not allow backsteps in local volume plugin

pkg/api/validation/validation.go

@@ -1133,7 +1133,10 @@ func validateLocalVolumeSource(ls *api.LocalVolumeSource, fldPath *field.Path) f
 	allErrs := field.ErrorList{}
 	if ls.Path == "" {
 		allErrs = append(allErrs, field.Required(fldPath.Child("path"), ""))
+		return allErrs
 	}
+
+	allErrs = append(allErrs, validatePathNoBacksteps(ls.Path, fldPath.Child("path"))...)
 	return allErrs
 }
 

pkg/api/validation/validation_test.go

@@ -281,6 +281,21 @@ func TestValidatePersistentVolumes(t *testing.T) {
 				StorageClassName: "backstep-hostpath",
 			}),
 		},
+		"bad-local-volume-backsteps": {
+			isExpectedFailure: true,
+			volume: testVolume("foo", "", api.PersistentVolumeSpec{
+				Capacity: api.ResourceList{
+					api.ResourceName(api.ResourceStorage): resource.MustParse("10G"),
+				},
+				AccessModes: []api.PersistentVolumeAccessMode{api.ReadWriteOnce},
+				PersistentVolumeSource: api.PersistentVolumeSource{
+					Local: &api.LocalVolumeSource{
+						Path: "/foo/..",
+					},
+				},
+				StorageClassName: "backstep-local",
+			}),
+		},
 	}
 
 	for name, scenario := range scenarios {