SurfaceFlinger: Validate layers before casting.
Reinterpret casting random IBinder = no-fun. I first attempted
to use inheritance of "getInterfaceDescriptor" in Layer::Handle but
departing from "standard-layout" (e.g. using virtual methods) means that
downcasting with static/reinterpret_cast is no longer valid. Instead I opted
for the pattern the system-server uses of maintaing a map.
Bug: 129768960
Test: InvalidHandles_test.cpp
Change-Id: Ica8d08a2daf5e80d187e818adbff0c7901db69f7
diff --git a/services/surfaceflinger/tests/Android.bp b/services/surfaceflinger/tests/Android.bp
index f121a95..d3c87bf 100644
--- a/services/surfaceflinger/tests/Android.bp
+++ b/services/surfaceflinger/tests/Android.bp
@@ -19,6 +19,7 @@
srcs: [
"BufferGenerator.cpp",
"Credentials_test.cpp",
+ "InvalidHandles_test.cpp",
"Stress_test.cpp",
"SurfaceInterceptor_test.cpp",
"Transaction_test.cpp",
diff --git a/services/surfaceflinger/tests/InvalidHandles_test.cpp b/services/surfaceflinger/tests/InvalidHandles_test.cpp
new file mode 100644
index 0000000..42d1f5a
--- /dev/null
+++ b/services/surfaceflinger/tests/InvalidHandles_test.cpp
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <binder/Binder.h>
+
+#include <gtest/gtest.h>
+
+#include <gui/ISurfaceComposer.h>
+#include <gui/SurfaceComposerClient.h>
+#include <private/gui/ComposerService.h>
+#include <ui/Rect.h>
+
+namespace android {
+namespace {
+
+class NotALayer : public BBinder {};
+
+/**
+ * For all of these tests we make a SurfaceControl with an invalid layer handle
+ * and verify we aren't able to trick SurfaceFlinger.
+ */
+class InvalidHandleTest : public ::testing::Test {
+protected:
+ sp<SurfaceComposerClient> mScc;
+ sp<SurfaceControl> mNotSc;
+ void SetUp() override {
+ mScc = new SurfaceComposerClient;
+ ASSERT_EQ(NO_ERROR, mScc->initCheck());
+ mNotSc = makeNotSurfaceControl();
+ }
+
+ sp<SurfaceControl> makeNotSurfaceControl() {
+ return new SurfaceControl(mScc, new NotALayer(), nullptr, true);
+ }
+};
+
+TEST_F(InvalidHandleTest, createSurfaceInvalidHandle) {
+ auto notSc = makeNotSurfaceControl();
+ ASSERT_EQ(nullptr,
+ mScc->createSurface(String8("lolcats"), 19, 47, PIXEL_FORMAT_RGBA_8888, 0,
+ notSc.get())
+ .get());
+}
+
+TEST_F(InvalidHandleTest, captureLayersInvalidHandle) {
+ sp<ISurfaceComposer> sf(ComposerService::getComposerService());
+ sp<GraphicBuffer> outBuffer;
+
+ ASSERT_EQ(NAME_NOT_FOUND,
+ sf->captureLayers(mNotSc->getHandle(), &outBuffer, Rect::EMPTY_RECT, 1.0f));
+}
+
+} // namespace
+} // namespace android
diff --git a/services/surfaceflinger/tests/SurfaceFlinger_test.filter b/services/surfaceflinger/tests/SurfaceFlinger_test.filter
index be862c9..a8d09ea 100644
--- a/services/surfaceflinger/tests/SurfaceFlinger_test.filter
+++ b/services/surfaceflinger/tests/SurfaceFlinger_test.filter
@@ -1,5 +1,5 @@
{
"presubmit": {
- "filter": "CredentialsTest.*:SurfaceFlingerStress.*:SurfaceInterceptorTest.*:LayerTransactionTest.*:LayerTypeTransactionTest.*:LayerUpdateTest.*:GeometryLatchingTest.*:CropLatchingTest.*:ChildLayerTest.*:ScreenCaptureTest.*:ScreenCaptureChildOnlyTest.*:DereferenceSurfaceControlTest.*:BoundlessLayerTest.*:MultiDisplayLayerBoundsTest.*"
+ "filter": "CredentialsTest.*:SurfaceFlingerStress.*:SurfaceInterceptorTest.*:LayerTransactionTest.*:LayerTypeTransactionTest.*:LayerUpdateTest.*:GeometryLatchingTest.*:CropLatchingTest.*:ChildLayerTest.*:ScreenCaptureTest.*:ScreenCaptureChildOnlyTest.*:DereferenceSurfaceControlTest.*:BoundlessLayerTest.*:MultiDisplayLayerBoundsTest.*:InvalidHandleTest.*"
}
}