Backporting an old kernel should be possible, but the only indicator is the system update changelog that explicitly mentions it, I rarely see CVEs mentioned in changelogs on any smartphone. A tool to test the vulnerability is the only way.
Any compromised app on the Play store or external can get root access instantly, but we can still rely on trust and audits when installing apps which should always be the rule.
I suspect that this will be added to all Google Play integrity levels, limiting many apps from being installed on unpatched phones in the future.
That's not the case with browsers with random sites and ads which is hardly avoidable, having any sandbox escape is now more severe considering that it bypasses the app container. It's similar to JailbreakMe on iOS [0]
How the cluster f*k of the Android update situation Google has allowed this to happen really needs a regulator to step in.
Planned obsolescence is supposed to be illegal in Europe.
The alternative would be for the hardware market to be less consolidated (the government keeps allowing Qualcomm to buy up competitors) so that the chip companies would have to compete on things like this. But that's no excuse for Google to be sitting on their hands when they could fix it too.
Just like Microsoft with Windows.
You do realize that a full kernel vulnerability like this allows you to feed falsified information to SafetyNet? Just like DRM, it gives the developer the illusion of control, but doesn't do anything to actually improve "safety" or "integrity".
It's silly that whenever I see a vulnerability like this, all I can think about is "finally, a way to get control over my own devices back". Once again, Stallman was right.
https://www.gnu.org/philosophy/right-to-read.en.html
Personally, I'll use this to root my Android TV and Chromecast devices and remove the shitty ads in the launcher (which Google added after I bought the devices!).
Good news for reusing old phones and taking control.
*as in replace
The proper solution is one we had with desktop computing for decades. If you keep the key material on your eID or bank card, you don't need a locked down operating system. Which then allows devices to live for much longer.
We're slowly losing the war on General Purpose Computing.
https://media.ccc.de/v/28c3-4848-en-the_coming_war_on_genera...
So you want a bank card/ID card to be required each time you use Google Pay? What's the point of Google Pay then.
Maybe I could even duct-tape it to my phone if I really want to do that.
From then your Google Pay account is authorized to initiate charges until you tell your bank otherwise and you don't need the card again unless you want to sign up for Venmo etc.
And it makes things easy if someone steals your phone, because you just sign into the payment processor and deauthorize the device or, if they've already changed your password etc., sign into (or go to) the bank and deauthorize the payment processor.
That then allows you to do secure NFC credit card payments even on a rooted phone with custom ROM.
Not a great solution.
Which hasn't been an issue since Chip & PIN became required, 22 years ago (at least over here).
The problem being that there are many millions of people who can't afford to replace a phone they only recently bought just because the vendor never updates it, which means those banks and things can't in practice demand that people do that. Indeed, it creates the opposite problem, because installing a custom ROM on that device would give it a patched kernel but cause it to fail attestation, so what the attestation is actually doing is requiring those people to continue to use the vulnerable OS.
A lot of phones don't receive any upgrades after 1 or 2 years...
I wish that Google would have forced vendors to implement a proper hardware abstraction (uefi or similar) so that a single kernel could run on any smartphone, just like it's the case for PCs...
https://source.android.com/docs/core/architecture/kernel/gen...
Are you sure that's true? The whole reason why modern Safetynet/Play Integrity uses HSM data where possible is that you can't spoof that with root (without a microcode bug). It does not trust the running OS by design
I just tried GrapheneOS's https://attestation.app/ on a stock Pixel, and all of the OS version info shows in the "hardware verified" section
First there is Android's attestation framework. That does actual hardware attestation, as used by GrapheneOS, and supported by literally no app whatsoever.
Then there is SafetyNet, now Play Integrity. Depending on what level of integrity checking is being done, this will do a combination of cursory surface-level software checks, delegation to the aforementioned hardware attestation framework, and several other checks.
Importantly, SafetyNet/Play Integrity rejects some devices that pass hardware attestation (e.g., Graphene OS), and accepts some devices that fail hardware attestation (fairphone, many cheaper devices with broken ROMs, etc).
e.g., fairphone leaked the private key for their attestation, but many of their devices still pass SafetyNet, while some other devices that pass attestation but have known bootloader flaws are blocked by SafetyNet.
Because this isn't strict cryptographic verification, but a mess of heuristics and guesswork, it's a constant cat and mouse game.
What Google really achieved here is to make it expensive enough that no casual user can bypass it to e.g. cheat in Pokemon Go, but only a determined attacker has a chance.
And with "determined attacker" I'm not just talking about states, but even e.g. movie pirates breaking DRM to rip Netflix movies.
Of course, even full cryptographic attestation isn't perfect, and can be bypassed with enough effort. As shown by the famous iPhone hardware jailbreak, where you drill into the SoC and solder directly to the CPU's internal wiring.
Any app that can run native code execution on any version of Linux in the past fifteen years can get root until kernel updates arrive on your devices.