Reserve the "pg_" namespace for roles

This will prevent users from creating roles which begin with "pg_" and
will check for those roles before allowing an upgrade using pg_upgrade.

This will allow for default roles to be provided at initdb time.

Reviews by José Luis Tallón and Robert Haas

doc/src/sgml/ref/psql-ref.sgml

@@ -1365,13 +1365,15 @@ testdb=>
 
 
       <varlistentry>
-        <term><literal>\dg[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
+        <term><literal>\dg[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
         <listitem>
         <para>
         Lists database roles.
         (Since the concepts of <quote>users</> and <quote>groups</> have been
         unified into <quote>roles</>, this command is now equivalent to
         <literal>\du</literal>.)
+        By default, only user-created roles are shown; supply the
+        <literal>S</literal> modifier to include system roles.
         If <replaceable class="parameter">pattern</replaceable> is specified,
         only those roles whose names match the pattern are listed.
         If the form <literal>\dg+</literal> is used, additional information
@@ -1525,13 +1527,15 @@ testdb=&gt;
       </varlistentry>
 
       <varlistentry>
-        <term><literal>\du[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
+        <term><literal>\du[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
         <listitem>
         <para>
         Lists database roles.
         (Since the concepts of <quote>users</> and <quote>groups</> have been
         unified into <quote>roles</>, this command is now equivalent to
         <literal>\dg</literal>.)
+        By default, only user-created roles are shown; supply the
+        <literal>S</literal> modifier to include system roles.
         If <replaceable class="parameter">pattern</replaceable> is specified,
         only those roles whose names match the pattern are listed.
         If the form <literal>\du+</literal> is used, additional information

src/backend/catalog/aclchk.c

@@ -423,6 +423,9 @@ ExecuteGrantStmt(GrantStmt *stmt)
 				grantee_uid = ACL_ID_PUBLIC;
 				break;
 			default:
+				if (!IsBootstrapProcessingMode())
+					check_rolespec_name((Node *) grantee,
+			"Cannot GRANT or REVOKE privileges to or from a reserved role.");
 				grantee_uid = get_rolespec_oid((Node *) grantee, false);
 				break;
 		}
@@ -918,6 +921,8 @@ ExecAlterDefaultPrivilegesStmt(AlterDefaultPrivilegesStmt *stmt)
 				grantee_uid = ACL_ID_PUBLIC;
 				break;
 			default:
+				check_rolespec_name((Node *) grantee,
+	"Cannot GRANT or REVOKE default privileges to or from a reserved role.");
 				grantee_uid = get_rolespec_oid((Node *) grantee, false);
 				break;
 		}
@@ -1008,6 +1013,8 @@ ExecAlterDefaultPrivilegesStmt(AlterDefaultPrivilegesStmt *stmt)
 		{
 			RoleSpec   *rolespec = lfirst(rolecell);
 
+			check_rolespec_name((Node *) rolespec,
+						"Cannot alter default privileges for reserved role.");
 			iacls.roleid = get_rolespec_oid((Node *) rolespec, false);
 
 			/*

src/backend/catalog/catalog.c

@@ -184,8 +184,9 @@ IsToastNamespace(Oid namespaceId)
  *		True iff name starts with the pg_ prefix.
  *
  *		For some classes of objects, the prefix pg_ is reserved for
- *		system objects only.  As of 8.0, this is only true for
- *		schema and tablespace names.
+ *		system objects only.  As of 8.0, this was only true for
+ *		schema and tablespace names.  With 9.6, this is also true
+ *		for roles.
  */
 bool
 IsReservedName(const char *name)

src/backend/commands/alter.c

@@ -747,6 +747,9 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
 {
 	Oid			newowner = get_rolespec_oid(stmt->newowner, false);
 
+	check_rolespec_name(stmt->newowner,
+						"Cannot make reserved roles owners of objects.");
+
 	switch (stmt->objectType)
 	{
 		case OBJECT_DATABASE:

src/backend/commands/foreigncmds.c

@@ -1148,6 +1148,10 @@ CreateUserMapping(CreateUserMappingStmt *stmt)
 	else
 		useId = get_rolespec_oid(stmt->user, false);
 
+	/* Additional check to protect reserved role names */
+	check_rolespec_name(stmt->user,
+						"Cannot specify reserved role as mapping user.");
+
 	/* Check that the server exists. */
 	srv = GetForeignServerByName(stmt->servername, false);
 
