In 2018, chip designer Arm introduced a hardware security feature called Memory Tagging Extensions (MTE) as a defense against memory security bugs. But it may not be as effective as first hoped.
researchers find an unfixable bug in EVERY ARM processor
MTE, which was implemented and supported last year in Google's Pixel 8 and Pixel 8 Pro phones and previously in Linux, aims to help detect memory security breaches, as well as harden devices against attacks that attempt to exploit memory security flaws.
Memory security bugs are said to be responsible for the majority of security flaws in large codebases. And in recent years, there has been a concerted effort in the public and private sectors to reduce such shortcomings by promoting memory-safe programming languages, software-based code hardening techniques, and hardware-specific alternatives such as SPARC ADI and Arm MTE.
MTE works by tagging blocks of physical memory with metadata. This metadata acts as a key that allows access. When a pointer references data in a tagged memory block, the hardware checks that the pointer contains a key that matches the memory block's key to access the data. A mismatch results in an error.
