Index: sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_file.c
===================================================================
--- sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_file.c	(wersja 208452)
+++ sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_file.c	(kopia robocza)
@@ -120,9 +120,14 @@
 {
 	vdev_t *vd = zio->io_vd;
 	vdev_file_t *vf = vd->vdev_tsd;
-	vnode_t *vp = vf->vf_vnode;
+	vnode_t *vp;
 	ssize_t resid;
 
+	if (vf == NULL || (vp = vf->vf_vnode) == NULL) {
+		zio->io_error = ENXIO;
+		return (ZIO_PIPELINE_CONTINUE);
+	}
+
 	if (zio->io_type == ZIO_TYPE_IOCTL) {
 		/* XXPOLICY */
 		if (!vdev_readable(vd)) {