@@ -1248,6 +1252,10 @@ AlterUserMapping(AlterUserMappingStmt *stmt)
 	else
 		useId = get_rolespec_oid(stmt->user, false);
 
+	/* Additional check to protect reserved role names */
+	check_rolespec_name(stmt->user,
+						"Cannot alter reserved role mapping user.");
+
 	srv = GetForeignServerByName(stmt->servername, false);
 
 	umId = GetSysCacheOid2(USERMAPPINGUSERSERVER,
@@ -1337,6 +1345,11 @@ RemoveUserMapping(DropUserMappingStmt *stmt)
 	else
 	{
 		useId = get_rolespec_oid(stmt->user, stmt->missing_ok);
+
+		/* Additional check to protect reserved role names */
+		check_rolespec_name(stmt->user,
+							"Cannot remove reserved role mapping user.");
+
 		if (!OidIsValid(useId))
 		{
 			/*

src/backend/commands/policy.c

@@ -176,8 +176,13 @@ policy_role_list_to_array(List *roles, int *num_roles)
 			return role_oids;
 		}
 		else
+		{
+			/* Additional check to protect reserved role names */
+			check_rolespec_name((Node *) spec,
+							"Cannot specify reserved role as policy target");
 			role_oids[i++] =
 				ObjectIdGetDatum(get_rolespec_oid((Node *) spec, false));
+		}
 	}
 
 	return role_oids;

src/backend/commands/schemacmds.c

@@ -65,6 +65,10 @@ CreateSchemaCommand(CreateSchemaStmt *stmt, const char *queryString)
 	else
 		owner_uid = saved_uid;
 
+	/* Additional check to protect reserved role names */
+	check_rolespec_name(stmt->authrole,
+						"Cannot specify reserved role as owner.");
+
 	/* fill schema name with the user name if not specified */
 	if (!schemaName)
 	{

src/backend/commands/tablecmds.c

@@ -3566,6 +3566,8 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
 												(List *) cmd->def, lockmode);
 			break;
 		case AT_ChangeOwner:	/* ALTER OWNER */
+			check_rolespec_name(cmd->newowner,
+								"Cannot specify reserved role as owner.");
 			ATExecChangeOwner(RelationGetRelid(rel),
 							  get_rolespec_oid(cmd->newowner, false),
 							  false, lockmode);

src/backend/commands/tablespace.c

@@ -256,6 +256,10 @@ CreateTableSpace(CreateTableSpaceStmt *stmt)
 	else
 		ownerId = GetUserId();
 
+	/* Additional check to protect reserved role names */
+	check_rolespec_name(stmt->owner,
+						"Cannot specify reserved role as owner.");
+
 	/* Unix-ify the offered path, and strip any trailing slashes */
 	location = pstrdup(stmt->location);
 	canonicalize_path(location);

src/backend/commands/user.c

@@ -17,6 +17,7 @@
 #include "access/htup_details.h"
 #include "access/xact.h"
 #include "catalog/binary_upgrade.h"
+#include "catalog/catalog.h"
 #include "catalog/dependency.h"
 #include "catalog/indexing.h"
 #include "catalog/objectaccess.h"
@@ -311,6 +312,17 @@ CreateRole(CreateRoleStmt *stmt)
 					 errmsg("permission denied to create role")));
 	}
 
+	/*
+	 * Check that the user is not trying to create a role in the reserved
+	 * "pg_" namespace.
+	 */
+	if (IsReservedName(stmt->role))
+		ereport(ERROR,
+				(errcode(ERRCODE_RESERVED_NAME),
+				 errmsg("role name \"%s\" is reserved",
+					 stmt->role),
+				 errdetail("Role names starting with \"pg_\" are reserved.")));
+
 	/*
 	 * Check the pg_authid relation to be certain the role doesn't already
 	 * exist.
@@ -507,6 +519,9 @@ AlterRole(AlterRoleStmt *stmt)
 	DefElem    *dbypassRLS = NULL;
 	Oid			roleid;
 
+	check_rolespec_name(stmt->role,
+						"Cannot alter reserved roles.");
+
 	/* Extract options from the statement node tree */
 	foreach(option, stmt->options)
 	{
@@ -857,6 +872,9 @@ AlterRoleSet(AlterRoleSetStmt *stmt)
 
 	if (stmt->role)
 	{
+		check_rolespec_name(stmt->role,
+							"Cannot alter reserved roles.");
+
 		roletuple = get_rolespec_tuple(stmt->role);
 		roleid = HeapTupleGetOid(roletuple);
 
