Increment when attempting to read protected Parcel Data

Make sure to increment the parcel data position even when trying to
improperly read from protected data

Bug: 29833520

Test (M): cts-tradefed run cts -c android.os.cts.ParcelTest -m testBinderDataProtection
Test (M): cts-tradefed run cts -c android.os.cts.ParcelTest -m testBinderDataProtectionIncrements
Test: cts-tradefed run cts -m CtsOsTestCases -t android.os.cts.ParcelTest#testBinderDataProtection
Test: cts-tradefed run cts -m CtsOsTestCases -t android.os.cts.ParcelTest#testBinderDataProtectionIncrements

Change-Id: Ie4aae6277fc5f5c924f603d9828c3a608998b986
Merged-In: Ie4aae6277fc5f5c924f603d9828c3a608998b986

1 files changed, 17 insertions, 3 deletions

diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index ef14475ae2..9f68e7aa8c 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -1125,7 +1125,12 @@ status_t Parcel::read(void* outData, size_t len) const
             && len <= pad_size(len)) {
         if (mObjectsSize > 0) {
             status_t err = validateReadData(mDataPos + pad_size(len));
-            if(err != NO_ERROR) return err;
+            if(err != NO_ERROR) {
+                // Still increment the data position by the expected length
+                mDataPos += pad_size(len);
+                ALOGV("read Setting data pos of %p to %zu", this, mDataPos);
+                return err;
+            }
         }
         memcpy(outData, mData+mDataPos, len);
         mDataPos += pad_size(len);
@@ -1147,7 +1152,12 @@ const void* Parcel::readInplace(size_t len) const
             && len <= pad_size(len)) {
         if (mObjectsSize > 0) {
             status_t err = validateReadData(mDataPos + pad_size(len));
-            if(err != NO_ERROR) return NULL;
+            if(err != NO_ERROR) {
+                // Still increment the data position by the expected length
+                mDataPos += pad_size(len);
+                ALOGV("readInplace Setting data pos of %p to %zu", this, mDataPos);
+                return NULL;
+            }
         }
 
         const void* data = mData+mDataPos;
@@ -1165,7 +1175,11 @@ status_t Parcel::readAligned(T *pArg) const {
     if ((mDataPos+sizeof(T)) <= mDataSize) {
         if (mObjectsSize > 0) {
             status_t err = validateReadData(mDataPos + sizeof(T));
-            if(err != NO_ERROR) return err;
+            if(err != NO_ERROR) {
+                // Still increment the data position by the expected length
+                mDataPos += sizeof(T);
+                return err;
+            }
         }
 
         const void* data = mData+mDataPos;