Merge "Disallow reading object data from Parcels with non-object reads" (981dcd46) · Commits · e / os / android_frameworks_native-old

libs/binder/Parcel.cpp

+73 −0

Original line number	Diff line number	Diff line
		@@ -433,6 +433,7 @@ void Parcel::setDataPosition(size_t pos) const

		mDataPos = pos;
		mNextObjectHint = 0;
		mObjectsSorted = false;
		}

		status_t Parcel::setDataCapacity(size_t size)
		@@ -1469,6 +1470,59 @@ void Parcel::remove(size_t /start/, size_t /amt/)
		LOG_ALWAYS_FATAL("Parcel::remove() not yet implemented!");
		}

		status_t Parcel::validateReadData(size_t upperBound) const
		{
		// Don't allow non-object reads on object data
		if (mObjectsSorted \|\| mObjectsSize <= 1) {
		data_sorted:
		// Expect to check only against the next object
		if (mNextObjectHint < mObjectsSize && upperBound > mObjects[mNextObjectHint]) {
		// For some reason the current read position is greater than the next object
		// hint. Iterate until we find the right object
		size_t nextObject = mNextObjectHint;
		do {
		if (mDataPos < mObjects[nextObject] + sizeof(flat_binder_object)) {
		// Requested info overlaps with an object
		ALOGE("Attempt to read from protected data in Parcel %p", this);
		return PERMISSION_DENIED;
		}
		nextObject++;
		} while (nextObject < mObjectsSize && upperBound > mObjects[nextObject]);
		mNextObjectHint = nextObject;
		}
		return NO_ERROR;
		}
		// Quickly determine if mObjects is sorted.
		binder_size_t* currObj = mObjects + mObjectsSize - 1;
		binder_size_t* prevObj = currObj;
		while (currObj > mObjects) {
		prevObj--;
		if(prevObj > currObj) {
		goto data_unsorted;
		}
		currObj--;
		}
		mObjectsSorted = true;
		goto data_sorted;

		data_unsorted:
		// Insertion Sort mObjects
		// Great for mostly sorted lists. If randomly sorted or reverse ordered mObjects become common,
		// switch to std::sort(mObjects, mObjects + mObjectsSize);
		for (binder_size_t* iter0 = mObjects + 1; iter0 < mObjects + mObjectsSize; iter0++) {
		binder_size_t temp = *iter0;
		binder_size_t* iter1 = iter0 - 1;
		while (iter1 >= mObjects && *iter1 > temp) {
		(iter1 + 1) = iter1;
		iter1--;
		}
		*(iter1 + 1) = temp;
		}
		mNextObjectHint = 0;
		mObjectsSorted = true;
		goto data_sorted;
		}

		status_t Parcel::read(void* outData, size_t len) const
		{
		if (len > INT32_MAX) {
		@@ -1479,6 +1533,10 @@ status_t Parcel::read(void* outData, size_t len) const

		if ((mDataPos+pad_size(len)) >= mDataPos && (mDataPos+pad_size(len)) <= mDataSize
		&& len <= pad_size(len)) {
		if (mObjectsSize > 0) {
		status_t err = validateReadData(mDataPos + pad_size(len));
		if(err != NO_ERROR) return err;
		}
		memcpy(outData, mData+mDataPos, len);
		mDataPos += pad_size(len);
		ALOGV("read Setting data pos of %p to %zu", this, mDataPos);
		@@ -1497,6 +1555,11 @@ const void* Parcel::readInplace(size_t len) const

		if ((mDataPos+pad_size(len)) >= mDataPos && (mDataPos+pad_size(len)) <= mDataSize
		&& len <= pad_size(len)) {
		if (mObjectsSize > 0) {
		status_t err = validateReadData(mDataPos + pad_size(len));
		if(err != NO_ERROR) return NULL;
		}

		const void* data = mData+mDataPos;
		mDataPos += pad_size(len);
		ALOGV("readInplace Setting data pos of %p to %zu", this, mDataPos);
		@@ -1510,6 +1573,11 @@ status_t Parcel::readAligned(T *pArg) const {
		COMPILE_TIME_ASSERT_FUNCTION_SCOPE(PAD_SIZE_UNSAFE(sizeof(T)) == sizeof(T));

		if ((mDataPos+sizeof(T)) <= mDataSize) {
		if (mObjectsSize > 0) {
		status_t err = validateReadData(mDataPos + sizeof(T));
		if(err != NO_ERROR) return err;
		}

		const void* data = mData+mDataPos;
		mDataPos += sizeof(T);
		pArg = reinterpret_cast<const T*>(data);
		@@ -2366,6 +2434,7 @@ void Parcel::ipcSetDataReference(const uint8_t* data, size_t dataSize,
		mObjects = const_cast<binder_size_t*>(objects);
		mObjectsSize = mObjectsCapacity = objectsCount;
		mNextObjectHint = 0;
		mObjectsSorted = false;
		mOwner = relFunc;
		mOwnerCookie = relCookie;
		for (size_t i = 0; i < mObjectsSize; i++) {
		@@ -2524,6 +2593,7 @@ status_t Parcel::restartWrite(size_t desired)
		mObjects = NULL;
		mObjectsSize = mObjectsCapacity = 0;
		mNextObjectHint = 0;
		mObjectsSorted = false;
		mHasFds = false;
		mFdsKnown = true;
		mAllowFds = true;
		@@ -2610,6 +2680,7 @@ status_t Parcel::continueWrite(size_t desired)
		mDataCapacity = desired;
		mObjectsSize = mObjectsCapacity = objectsSize;
		mNextObjectHint = 0;
		mObjectsSorted = false;

		} else if (mData) {
		if (objectsSize < mObjectsSize) {
		@@ -2631,6 +2702,7 @@ status_t Parcel::continueWrite(size_t desired)
		}
		mObjectsSize = objectsSize;
		mNextObjectHint = 0;
		mObjectsSorted = false;
		}

		// We own the data, so we can just do a realloc().
		@@ -2703,6 +2775,7 @@ void Parcel::initState()
		mObjectsSize = 0;
		mObjectsCapacity = 0;
		mNextObjectHint = 0;
		mObjectsSorted = false;
		mHasFds = false;
		mFdsKnown = true;
		mAllowFds = true;

libs/binder/include/binder/Parcel.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -417,6 +417,7 @@ private:
		void freeDataNoInit();
		void initState();
		void scanForFds() const;
		status_t validateReadData(size_t len) const;

		template<class T>
		status_t readAligned(T *pArg) const;
		@@ -463,6 +464,7 @@ private:
		size_t mObjectsSize;
		size_t mObjectsCapacity;
		mutable size_t mNextObjectHint;
		mutable bool mObjectsSorted;

		mutable bool mFdsKnown;
		mutable bool mHasFds;