Don't use writeByteArray() in xposed_service.cpp

romracer · rovo89 · commit 46cedbc885e1 · 2015-09-02T19:45:31.000+02:00
This works around an AOSP bug. Byte arrays first store the array size and then the bytes. However, Parcel::writeByteArray() uses size_t for the size, whereas all other parts related to Parcels read/write int32_t values. This leads to conflicts on 64-bit ROMs, as size_t uses 4 bytes instead of 4 bytes here. In Xposed, this results in invalid file reads, most notably in XSharedPreferences. This fixes rovo89/XposedBridge#58. Thanks to @rsteckler for reporting this issue and testing the fix!
diff --git a/xposed_service.cpp b/xposed_service.cpp
@@ -581,12 +581,8 @@ status_t BnXposedService::onTransact(uint32_t code, const Parcel& data, Parcel*
             reply->writeInt64(size);
             reply->writeInt64(mtime);
             if (bytesRead > 0) {
-#if PLATFORM_SDK_VERSION >= 21
-                reply->writeByteArray(bytesRead, buffer);
-#else
                 reply->writeInt32(bytesRead);
                 reply->write(buffer, bytesRead);
-#endif
                 free(buffer);
             } else {
                 reply->writeInt32(bytesRead); // empty array (0) or null (-1)
