Clear the Parcel before writing an exception during a transaction

This prevents any object data from being accidentally overwritten by the
exception, which could cause unexpected malformed objects to be sent
across the transaction.

Test: atest CtsOsTestCases:ParcelTest#testExceptionOverwritesObject
Bug: 34175893
Change-Id: Iaf80a0ad711762992b8ae60f76d861c97a403013
Merged-In: Iaf80a0ad711762992b8ae60f76d861c97a403013
(cherry picked from commit f8ef5bcf21c87d8617f5e11810cc94350298d114)
diff --git a/core/java/android/os/ b/core/java/android/os/
index ff0bc69..b9e2119 100644
--- a/core/java/android/os/
+++ b/core/java/android/os/
@@ -683,6 +683,8 @@
                     Log.w(TAG, "Caught a RuntimeException from the binder stub implementation.", e);
             } else {
+                // Clear the parcel before writing the exception
+                reply.setDataSize(0);