avoid extra release of unowned objects in Parcel error path am: 7c8497e012 am:... (3e5f4dee) · Commits · e / os / android_frameworks_native

libs/binder/Parcel.cpp

+5 −3

Original line number	Diff line number	Diff line
		@@ -2202,12 +2202,14 @@ void Parcel::ipcSetDataReference(const uint8_t* data, size_t dataSize,
		type == BINDER_TYPE_FD)) {
		// We should never receive other types (eg BINDER_TYPE_FDA) as long as we don't support
		// them in libbinder. If we do receive them, it probably means a kernel bug; try to
		// recover gracefully by clearing out the objects, and releasing the objects we do
		// know about.
		// recover gracefully by clearing out the objects.
		android_errorWriteLog(0x534e4554, "135930648");
		android_errorWriteLog(0x534e4554, "203847542");
		ALOGE("%s: unsupported type object (%" PRIu32 ") at offset %" PRIu64 "\n",
		__func__, type, (uint64_t)offset);
		releaseObjects();

		// WARNING: callers of ipcSetDataReference need to make sure they
		// don't rely on mObjectsSize in their release_func.
		mObjectsSize = 0;
		break;
		}

libs/binder/tests/binderLibTest.cpp

+43 −3

Original line number	Diff line number	Diff line
		@@ -112,7 +112,7 @@ enum BinderLibTestTranscationCode {
		BINDER_LIB_TEST_NOP_TRANSACTION_WAIT,
		BINDER_LIB_TEST_GETPID,
		BINDER_LIB_TEST_ECHO_VECTOR,
		BINDER_LIB_TEST_REJECT_BUF,
		BINDER_LIB_TEST_REJECT_OBJECTS,
		BINDER_LIB_TEST_CAN_GET_SID,
		};

		@@ -1166,13 +1166,53 @@ TEST_F(BinderLibTest, BufRejected) {
		memcpy(parcelData, &obj, sizeof(obj));
		data.setDataSize(sizeof(obj));

		EXPECT_EQ(data.objectsCount(), 1);

		// Either the kernel should reject this transaction (if it's correct), but
		// if it's not, the server implementation should return an error if it
		// finds an object in the received Parcel.
		EXPECT_THAT(server->transact(BINDER_LIB_TEST_REJECT_BUF, data, &reply),
		EXPECT_THAT(server->transact(BINDER_LIB_TEST_REJECT_OBJECTS, data, &reply),
		Not(StatusEq(NO_ERROR)));
		}

		TEST_F(BinderLibTest, WeakRejected) {
		Parcel data, reply;
		sp<IBinder> server = addServer();
		ASSERT_TRUE(server != nullptr);

		auto binder = sp<BBinder>::make();
		wp<BBinder> wpBinder(binder);
		flat_binder_object obj{
		.hdr = {.type = BINDER_TYPE_WEAK_BINDER},
		.flags = 0,
		.binder = reinterpret_cast<uintptr_t>(wpBinder.get_refs()),
		.cookie = reinterpret_cast<uintptr_t>(wpBinder.unsafe_get()),
		};
		data.setDataCapacity(1024);
		// Write a bogus object at offset 0 to get an entry in the offset table
		data.writeFileDescriptor(0);
		EXPECT_EQ(data.objectsCount(), 1);
		uint8_t parcelData = const_cast<uint8_t >(data.data());
		// And now, overwrite it with the weak binder
		memcpy(parcelData, &obj, sizeof(obj));
		data.setDataSize(sizeof(obj));

		// a previous bug caused other objects to be released an extra time, so we
		// test with an object that libbinder will actually try to release
		EXPECT_EQ(OK, data.writeStrongBinder(sp<BBinder>::make()));

		EXPECT_EQ(data.objectsCount(), 2);

		// send it many times, since previous error was memory corruption, make it
		// more likely that the server crashes
		for (size_t i = 0; i < 100; i++) {
		EXPECT_THAT(server->transact(BINDER_LIB_TEST_REJECT_OBJECTS, data, &reply),
		StatusEq(BAD_VALUE));
		}

		EXPECT_THAT(server->pingBinder(), StatusEq(NO_ERROR));
		}

		TEST_F(BinderLibTest, GotSid) {
		sp<IBinder> server = addServer();

		@@ -1566,7 +1606,7 @@ public:
		reply->writeUint64Vector(vector);
		return NO_ERROR;
		}
		case BINDER_LIB_TEST_REJECT_BUF: {
		case BINDER_LIB_TEST_REJECT_OBJECTS: {
		return data.objectsCount() == 0 ? BAD_VALUE : NO_ERROR;
		}
		case BINDER_LIB_TEST_CAN_GET_SID: {