Mitigating Linux kernel memory corruptions with Arm Memory Tagging | Linux Security Summit 2021

Memory tagging is coming to kill all of your favorite Linux kernel exploits! Memory Tagging Extension (MTE) is an ARM v8.5 feature that enables hardware-assisted validation of the correctness of memory accesses. In a nutshell, MTE allows assigning tags to memory allocations, as well as to pointers that refer to those allocations. When a pointer is accessed, the CPU performs a validity check that ensures that the memory tag matches the pointer tag. In this talk, I explain how MTE is used to assert the validity of kernel memory accesses. I describe the newly added Hardware Tag-Based KASAN mode, its weaknesses, and planned improvements. Slides: Twitter: Website: 00:00 Intro 03:16 Memory tagging 04:49 Arm Memory Tagging Extension 10:28 In-kernel MTE or Hardware Tag-Based KASAN 13:19 Preventing memory corruptions