@@ -1117,6 +1135,7 @@ RenameRole(const char *oldname, const char *newname)
 	int			i;
 	Oid			roleid;
 	ObjectAddress address;
+	Form_pg_authid authform;
 
 	rel = heap_open(AuthIdRelationId, RowExclusiveLock);
 	dsc = RelationGetDescr(rel);
@@ -1136,6 +1155,7 @@ RenameRole(const char *oldname, const char *newname)
 	 */
 
 	roleid = HeapTupleGetOid(oldtuple);
+	authform = (Form_pg_authid) GETSTRUCT(oldtuple);
 
 	if (roleid == GetSessionUserId())
 		ereport(ERROR,
@@ -1146,6 +1166,24 @@ RenameRole(const char *oldname, const char *newname)
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("current user cannot be renamed")));
 
+	/*
+	 * Check that the user is not trying to rename a system role and
+	 * not trying to rename a role into the reserved "pg_" namespace.
+	 */
+	if (IsReservedName(NameStr(authform->rolname)))
+		ereport(ERROR,
+				(errcode(ERRCODE_RESERVED_NAME),
+				 errmsg("role name \"%s\" is reserved",
+					 NameStr(authform->rolname)),
+				 errdetail("Role names starting with \"pg_\" are reserved.")));
+
+	if (IsReservedName(newname))
+		ereport(ERROR,
+				(errcode(ERRCODE_RESERVED_NAME),
+				 errmsg("role name \"%s\" is reserved",
+					 newname),
+				 errdetail("Role names starting with \"pg_\" are reserved.")));
+
 	/* make sure the new name doesn't exist */
 	if (SearchSysCacheExists1(AUTHNAME, CStringGetDatum(newname)))
 		ereport(ERROR,
@@ -1224,10 +1262,18 @@ GrantRole(GrantRoleStmt *stmt)
 	ListCell   *item;
 
 	if (stmt->grantor)
+	{
+		check_rolespec_name(stmt->grantor,
+							"Cannot specify reserved role as grantor.");
 		grantor = get_rolespec_oid(stmt->grantor, false);
+	}
 	else
 		grantor = GetUserId();
 
+	foreach(item, stmt->grantee_roles)
+		check_rolespec_name(lfirst(item),
+							"Cannot GRANT roles to a reserved role.");
+
 	grantee_ids = roleSpecsToIds(stmt->grantee_roles);
 
 	/* AccessShareLock is enough since we aren't modifying pg_authid */
@@ -1318,6 +1364,9 @@ ReassignOwnedObjects(ReassignOwnedStmt *stmt)
 					 errmsg("permission denied to reassign objects")));
 	}
 
+	check_rolespec_name(stmt->newrole,
+						"Cannot specify reserved role as owner.");
+
 	/* Must have privileges on the receiving side too */
 	newrole = get_rolespec_oid(stmt->newrole, false);
 

src/backend/commands/variable.c

@@ -854,6 +854,9 @@ check_role(char **newval, void **extra, GucSource source)
 		roleid = InvalidOid;
 		is_superuser = false;
 	}
+	/* Do not allow setting role to a reserved role. */
+	else if (strncmp(*newval, "pg_", 3) == 0)
+		return false;
 	else
 	{
 		if (!IsTransactionState())

src/backend/utils/adt/acl.c

@@ -17,6 +17,7 @@
 #include <ctype.h>
 
 #include "access/htup_details.h"
+#include "catalog/catalog.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_authid.h"
 #include "catalog/pg_auth_members.h"
@@ -5247,3 +5248,41 @@ get_rolespec_name(const Node *node)
 
 	return rolename;
 }
+
+/*
+ * Given a RoleSpec, throw an error if the name is reserved, using detail_msg,
+ * if provided.
+ *
+ * If node is NULL, no error is thrown.  If detail_msg is NULL then no detail
+ * message is provided.
+ */
+void
+check_rolespec_name(const Node *node, const char *detail_msg)
+{
+	RoleSpec   *role;
+
+	if (!node)
+		return;
+
+	role = (RoleSpec *) node;
+
+	Assert(IsA(node, RoleSpec));
+
+	if (role->roletype != ROLESPEC_CSTRING)
+		return;
+
+	if (IsReservedName(role->rolename))
+	{
+		if (detail_msg)
+			ereport(ERROR,
+					(errcode(ERRCODE_RESERVED_NAME),
+					 errmsg("role \"%s\" is reserved",
+						 role->rolename),
+					 errdetail("%s", detail_msg)));
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_RESERVED_NAME),
+					 errmsg("role \"%s\" is reserved",
+						 role->rolename)));
+	}
+}

src/bin/pg_dump/pg_dumpall.c

@@ -665,7 +665,7 @@ dumpRoles(PGconn *conn)
 	int			i;
 
