[automerger] Disallow reading object data from Parcels with non-object reads am: f784183c17 am: c6ae5cf9c5 am: 22b5950994 am: f4dc4cd4a3 am: 81a160b19e am: 2d14de5c70 am: 9f92221278 am: 2de1de1499
Change-Id: Id8d3aa4511e46c119e1a59a9c50d5f47164600bc
diff --git a/include/binder/Parcel.h b/include/binder/Parcel.h
index 2490b82..6ea8453 100644
--- a/include/binder/Parcel.h
+++ b/include/binder/Parcel.h
@@ -375,6 +375,7 @@
void freeDataNoInit();
void initState();
void scanForFds() const;
+ status_t validateReadData(size_t len) const;
template<class T>
status_t readAligned(T *pArg) const;
@@ -421,6 +422,7 @@
size_t mObjectsSize;
size_t mObjectsCapacity;
mutable size_t mNextObjectHint;
+ mutable bool mObjectsSorted;
mutable bool mFdsKnown;
mutable bool mHasFds;
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index 19ce3eb..e5a9346 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -459,6 +459,7 @@
mDataPos = pos;
mNextObjectHint = 0;
+ mObjectsSorted = false;
}
status_t Parcel::setDataCapacity(size_t size)
@@ -1363,6 +1364,59 @@
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) {
@@ -1373,6 +1427,10 @@
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);
@@ -1391,6 +1449,11 @@
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);
@@ -1404,6 +1467,11 @@
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);
@@ -2206,6 +2274,7 @@
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++) {
@@ -2364,6 +2433,7 @@
mObjects = NULL;
mObjectsSize = mObjectsCapacity = 0;
mNextObjectHint = 0;
+ mObjectsSorted = false;
mHasFds = false;
mFdsKnown = true;
mAllowFds = true;
@@ -2450,6 +2520,7 @@
mDataCapacity = desired;
mObjectsSize = mObjectsCapacity = objectsSize;
mNextObjectHint = 0;
+ mObjectsSorted = false;
} else if (mData) {
if (objectsSize < mObjectsSize) {
@@ -2471,6 +2542,7 @@
}
mObjectsSize = objectsSize;
mNextObjectHint = 0;
+ mObjectsSorted = false;
}
// We own the data, so we can just do a realloc().
@@ -2543,6 +2615,7 @@
mObjectsSize = 0;
mObjectsCapacity = 0;
mNextObjectHint = 0;
+ mObjectsSorted = false;
mHasFds = false;
mFdsKnown = true;
mAllowFds = true;