Sven Peter

blog.svenpeter.dev

Apple’s new M1 SoC contains interesting and undocumented new hardware features. SPRR allows redefining the meaning of pagetable permission bits and GXF introduces lateral execution levels. This post explores these new features and documents how Apple uses them to protect macOS against attacks.

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Visit blog.svenpeter.dev → RSS feedOn Hacker News May 2021 – May 2021

Systems & Performance 1 Security & Privacy 1

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Apple Silicon Hardware: SPRR and Guarded Exception Levels (GXF)

2021272 points94 commentscited by 4Systems & Performance details

Over a year ago siguza published a write-up about Apple’s APRR - a custom ARM extension that redefines pagetable permissions and protects certain parts of the kernel from itself. Since then Apple has released their M1 chip which not only features an updated version of APRR but also easily allows to run bare-metal code…