 	/* note: rolconfig is dumped later */
-	if (server_version >= 90500)
+	if (server_version >= 90600)
 		printfPQExpBuffer(buf,
 						  "SELECT oid, rolname, rolsuper, rolinherit, "
 						  "rolcreaterole, rolcreatedb, "
@@ -674,6 +674,7 @@ dumpRoles(PGconn *conn)
 			 "pg_catalog.shobj_description(oid, 'pg_authid') as rolcomment, "
 						  "rolname = current_user AS is_current_user "
 						  "FROM pg_authid "
+						  "WHERE rolname !~ '^pg_' "
 						  "ORDER BY 2");
 	else if (server_version >= 90100)
 		printfPQExpBuffer(buf,
@@ -771,6 +772,13 @@ dumpRoles(PGconn *conn)
 		auth_oid = atooid(PQgetvalue(res, i, i_oid));
 		rolename = PQgetvalue(res, i, i_rolname);
 
+		if (strncmp(rolename,"pg_",3) == 0)
+		{
+			fprintf(stderr, _("%s: role name starting with 'pg_' skipped (%s)\n"),
+					progname, rolename);
+			continue;
+		}
+
 		resetPQExpBuffer(buf);
 
 		if (binary_upgrade)
@@ -896,6 +904,7 @@ dumpRoleMembership(PGconn *conn)
 					   "LEFT JOIN pg_authid ur on ur.oid = a.roleid "
 					   "LEFT JOIN pg_authid um on um.oid = a.member "
 					   "LEFT JOIN pg_authid ug on ug.oid = a.grantor "
+					   "WHERE NOT (ur.rolname ~ '^pg_' AND um.rolname ~ '^pg_')"
 					   "ORDER BY 1,2,3");
 
 	if (PQntuples(res) > 0)

src/bin/pg_upgrade/check.c

@@ -24,6 +24,7 @@ static void check_for_prepared_transactions(ClusterInfo *cluster);
 static void check_for_isn_and_int8_passing_mismatch(ClusterInfo *cluster);
 static void check_for_reg_data_type_usage(ClusterInfo *cluster);
 static void check_for_jsonb_9_4_usage(ClusterInfo *cluster);
+static void check_for_pg_role_prefix(ClusterInfo *cluster);
 static void get_bin_version(ClusterInfo *cluster);
 static char *get_canonical_locale_name(int category, const char *locale);
 
@@ -96,6 +97,11 @@ check_and_dump_old_cluster(bool live_check)
 	check_for_prepared_transactions(&old_cluster);
 	check_for_reg_data_type_usage(&old_cluster);
 	check_for_isn_and_int8_passing_mismatch(&old_cluster);
+
+	/* 9.5 and below should not have roles starting with pg_ */
+	if (GET_MAJOR_VERSION(old_cluster.major_version) <= 905)
+		check_for_pg_role_prefix(&old_cluster);
+
 	if (GET_MAJOR_VERSION(old_cluster.major_version) == 904 &&
 		old_cluster.controldata.cat_ver < JSONB_FORMAT_CHANGE_CAT_VER)
 		check_for_jsonb_9_4_usage(&old_cluster);
@@ -629,7 +635,8 @@ check_is_install_user(ClusterInfo *cluster)
 	res = executeQueryOrDie(conn,
 							"SELECT rolsuper, oid "
 							"FROM pg_catalog.pg_roles "
-							"WHERE rolname = current_user");
+							"WHERE rolname = current_user "
+							"AND rolname !~ '^pg_'");
 
 	/*
 	 * We only allow the install user in the new cluster (see comment below)
@@ -645,7 +652,8 @@ check_is_install_user(ClusterInfo *cluster)
 
 	res = executeQueryOrDie(conn,
 							"SELECT COUNT(*) "
-							"FROM pg_catalog.pg_roles ");
+							"FROM pg_catalog.pg_roles "
+							"WHERE rolname !~ '^pg_'");
 
 	if (PQntuples(res) != 1)
 		pg_fatal("could not determine the number of users\n");
@@ -1033,6 +1041,34 @@ check_for_jsonb_9_4_usage(ClusterInfo *cluster)
 		check_ok();
 }
 
