@@ -3175,3 +3175,57 @@ func TestBuildExoticShellInterpolation(t *testing.T) {

 	logDone("build - exotic shell interpolation")

 }

+

+func TestBuildSymlinkBreakout(t *testing.T) {

+	name := "testbuildsymlinkbreakout"

+	tmpdir, err := ioutil.TempDir("", name)

+	if err != nil {

+		t.Fatal(err)

+	}

+	defer os.RemoveAll(tmpdir)

+	ctx := filepath.Join(tmpdir, "context")

+	if err := os.MkdirAll(ctx, 0755); err != nil {

+		t.Fatal(err)

+	}

+	if err := ioutil.WriteFile(filepath.Join(ctx, "Dockerfile"), []byte(`

+	from busybox

+	add symlink.tar /

+	add inject /symlink/

+	`), 0644); err != nil {

+		t.Fatal(err)

+	}

+	inject := filepath.Join(ctx, "inject")

+	if err := ioutil.WriteFile(inject, nil, 0644); err != nil {

+		t.Fatal(err)

+	}

+	f, err := os.Create(filepath.Join(ctx, "symlink.tar"))

+	if err != nil {

+		t.Fatal(err)

+	}

+	w := tar.NewWriter(f)

+	w.WriteHeader(&tar.Header{

+		Name:     "symlink2",

+		Typeflag: tar.TypeSymlink,

+		Linkname: "/../../../../../../../../../../../../../../",

+		Uid:      os.Getuid(),

+		Gid:      os.Getgid(),

+	})

+	w.WriteHeader(&tar.Header{

+		Name:     "symlink",

+		Typeflag: tar.TypeSymlink,

+		Linkname: filepath.Join("symlink2", tmpdir),

+		Uid:      os.Getuid(),

+		Gid:      os.Getgid(),

+	})

+	w.Close()

+	f.Close()

+	if _, err := buildImageFromContext(name, &FakeContext{Dir: ctx}, false); err != nil {

+		t.Fatal(err)

+	}

+	if _, err := os.Lstat(filepath.Join(tmpdir, "inject")); err == nil {

+		t.Fatal("symlink breakout - inject")

+	} else if !os.IsNotExist(err) {

+		t.Fatalf("unexpected error: %v", err)

+	}

+	logDone("build - symlink breakout")

+}