We have a partial port of GrapheneOS to the Pixel 11 series after a week of work on it. We’re unable to complete the port due to lack of support for ARM hardware memory tagging in software, firmware and near certainly hardware. It appears Google cut an important security feature to save money.
ARM hardware memory tagging (MTE) is used by GrapheneOS across the entire base OS including the kernel and every standard base OS process. It’s only temporarily disabled for a few device-specific processes. It greatly improves protection against nearly all remote exploits and many local exploits.
Pixel 8 launched with hardware MTE support in October 2023. We integrated it into our hardened_malloc project and began using it across the OS later that month. Android and the Pixel OS never started using it by default. Android Advanced Protection Mode in Android 16 enables it for a few processes.
Apple’s Memory Integrity Enforcement (MIE) is an always enabled feature on the iPhone 17. It’s simply a high quality implementation of MTE using the latest standard extensions. It uses MTE in the most secure mode in the kernel and a large portion of userbase. They did a very good job integrating it.
Apple’s MIE and Android 16+ AAPM don’t use MTE for user installed apps unless those explicitly opt in. GrapheneOS enables it for more apps automatically and has a toggle for users to opt-in for every user installed app. There’s a per-app toggle to opt-out for incompatible apps which is uncommon.
Neither iOS or Android encourage app developers to opt into MTE and other more aggressive security features used in the base OS. Apple’s docs warn developers of performance and stability issues. Even Signal doesn’t opt-in. Our approach enables forcing using MTE in the standard allocators regardless.
Pixel 11 does have security improvements including moving to post-quantum secure verified boot (ML-DSA) and replacing Samsung Shannon IMS with AOSP IMS. Titan M3 should significantly improve protection against data extraction in Before First Unlock state. It’s too bad they ruined it by cutting MTE.
Pixel 11 series is a lot more expensive for an incremental improvement to the CPU, the same underpowered GPU and reduced RAM for the Pro base models. They finally caught up to the last generation of Qualcomm cellular radio. It’s overpriced, the upgrades aren’t impressive and losing MTE is appalling.
Compared to the Pixel 11, a Snapdragon 8 Elite Gen 5 has 40% higher single threaded CPU performance, 80% higher multi threaded performance, over 100% higher GPU performance and a far better cellular radio. It also finally has MTE. The next gen is what will be in the first Motorola with GrapheneOS.
Pixel 9a and earlier (including Nexus devices) were the Android Open Source Project reference devices. Pixel support was removed from AOSP with Android 16. It’s now harder to support Pixels than many other devices and massive progress towards open source firmware and driver libraries was discarded.
Compared to the stock Pixel OS, GrapheneOS ships AOSP patches months earlier and Linux kernel patches many months earlier. However, we rely on them for firmware and most driver updates. We also want to move to new kernel branches earlier. These things can be improved with our Motorola partnership.
We strongly recommend against buying Pixel 11 devices. Pixel 8, 9 and 10 have much better overall security for GrapheneOS. Pixel 10 is cheaper with similar hardware and MTE. Pixel 11’s Titan M3 should improve BFU security for users without a strong passphrase, but losing MTE craters AFU security.
We haven’t determined what to do about this situation. It may be best for us to skip the Pixel 11 series devices. We can shift our focus entirely to the upcoming Motorola devices instead. Pixel 10a was really a 9th gen Pixel, so hopefully the Pixel 11a does the same with 10th gen and includes MTE.
I like the idea of a linux phone, but do current options measure up to GrapheneOS in terms of security? My uninformed impression is they don’t?
(And don’t make me tap the security through obscurity sign.)
Nothing can match GOS when it comes to security.
You also don’t need that much security (before you get mad at me, check if you don’t have a desktop PC somewhere in your house).
No, not even desktop Linux. GrapheneOS is the most secure OS that I’m aware of. Android desktop mode has me a little excited. It’s not bad right now, but I wouldn’t want to work on it all day.
Graphene OS is the most secure OS, and it’s been proven. Not even that infamous Israeli cracking software can get into it.
I don’t think cellebrite even tries to get into desktop OS’s. I don’t know if there is a tool that targets both that has leaked lists of successful targets like cellebrite that would be a good comparison.
Graphene is definitely more secure than default popular Linux distributions, but there are probably some install scripts out there that make it about equally secure.
What about QubesOS?
QubesOS is interesting. It basically throws every application in it’s own VM and firewalls each other off. It’s not a bad strategy at all, and they’ve integrated everything neatly, but it’s not hardened like GrapheneOS. It’s not something I’d personally want to daily drive, especially on a laptop, but neither is Android Desktop.
What do you mean it’s not hardened like GrapheneOS? Throwing everything in isolated VMs is the same approach that the Xbox consoles have taken since the Xbox One, and those still haven’t been hacked, save for a bootrom exploit via glitching in the original model of the Xbox One before the OS loads. If one VM (or “qube” in this case) gets compromised, it is sandboxed from the rest of the machine, and no user-installed application runs on the host OS (dom0), save for what comes preinstalled, like settings applications and the GUI, and none of that touches the Internet.
Not wanting to daily drive it is perfectly understandable, though. I personally don’t just because of the RAM requirements compared to other OSs. Also GPU passthrough breaks things on my main gaming laptop.
They’re just basic Linux installs is what I mean. QubesOS isn’t much different than having a different computer running each piece of software on your LAN.
It’s a bit of an apples to oranges comparison, though. Desktop vs mobile. Hell, I’d hardly even compare Qubes to any Linux distro. It’s so niche and clunky to use as a daily driver. It’s basically just a hypervisor. A better comparison might be secureblue.
And a guest escaping is definitely not unheard of. https://www.techtimes.com/articles/319941/20260708/linux-kvm-guest-host-escape-hits-both-intel-amd-two-cves-required.htm
KVM guest escapes won’t affect Qubes, which doesn’t use it. Qubes is built on Xen instead - the Linux dom0 is itself a containerized management instance. That’s not to say that Xen container escape vulnerabilities are unheard of, but it’s a smaller attack surface and they are less common.