--- bt.c
+++ bt.c
@@ -786,6 +786,17 @@
 	/*
 	 * Setup interrupt.
 	 */
 	error = bus_setup_intr(dev, bt->irq,
 	    INTR_MPSAFE, bt_intr, bt, &bt->ih, NULL);
 	if (error) {
 		device_printf(dev, "bus_setup_intr() failed: %d\n", error);
+		/*
+		 * Tear down the CAM state registered above.  The PCI
+		 * glue releases our port/IRQ resources and DMA memory
+		 * on attach failure; the XPT must not keep a bus whose
+		 * sim action closure points at the freed softc.
+		 */
+		lockmgr(&bt->lock, LK_EXCLUSIVE);
+		xpt_free_path(bt->path);
+		bt->path = NULL;
+		xpt_bus_deregister(cam_sim_path(bt->sim));
+		cam_sim_free(bt->sim);
+		bt->sim = NULL;
+		lockmgr(&bt->lock, LK_RELEASE);
 		return (error);
 	}
 
 	return (0);