From HEAD:

+       Fixed slapd-bdb/hdb referral issue (ITS#4548)

CHANGES

@@ -19,8 +19,9 @@ OpenLDAP 2.3.22 Release
 	Fixed slapd slap_send_ldap_result bug (ITS#4499)
 	Fixed slapd thread pool init issue (ITS#4513)
 	Added slapd syncrepl mandatory searchbase check
-	Fixed slapd-bdb pre/post-read freeing (ITS#4532)
-	Fixed slapd-bdb pre/post-read unavailable issue (ITS#4538)
+	Fixed slapd-bdb/hdb pre/post-read freeing (ITS#4532)
+	Fixed slapd-bdb/hdb pre/post-read unavailable issue (ITS#4538)
+	Fixed slapd-bdb/hdb referral issue (ITS#4548)
 	Fixed slapd-hdb IDL sort issue (ITS#4531)
 	Fixed slapd-ldap proxyAuthz of bound identity/override (ITS#4497)
 	Fixed slapd-ldap/meta protocol version propagation (ITS#4488)

servers/slapd/back-bdb/referral.c

@@ -91,8 +91,11 @@ dn2entry_retry:
 				(long) op->o_tag, op->o_req_dn.bv_val, e->e_name.bv_val );
 
 			if( is_entry_referral( e ) ) {
+				BerVarray ref = get_entry_referrals( op, e );
 				rc = LDAP_OTHER;
-				rs->sr_ref = get_entry_referrals( op, e );
+				rs->sr_ref = referral_rewrite( ref, NULL,
+					&op->o_req_dn, LDAP_SCOPE_DEFAULT );
+				ber_bvarray_free( ref );
 				if ( rs->sr_ref ) {
 					rs->sr_matched = ber_strdup_x(
 					e->e_name.bv_val, op->o_tmpmemctx );