+/*
+ * check_for_pg_role_prefix()
+ *
+ *	Versions older than 9.6 should not have any pg_* roles
+ */
+static void
+check_for_pg_role_prefix(ClusterInfo *cluster)
+{
+	PGresult   *res;
+	PGconn	   *conn = connectToServer(cluster, "template1");
+
+	prep_status("Checking for roles starting with 'pg_'");
+
+	res = executeQueryOrDie(conn,
+							"SELECT * "
+							"FROM pg_catalog.pg_roles "
+							"WHERE rolname ~ '^pg_'");
+
+	if (PQntuples(res) != 0)
+		pg_fatal("The %s cluster contains roles starting with 'pg_'\n",
+				 CLUSTER_NAME(cluster));
+
+	PQclear(res);
+
+	PQfinish(conn);
+
+	check_ok();
+}
 
 static void
 get_bin_version(ClusterInfo *cluster)

src/bin/psql/command.c

@@ -429,7 +429,7 @@ exec_command(const char *cmd,
 				break;
 			case 'g':
 				/* no longer distinct from \du */
-				success = describeRoles(pattern, show_verbose);
+				success = describeRoles(pattern, show_verbose, show_system);
 				break;
 			case 'l':
 				success = do_lo_list();
@@ -474,7 +474,7 @@ exec_command(const char *cmd,
 					success = PSQL_CMD_UNKNOWN;
 				break;
 			case 'u':
-				success = describeRoles(pattern, show_verbose);
+				success = describeRoles(pattern, show_verbose, show_system);
 				break;
 			case 'F':			/* text search subsystem */
 				switch (cmd[2])

src/bin/psql/describe.c

@@ -2646,7 +2646,7 @@ add_tablespace_footer(printTableContent *const cont, char relkind,
  * Describes roles.  Any schema portion of the pattern is ignored.
  */
 bool
-describeRoles(const char *pattern, bool verbose)
+describeRoles(const char *pattern, bool verbose, bool showSystem)
 {
 	PQExpBufferData buf;
 	PGresult   *res;
@@ -2691,6 +2691,9 @@ describeRoles(const char *pattern, bool verbose)
 
 		appendPQExpBufferStr(&buf, "\nFROM pg_catalog.pg_roles r\n");
 
+		if (!showSystem && !pattern)
+			appendPQExpBufferStr(&buf, "WHERE r.rolname !~ '^pg_'\n");
+
 		processSQLNamePattern(pset.db, &buf, pattern, false, false,
 							  NULL, "r.rolname", NULL, NULL);
 	}

src/bin/psql/describe.h

@@ -25,7 +25,7 @@ extern bool describeTypes(const char *pattern, bool verbose, bool showSystem);
 extern bool describeOperators(const char *pattern, bool verbose, bool showSystem);
 
 /* \du, \dg */
-extern bool describeRoles(const char *pattern, bool verbose);
+extern bool describeRoles(const char *pattern, bool verbose, bool showSystem);
 
 /* \drds */
 extern bool listDbRoleSettings(const char *pattern1, const char *pattern2);

src/bin/psql/help.c

@@ -229,7 +229,7 @@ slashUsage(unsigned short int pager)
 	fprintf(output, _("  \\dFd[+] [PATTERN]      list text search dictionaries\n"));
 	fprintf(output, _("  \\dFp[+] [PATTERN]      list text search parsers\n"));
 	fprintf(output, _("  \\dFt[+] [PATTERN]      list text search templates\n"));
-	fprintf(output, _("  \\dg[+]  [PATTERN]      list roles\n"));
+	fprintf(output, _("  \\dg[S+] [PATTERN]      list roles\n"));
 	fprintf(output, _("  \\di[S+] [PATTERN]      list indexes\n"));
 	fprintf(output, _("  \\dl                    list large objects, same as \\lo_list\n"));
 	fprintf(output, _("  \\dL[S+] [PATTERN]      list procedural languages\n"));
@@ -242,7 +242,7 @@ slashUsage(unsigned short int pager)
 	fprintf(output, _("  \\ds[S+] [PATTERN]      list sequences\n"));
 	fprintf(output, _("  \\dt[S+] [PATTERN]      list tables\n"));
 	fprintf(output, _("  \\dT[S+] [PATTERN]      list data types\n"));
-	fprintf(output, _("  \\du[+]  [PATTERN]      list roles\n"));
+	fprintf(output, _("  \\du[S+] [PATTERN]      list roles\n"));
 	fprintf(output, _("  \\dv[S+] [PATTERN]      list views\n"));
 	fprintf(output, _("  \\dE[S+] [PATTERN]      list foreign tables\n"));
 	fprintf(output, _("  \\dx[+]  [PATTERN]      list extensions\n"));

