Prevent integer overflow when calculating buffer resizes
Make sure that we don't go haywire if an exponential buffer growth
operation winds up wrapping integer range. Along the way, fix a
bookkeeping bug in BufferedTextOutput that would cause it to keep
spuriously realloc()ing on every append().
Bug 20674694
Change-Id: Ia845b7de36b90672a151a918ffc26c7da68e20a2
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index 2ebf617..31667d9 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -484,7 +484,8 @@
if (numObjects > 0) {
// grow objects
if (mObjectsCapacity < mObjectsSize + numObjects) {
- int newSize = ((mObjectsSize + numObjects)*3)/2;
+ size_t newSize = ((mObjectsSize + numObjects)*3)/2;
+ if (newSize < mObjectsSize) return NO_MEMORY; // overflow
binder_size_t *objects =
(binder_size_t*)realloc(mObjects, newSize*sizeof(binder_size_t));
if (objects == (binder_size_t*)0) {
@@ -1038,6 +1039,7 @@
}
if (!enoughObjects) {
size_t newSize = ((mObjectsSize+2)*3)/2;
+ if (newSize < mObjectsSize) return NO_MEMORY; // overflow
binder_size_t* objects = (binder_size_t*)realloc(mObjects, newSize*sizeof(binder_size_t));
if (objects == NULL) return NO_MEMORY;
mObjects = objects;