Index: sys/xen/xen_intr.c
===================================================================
--- sys/xen/xen_intr.c
+++ sys/xen/xen_intr.c
@@ -396,13 +396,18 @@
 
 	*isrcp = NULL;
 	if (port_handlep == NULL) {
+		xen_intr_handle_t discard;
 		printf("%s: %s: Bad event handle\n", intr_owner, __func__);
-		return (EINVAL);
+		port_handlep = &discard;
+		error = EINVAL;
+		goto failearly;
 	}
 
 	isrc = xen_intr_alloc_isrc(params);
-	if (isrc == NULL)
-		return (ENOSPC);
+	if (isrc == NULL) {
+		error = ENOSPC;
+		goto failearly;
+	}
 	refcount_init(&isrc->xi_refcount, 1);
 	cpu = isrc->xi_cpu;
 	mtx_lock(&xen_intr_isrc_lock);
@@ -428,10 +433,8 @@
 	}
 
 	error = xen_arch_intr_event_bind(isrc, cpu);
-	if (error != 0) { /* *very* unlikely */
-		xen_intr_release_isrc(isrc);
-		return (error);
-	}
+	if (error != 0) /* *very* unlikely */
+		goto failrelease;
 
 	if (isrc->xi_cpu != cpu) {
 		/*
@@ -456,12 +459,17 @@
 
 	error = xen_intr_add_handler(intr_owner, filter, handler, arg, flags,
 	    *port_handlep);
-	if (error != 0) {
-		xen_intr_release_isrc(isrc);
-		return (error);
-	}
+	if (error != 0)
+		goto failrelease;
 	*isrcp = isrc;
 	return (0);
+
+failrelease:
+	xen_intr_release_isrc(isrc);
+
+failearly:
+	*port_handlep = NULL;
+	return (error);
 }
 
 /**