AHEMS: Asynchronous Hardware-Enforced Memory Safety

This paper presents AHEMS (Asynchronous Hardware-Enforced Memory Safety), an architectural support for enforcing spatial and temporal memory safety to protect against memory corruption attacks. We integrated AHEMS with the Leon3 open-source processor and prototype on an FPGA. In an evaluation of the detection coverage using 677 security test cases (including spatial and temporal memory errors), selected from the Juliet Test Suite, AHEMS detected all but one memory safety violation. The missed test case involves overflow of a sub-object in a data structure whose detection is not supported by the current prototype. Performance assessment using the Olden benchmarks shows an average 10.6% overhead, and negligible impact on the processor-critical path (0.06% overhead) and power consumption (0.5% overhead).