commit 2a1e241d8042c3df6e191462d384580bd0358977
author Steven Moreland <smoreland@google.com> Thu Mar 10 23:34:07 2022 +0000
committer Steven Moreland <smoreland@google.com> Mon Mar 14 18:05:51 2022 +0000
tree 10d8120c8ed9cb79647ee226819fb401264d76b7
parent 2362edf7a6c9c7d756d6e573c4d44837e16fed36

libbinder*: ParcelableHolder assert stability read

The interface a ParcelableHolder is in determines its stability,
and it shouldn't change based on what is sent.

Bug: 215458170
Test: aidl_integration_test
Change-Id: I35f1342edc9f3dc40e2553a4eaf386f67a9fbaa1

libs/binder/ParcelableHolder.cpp

diff --git a/libs/binder/ParcelableHolder.cpp b/libs/binder/ParcelableHolder.cpp
index 2e86b74..3cf94e3 100644
--- a/libs/binder/ParcelableHolder.cpp
+++ b/libs/binder/ParcelableHolder.cpp
@@ -52,7 +52,10 @@
 }
 
 status_t ParcelableHolder::readFromParcel(const Parcel* p) {
-    this->mStability = static_cast<Stability>(p->readInt32());
+    int32_t wireStability;
+    if (status_t status = p->readInt32(&wireStability); status != OK) return status;
+    if (static_cast<int32_t>(this->mStability) != wireStability) return BAD_VALUE;
+
     this->mParcelable = nullptr;
     this->mParcelableName = std::nullopt;
     int32_t rawDataSize;

libs/binder/ndk/include_cpp/android/binder_parcelable_utils.h

diff --git a/libs/binder/ndk/include_cpp/android/binder_parcelable_utils.h b/libs/binder/ndk/include_cpp/android/binder_parcelable_utils.h
index 28819bb..f45aa76 100644
--- a/libs/binder/ndk/include_cpp/android/binder_parcelable_utils.h
+++ b/libs/binder/ndk/include_cpp/android/binder_parcelable_utils.h
@@ -101,7 +101,12 @@
             return STATUS_INVALID_OPERATION;
         }
 
-        RETURN_ON_FAILURE(AParcel_readInt32(parcel, &this->mStability));
+        parcelable_stability_t wireStability;
+        RETURN_ON_FAILURE(AParcel_readInt32(parcel, &wireStability));
+        if (this->mStability != wireStability) {
+            return STATUS_BAD_VALUE;
+        }
+
         int32_t dataSize;
         binder_status_t status = AParcel_readInt32(parcel, &dataSize);
 

libs/binder/rust/src/parcel/parcelable_holder.rs

diff --git a/libs/binder/rust/src/parcel/parcelable_holder.rs b/libs/binder/rust/src/parcel/parcelable_holder.rs
index d58e839..432da5d 100644
--- a/libs/binder/rust/src/parcel/parcelable_holder.rs
+++ b/libs/binder/rust/src/parcel/parcelable_holder.rs
@@ -233,7 +233,9 @@
     }
 
     fn read_from_parcel(&mut self, parcel: &BorrowedParcel<'_>) -> Result<(), StatusCode> {
-        self.stability = parcel.read()?;
+        if self.stability != parcel.read()? {
+            return Err(StatusCode::BAD_VALUE);
+        }
 
         let data_size: i32 = parcel.read()?;
         if data_size < 0 {