Index: sys/boot/zfs/zfsimpl.c
===================================================================
--- sys/boot/zfs/zfsimpl.c	(revision 224560)
+++ sys/boot/zfs/zfsimpl.c	(working copy)
@@ -949,10 +949,10 @@ vdev_probe(vdev_phys_read_t *read, void *read_priv
 		if (up->ub_txg < spa->spa_txg)
 			continue;
 		if (up->ub_txg > spa->spa_uberblock.ub_txg) {
-			spa->spa_uberblock = *up;
+			memcpy(&spa->spa_uberblock, up, sizeof(*up));
 		} else if (up->ub_txg == spa->spa_uberblock.ub_txg) {
 			if (up->ub_timestamp > spa->spa_uberblock.ub_timestamp)
-				spa->spa_uberblock = *up;
+				memcpy(&spa->spa_uberblock, up, sizeof(*up));
 		}
 	}
 	zfs_free(upbuf, VDEV_UBERBLOCK_SIZE(vdev));
@@ -1703,6 +1703,6 @@ zfs_lookup(spa_t *spa, const char *upath, dnode_ph
 		}
 	}
 
-	*dnode = dn;
+	memcpy(dnode, &dn, sizeof(dn));
 	return (0);
 }