Fix offset check in Parcel::hasFileDescriptorsInRange()
We should throw if the offset is equals to the data size since it's
zero-indexed.
Test: atest -d android.os.cts.ParcelTest
Change-Id: Ie93b6073ed9383ce8e0deeb78ffb50246fb5c3be
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index dee5309..7bb4e3e 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -547,21 +547,17 @@
return mHasFds;
}
-status_t Parcel::hasFileDescriptorsInRange(size_t offset, size_t len, bool& result) const {
+status_t Parcel::hasFileDescriptorsInRange(size_t offset, size_t len, bool* result) const {
if (len > INT32_MAX || offset > INT32_MAX) {
// Don't accept size_t values which may have come from an inadvertent conversion from a
// negative int.
return BAD_VALUE;
}
- size_t limit = offset + len;
- if (offset > mDataSize || len > mDataSize || limit > mDataSize || offset > limit) {
+ size_t limit;
+ if (__builtin_add_overflow(offset, len, &limit) || limit > mDataSize) {
return BAD_VALUE;
}
- result = hasFileDescriptorsInRangeUnchecked(offset, len);
- return NO_ERROR;
-}
-
-bool Parcel::hasFileDescriptorsInRangeUnchecked(size_t offset, size_t len) const {
+ *result = false;
for (size_t i = 0; i < mObjectsSize; i++) {
size_t pos = mObjects[i];
if (pos < offset) continue;
@@ -571,10 +567,11 @@
}
const flat_binder_object* flat = reinterpret_cast<const flat_binder_object*>(mData + pos);
if (flat->hdr.type == BINDER_TYPE_FD) {
- return true;
+ *result = true;
+ break;
}
}
- return false;
+ return NO_ERROR;
}
void Parcel::markSensitive() const
@@ -2567,9 +2564,9 @@
}
}
-void Parcel::scanForFds() const
-{
- mHasFds = hasFileDescriptorsInRangeUnchecked(0, dataSize());
+void Parcel::scanForFds() const {
+ status_t status = hasFileDescriptorsInRange(0, dataSize(), &mHasFds);
+ ALOGE_IF(status != NO_ERROR, "Error %d calling hasFileDescriptorsInRange()", status);
mFdsKnown = true;
}