Merge pull request #47236 from dixudx/not_allow_backsteps_in_local_volume

Automatic merge from submit-queue (batch tested with PRs 34515, 47236, 46694, 47819, 47792)

not allow backsteps in local volume plugin

**Which issue this PR fixes** : fixes #47207

**Special notes for your reviewer**:
cc @msau42 @ddysher
Just follow @liggitt [commented](https://github.com/kubernetes/kubernetes/issues/47107#issuecomment-306831175).

**Release note**:
```release-note
NONE
```

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 {