It's available since October 2023 when it launched on the Pixel 8. We integrated it into hardened_malloc that month and deployed it in production. We've been working on further research and improvements based on MTE since then.
GrapheneOS always uses it for the kernel, all of the base OS processes including apps with a couple exceptions, user installed apps opting into it and user installed apps solely written in Java/Kotlin which are very common on Android. For other user installed apps, there's a toggle for users to opt-in and most apps work with it already. For apps not known to work with it, there's a user-facing system for MTE crash reports and users can make an exception. Users can't disable it for base OS apps or apps which should work due to opting in or being pure Java/Kotlin.
Apple uses it for the kernel and parts of the base OS. They require opt-in by app developers and discourage doing it.
GrapheneOS is working on improvements to the kernel integration, Chromium PartitionAlloc integration and other aspects of it. We'll enable enforcement of tags for untagged memory once that's available, but we're also expanding the tagging. As an example, fully enabling stack allocation tagging has a more than acceptable performance cost for GrapheneOS but not Apple or Google. That's something we've been actively testing and will be deploying.
GrapheneOS always uses it for the kernel, all of the base OS processes including apps with a couple exceptions, user installed apps opting into it and user installed apps solely written in Java/Kotlin which are very common on Android. For other user installed apps, there's a toggle for users to opt-in and most apps work with it already. For apps not known to work with it, there's a user-facing system for MTE crash reports and users can make an exception. Users can't disable it for base OS apps or apps which should work due to opting in or being pure Java/Kotlin.
Apple uses it for the kernel and parts of the base OS. They require opt-in by app developers and discourage doing it.
GrapheneOS is working on improvements to the kernel integration, Chromium PartitionAlloc integration and other aspects of it. We'll enable enforcement of tags for untagged memory once that's available, but we're also expanding the tagging. As an example, fully enabling stack allocation tagging has a more than acceptable performance cost for GrapheneOS but not Apple or Google. That's something we've been actively testing and will be deploying.