 insertions(+), 11 deletions(-) diff --git a/src/backend/catalog/pg_subscription.c b/src/backend/catalog/pg_subscription.c index d07f88ce28..d6a978f136 100644 --- a/src/backend/catalog/pg_subscription.c +++ b/src/backend/catalog/pg_subscription.c @@ -108,6 +108,9 @@ GetSubscription(Oid subid, bool missing_ok) Anum_pg_subscription_suborigin); sub->origin = TextDatumGetCString(datum); + /* Is the subscription owner a superuser? */ + sub->ownersuperuser = superuser_arg(sub->owner); + ReleaseSysCache(tup); return sub; diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c index 6fe111e98d..edc82c11be 100644 --- a/src/backend/commands/subscriptioncmds.c +++ b/src/backend/commands/subscriptioncmds.c @@ -869,7 +869,7 @@ AlterSubscription_refresh(Subscription *sub, bool copy_data, load_file("libpqwalreceiver", false); /* Try to connect to the publisher. */ - must_use_password = !superuser_arg(sub->owner) && sub->passwordrequired; + must_use_password = sub->passwordrequired && !sub->ownersuperuser; wrconn = walrcv_connect(sub->conninfo, true, must_use_password, sub->name, &err); if (!wrconn) @@ -1249,7 +1249,7 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt, load_file("libpqwalreceiver", false); /* Check the connection info string. */ walrcv_check_conninfo(stmt->conninfo, - sub->passwordrequired && !superuser_arg(sub->owner)); + sub->passwordrequired && !sub->ownersuperuser); values[Anum_pg_subscription_subconninfo - 1] = CStringGetTextDatum(stmt->conninfo); diff --git a/src/backend/replication/logical/tablesync.c b/src/backend/replication/logical/tablesync.c index e2cee92cf2..37a0abe2f4 100644 --- a/src/backend/replication/logical/tablesync.c +++ b/src/backend/replication/logical/tablesync.c @@ -1275,13 +1275,11 @@ LogicalRepSyncTableStart(XLogRecPtr *origin_startpos) relstate = GetSubscriptionRelState(MyLogicalRepWorker->subid, MyLogicalRepWorker->relid, &relstate_lsn); + CommitTransactionCommand(); /* Is the use of a password mandatory? */ must_use_password = MySubscription->passwordrequired && - !superuser_arg(MySubscription->owner); - - /* Note that the superuser_arg call can access the DB */ - CommitTransactionCommand(); + !MySubscription->ownersuperuser; SpinLockAcquire(&MyLogicalRepWorker->relmutex); MyLogicalRepWorker->relstate = relstate; diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c index 597947410f..54c14495be 100644 --- a/src/backend/replication/logical/worker.c +++ b/src/backend/replication/logical/worker.c @@ -3966,6 +3966,24 @@ maybe_reread_subscription(void) apply_worker_exit(); } + /* + * Exit if the subscription owner's superuser privileges have been + * revoked. + */ + if (!newsub->ownersuperuser && MySubscription->ownersuperuser) + { + if (am_parallel_apply_worker()) + ereport(LOG, + errmsg("logical replication parallel apply worker for subscription \"%s\" will stop because the subscription owner's superuser privileges have been revoked", + MySubscription->name)); + else + ereport(LOG, + errmsg("logical replication worker for subscription \"%s\" will restart because the subscription owner's superuser privileges have been revoked", + MySubscription->name)); + + apply_worker_exit(); + } + /* Check for other changes that should never happen too. */ if (newsub->dbid != MySubscription->dbid) { @@ -4492,13 +4510,11 @@ run_apply_worker() replorigin_session_setup(originid, 0); replorigin_session_origin = originid; origin_startpos = replorigin_session_get_progress(false); + CommitTransactionCommand(); /* Is the use of a password mandatory? */ must_use_password = MySubscription->passwordrequired && - !superuser_arg(MySubscription->owner); - - /* Note that the superuser_arg call can access the DB */ - CommitTransactionCommand(); + !MySubscription->ownersuperuser; LogRepWorkerWalRcvConn = walrcv_connect(MySubscription->conninfo, true, must_use_password, @@ -4621,11 +4637,18 @@ InitializeLogRepWorker(void) SetConfigOption("synchronous_commit", MySubscription->synccommit, PGC_BACKEND, PGC_S_OVERRIDE); - /* Keep us informed about subscription changes. */ + /* + * Keep us informed about subscription or role changes. Note that the + * role's superuser privilege can be revoked. + */ CacheRegisterSyscacheCallback(SUBSCRIPTIONOID, subscription_change_cb, (Datum) 0); + CacheRegisterSyscacheCallback(AUTHOID, + subscription_change_cb, + (Datum) 0); + if (am_tablesync_worker()) ereport(LOG, (errmsg("logical replication table synchronization worker for subscription \"%s\", table \"%s\" has started", diff --git a/src/include/catalog/pg_subscription.h b/src/include/catalog/pg_subscription.h index be36c4a820..e0b91eacd2 100644 --- a/src/include/catalog/pg_subscription.h +++ b/src/include/catalog/pg_subscription.h @@ -127,6 +127,7 @@ typedef struct Subscription * skipped */ char *name; /* Name of the subscription */ Oid owner; /* Oid of the subscription owner */ + bool ownersuperuser; /* Is the subscription owner a superuser? */ bool enabled; /* Indicates if the subscription is enabled */ bool binary; /* Indicates if the subscription wants data in * binary format */ diff --git a/src/test/subscription/t/027_nosuperuser.pl b/src/test/subscription/t/027_nosuperuser.pl index d7a7e3ef5b..642baa5d7c 100644 --- a/src/test/subscription/t/027_nosuperuser.pl +++ b/src/test/subscription/t/027_nosuperuser.pl @@ -104,6 +104,7 @@ for my $node ($node_publisher, $node_subscriber) CREATE ROLE regress_admin SUPERUSER LOGIN; CREATE ROLE regress_alice NOSUPERUSER LOGIN; GRANT CREATE ON DATABASE postgres TO regress_alice; + GRANT PG_CREATE_SUBSCRIPTION TO regress_alice; SET SESSION AUTHORIZATION regress_alice; CREATE SCHEMA alice; GRANT USAGE ON SCHEMA alice TO regress_admin; @@ -303,4 +304,27 @@ GRANT SELECT ON alice.unpartitioned TO regress_alice; expect_replication("alice.unpartitioned", 3, 17, 21, "restoring SELECT permission permits replication to continue"); +# The apply worker should get restarted after the superuser privileges are +# revoked for subscription owner alice. +grant_superuser("regress_alice"); +$node_subscriber->safe_psql( + 'postgres', qq( +SET SESSION AUTHORIZATION regress_alice; +CREATE SUBSCRIPTION regression_sub CONNECTION '$publisher_connstr' PUBLICATION alice; +)); + +# Wait for initial sync to finish +$node_subscriber->wait_for_subscription_sync($node_publisher, + 'regression_sub'); + +# Check the subscriber log from now on. +$offset = -s $node_subscriber->logfile; + +revoke_superuser("regress_alice"); + +# After the user becomes non-superuser the apply worker should be restarted. +$node_subscriber->wait_for_log( + qr/LOG: ( [A-Z0-9]+:)? logical replication worker for subscription \"regression_sub\" will restart because the subscription owner's superuser privileges have been revoked/, + $offset); + done_testing();