Nice to know that all supported Pixel phones are not only on the same kernel version, but actually are build fro the same source tree now.
Do you also contribute your fixes back to the upstream projects like the upstream Linux kernel, AOSP or Google?
Many of the security features you are using are already included in AOSP, why does Google not activate them by default? Do they have a different balancing of performance, stability and compatibility on the one side and security on the other?
I understand that Google has a different view on privacy for business reasons.
> Do you also contribute your fixes back to the upstream projects like the upstream Linux kernel, AOSP or Google?
We've made significant contributions to the Linux kernel, AOSP and Pixels in the past. We continue doing it to the extent that it helps GrapheneOS users. We no longer spend our time doing work for them if it doesn't have a clear benefit to our users.
Android's security team previously got us security partner access and was in the process of getting us OEM partner access. Android's partner management team blocked us from getting OEM partner access and revoked our security partner access. Due to this, we've reduced our reports of vulnerabilities upstream and have fixed numerous vulnerabilities in GrapheneOS without reporting them. We still report all firmware and hardware vulnerabilities but we make a decision about reporting software vulnerabilities solely based on what's best for GrapheneOS users.
> Many of the security features you are using are already included in AOSP
That's not really the case. The vast majority of our privacy and security features were developed for GrapheneOS. Features being built on top of standard functionality doesn't mean that they're present in AOSP.
For example, GrapheneOS has our own integration of hardware memory tagging into our hardened_malloc project and we turned the overall feature into something which can be used in production without making the OS unusable. We had to fix issues with the standard hardware memory tagging integration in the OS and Vanadium (Chromium) along with fixing numerous bugs uncovered by it. We had to integrate it into our user-facing crash reporting system and had to create a system for opting into using it for user installed apps where users can enable it for either specific user installed apps or for all user installed apps with a per-app opt-out. Android has the foundation for hardware memory tagging support but it's not used as a production feature for hardening and we're not simply enabling it. We have a much better userspace implementation in hardened_malloc and while we currently use the standard kernel allocator integration, we want to improve that to be closer to what we do with it in hardened_malloc. We currently use the standard Linux kernel MTE integration for the kernel allocators and the standard Chromium PartitionAlloc MTE integration but both need to be improved to provide better security properties as hardened_malloc does. They're also missing the other forms of hardening used by hardened_malloc which go nicely with memory tagging. The stock OS developer option for memory tagging is not the same thing and only makes it available for usage without actually using it. It has to then be enabled via ADB but there's no way to use it everywhere we do or in the same way we do. AOSP having that doesn't mean it provides what we do with it at all.
> Do they have a different balancing of performance, stability and compatibility on the one side and security on the other?
Yes, but you're wrong about where our privacy and security features come from.
Nice to know that all supported Pixel phones are not only on the same kernel version, but actually are build fro the same source tree now.
Do you also contribute your fixes back to the upstream projects like the upstream Linux kernel, AOSP or Google?
Many of the security features you are using are already included in AOSP, why does Google not activate them by default? Do they have a different balancing of performance, stability and compatibility on the one side and security on the other? I understand that Google has a different view on privacy for business reasons.