fprime: F´: File size bounds bypass in Svc::FileUplink via unsigned integer overflow in DATA packet validation

F´ (F Prime) is a framework that enables development and deployment of spaceflight and other embedded software applications. Prior to 4.2.0, Svc::FileUplink handleDataPacket offset and size validation is vulnerable because the component checks byteOffset plus dataSize with wrapping U32 arithmetic and then seeks to the large attacker-controlled offset before writing. When a file-uplink DATA packet supplies a byteOffset and dataSize whose unsigned sum wraps below the declared file size, data can be written beyond the declared upload size, causing file integrity loss and potentially large sparse-file growth or resource exhaustion. This issue is fixed in version 4.2.0.