GrapheneOS: Pixel 11 Loses MTE Hardware Memory Protection

The developers of the security-focused mobile OS GrapheneOS have announced on their account on the Bluesky social network that Google's new generation of smartphones — the Pixel 11 — no longer supports hardware memory tagging (Memory Tagging Extension, MTE).

MTE is a hardware feature of the ARM architecture designed to detect and prevent an entire class of memory errors: accesses to already-freed regions, buffer overruns and other forms of corruption that have traditionally served as fertile ground for exploits. It is precisely this mechanism that GrapheneOS and a number of protective subsystems in modern Android devices have relied on as one of their key lines of defense.

The disappearance of MTE support in the Pixel 11 is notable news above all for those to whom device security matters. The Pixel line long remained the reference platform for GrapheneOS, in large part thanks to its combination of openness and the availability of modern hardware protections, including MTE. Dropping this capability in the new generation calls into question the continuity of that approach.

The GrapheneOS statement is terse and, for now, comes with no detailed technical elaboration, so it is premature to draw far-reaching conclusions about the reasons behind Google's decision. Nonetheless, the mere acknowledgment of the fact has sparked lively discussion in the community: the post quickly drew responses on Hacker News.

For users, this is a reason to keep a closer eye on further comments from both the GrapheneOS project and Google — the assessment of how secure the new smartphone line is will depend on exactly what explains the absence of MTE and whether an alternative will be offered.

Source: Hacker News