src/include/utils/acl.h

@@ -231,6 +231,7 @@ extern void check_is_member_of_role(Oid member, Oid role);
 extern Oid	get_role_oid(const char *rolename, bool missing_ok);
 extern Oid	get_role_oid_or_public(const char *rolename);
 extern Oid	get_rolespec_oid(const Node *node, bool missing_ok);
+extern void	check_rolespec_name(const Node *node, const char *detail_msg);
 extern HeapTuple get_rolespec_tuple(const Node *node);
 extern char *get_rolespec_name(const Node *node);
 

src/test/regress/expected/rolenames.out

@@ -78,6 +78,18 @@ CREATE ROLE "none"; -- error
 ERROR:  role name "none" is reserved
 LINE 1: CREATE ROLE "none";
                     ^
+CREATE ROLE pg_abc; -- error
+ERROR:  role name "pg_abc" is reserved
+DETAIL:  Role names starting with "pg_" are reserved.
+CREATE ROLE "pg_abc"; -- error
+ERROR:  role name "pg_abc" is reserved
+DETAIL:  Role names starting with "pg_" are reserved.
+CREATE ROLE pg_abcdef; -- error
+ERROR:  role name "pg_abcdef" is reserved
+DETAIL:  Role names starting with "pg_" are reserved.
+CREATE ROLE "pg_abcdef"; -- error
+ERROR:  role name "pg_abcdef" is reserved
+DETAIL:  Role names starting with "pg_" are reserved.
 CREATE ROLE testrol0 SUPERUSER LOGIN;
 CREATE ROLE testrolx SUPERUSER LOGIN;
 CREATE ROLE testrol2 SUPERUSER;
@@ -804,6 +816,14 @@ LINE 1: DROP USER MAPPING IF EXISTS FOR CURRENT_ROLE SERVER sv9;
 DROP USER MAPPING IF EXISTS FOR nonexistent SERVER sv9;  -- error
 NOTICE:  role "nonexistent" does not exist, skipping
 -- GRANT/REVOKE
+GRANT testrol0 TO pg_abc; -- error
+ERROR:  role "pg_abc" is reserved
+DETAIL:  Cannot GRANT roles to a reserved role.
+GRANT pg_abc TO pg_abcdef; -- error
+ERROR:  role "pg_abcdef" is reserved
+DETAIL:  Cannot GRANT roles to a reserved role.
+SET ROLE pg_testrole; -- error
+ERROR:  invalid value for parameter "role": "pg_testrole"
 UPDATE pg_proc SET proacl = null WHERE proname LIKE 'testagg_';
 SELECT proname, proacl FROM pg_proc WHERE proname LIKE 'testagg_';
  proname  | proacl 

src/test/regress/sql/rolenames.sql

@@ -57,6 +57,11 @@ CREATE ROLE "public"; -- error
 CREATE ROLE none; -- error
 CREATE ROLE "none"; -- error
 
+CREATE ROLE pg_abc; -- error
+CREATE ROLE "pg_abc"; -- error
+CREATE ROLE pg_abcdef; -- error
+CREATE ROLE "pg_abcdef"; -- error
+
 CREATE ROLE testrol0 SUPERUSER LOGIN;
 CREATE ROLE testrolx SUPERUSER LOGIN;
 CREATE ROLE testrol2 SUPERUSER;
@@ -376,6 +381,11 @@ DROP USER MAPPING IF EXISTS FOR CURRENT_ROLE SERVER sv9; --error
 DROP USER MAPPING IF EXISTS FOR nonexistent SERVER sv9;  -- error
 
 -- GRANT/REVOKE
+GRANT testrol0 TO pg_abc; -- error
+GRANT pg_abc TO pg_abcdef; -- error
+
+SET ROLE pg_testrole; -- error
+
 UPDATE pg_proc SET proacl = null WHERE proname LIKE 'testagg_';
 SELECT proname, proacl FROM pg_proc WHERE proname LIKE 'testagg_';