Profile Secuirty Do They Work Like Seperate Virtual Machines?

PrivacyEndGame

I'm wondering if creating a profile for more insecure dangerous activities like untrustworthy downloads or visiting more dangerous websites in a dedicated profile will provide me more security then doing these activities in my main non owner profile. Or would creating a new profile for more security risky activities just be providing me a false sense of security or is there a legitimate benefit to doing this approach?

pxlkng

PrivacyEndGame

Profiles do not aid the app sandbox nor increase the security of it. They also do not increase the confinement or privacy of apps apart from blocking IPC and package discovery across profiles.
The app sandbox is the same everywhere, also in Owner, so no profile is more dangerous or more safe to run apps in. You can run everything in Owner or run everything in its own profile. In an overall security and privacy sense of the app sandbox this is the same.

Profiles are also not virtualized.

de0u

PrivacyEndGame User profiles isolate apps in terms of inter-process communication (IPC). But if an app is truly dangerous then in theory it could break out of the app sandbox.

It would be best to avoid downloading materials from untrustworthy sources, or to use a separate device.

TheGodfather

PrivacyEndGame it's not the same. VMs don't share the OS and especially don't share the kernel.

pxlkng

Profiles are recommended to be used based on personas, like personal/work/school, not based on app or usage categories as there isn't any tangible benefit in separating them like this, unless you want to specifically make use of profile features like individual encryption and the ability to put them at rest, for example.

Profiles are not a necessity for a secure and private setup. If you have just one persona and no specific reason to use profiles (like for using their features as mentioned above) the recommendation is to just use Owner and install everything (also Play Services if needed) there. Otherwise you're likely just going to increase friction and decrease user experience by unnecessarily using profiles, with no real privacy or security benefit.

chinook

de0u apps can talk over localhost (this is how Inter Profile Sharing is working). It doesn't even need to try to break out, it can just babble¹ :)

¹ Rethink should be able to block these.

gvprtskvni

chinook ¹ Rethink should be able to block these.

Could you elaborate on this? (I don't need any inter-profile sharing and would like to disable it if possible.)

chinook

RethinkDNS blocking covert localhost communication

I didn't have to do it but hey, someone should find it out first, try :)

I tried to Configure > Apps > Inter Profile Sharing > Isolate, and then added 127.0.0.0/8 to blocked
Then I enabled Configure > Network > Loopback proxy forwarded apps, but it's apparently not that.

That didn't stop it from being able to share files between profiles; I also can't see anything in the logs, but don't have time to investigate it further. Would probably have to whitelist access to DNS anyways, maybe more.

Maybe ignoramus will show up and advise (not @ intentionally :) )

ignoramous

chinook tried to Configure > Apps > Inter Profile Sharing > Isolate, and then added 127.0.0.0/8 to blocked

Yep, Loopback traffic isn't routed to VPN tunnel on Android. See also: https://discuss.grapheneos.org/d/22889-meta-and-yandex-are-de-anonymizing-android-users-web-browsing-identifiers/29

ignoramous

TheGodfather VMs don't share the OS and especially don't share the kernel.

Depends as Kernels (Supervisors) like Linux also double up as Hypervisor. Though, you're right in that Hypervisor isn't executing the same code as Supervisor, but incorrect to assume that they are always separate.

On Android, I must note, the pKVM is a much improved design (for "confidential computing", if nothing else) because the Hypervisor is separate from the Supervisors (even if bundled in the same Kernel artifact) than the usual KVM-based approaches we see in other Linux distros.

chinook

ignoramous thank you, this is a very valuable piece of information.