MTE = Memory Tagging Extension

In mid-2022, Project Zero was provided with access to pre-production hardware implementing the ARM MTE specification. This blog post series is based on that review, and includes general conclusions about the effectiveness of MTE as implemented, specifically in the context of preventing the exploitation of memory-safety vulnerabilities.

Despite its limitations, MTE is still by far the most promising path forward for improving C/C++ software security in 2023. The ability of MTE to detect memory corruption exploitation at the first dangerous access provides a significant improvement in diagnostic and potential security effectiveness. In comparison, most other proposed approaches rely on blocking later stages in the exploitation process, for example various hardware-assisted CFI approaches which aim to block invalid control-flow transfers.

Implementation Testing

Mitigation Case Studies

The Kernel