@mlinksva No credit given to others who deployed it and innovated with it much earlier but rather downplaying it and making misleading claims about it. It lowers our opinion of Apple's security team quite a lot. We got no credit for our July 2021 locked device auto-reboot when they did it in October 2024.

@mlinksva Yes, it does. They're shipped MTE version 4 years after Pixels shipped it and GrapheneOS enabled it in production. Version 4 of the feature set is needed to protect against certain side channels. It's strange to make jabs towards everyone who shipped the earlier versions and used it to protect users in protection (GrapheneOS). Apple has had a lot of severe side channels on their CPUs and will continue to have more, which may include ones impacting this feature too.

Being able to leak data via side channels is a known issue with modern CPUs with many rounds of issues being discovered and addressed. ARM has been working on fully resolving it for MTE itself. Apple CPUs have had much more severe issues with side channels than Cortex, so it's a strange jab by them.

There have been multiple revisions of ARM MTE. FEAT_MTE4 (Enhanced Memory Tagging Extension) is the 4th generation of ARM MTE improvements, not the beginning of it. The baseline feature was already a game changer for defending devices. The improvements will make their way to devices providing it.

Pixels have provided hardware memory tagging (MTE) support since the Pixel 8. GrapheneOS deployed it in production around a month after the launch of the Pixel 8 and we use it for the kernel and nearly the entire base OS. We use it for some third party apps and users can opt-in to using it for all.