Scenario in short:
I’m trying to install LineageOS onto a spare phone that I have. Hoping to get a daily driver out of it. The installation process requires me to install Android11 to install lineage on top of /over that. Which afaik isn’t directly available outside of some websites that I’ve never heard of.
For safety’s sake: would the install of lineage wipe the install of Android11? Or could there still remain backdoors?
Safe is relative but most liiely its wanting 11 because thats the version lineage you are using is based on.
As for these “some websites ive never heard of”… They might just be ai generated pages that hit on keywords common to android such as “root” and “custom rom”. Often they are scams that present instructions looking like they will work on phone models that dont have support for custom roms at all.
So be careful, make sure what you get comes from a decent source like android file host or xda, dont just go with random search results.
What device, specifically?
The bigger issues may be blobs used for radio firmware, but LineageOS should replace your OS. Assuming you can get regular updates and you aren’t the target of the state, you are probably fine.
This is why Lineage requires the factory OS first, to ensure certain drivers (eg modem) are in place.
Pretty sure we are on the same page here. My only concern is that the radio drivers would remain out of date because the manufacturer wouldn’t post updates and I don’t expect Lineage to handle an unexpected driver change gracefully.
I could be wrong and the drivers might be a trivial thing for lineage, but I doubt it.
Also, drivers, modules, firmware, I’m using these terms loosely because of the way they have been treated by Android, using Firmware to refer up Android itself.
Normally LineageOS replaces the version of Android previously installed on the phone.
I don’t know why the process asks for Android 11 as a starting point. There are a couple of valid reasons why you might need this, depending on the device.
Can you share a link to the process description?
At least in the case of my phone I had to put 11 back on to unlock the bootloader because OnePlus removed the ability to do it in their version of 12. Screw those guys.
AFAIK, custom ROMs ask for specific OS to get specific firmware for some peripherals (modem, WiFi, BT, etc).
E.g. installing Ubuntu Touch on Nord N10 5G requires a downgrade to OxygenOS 10 using the official tool, which (i believe) installs original firmwares.
Should mostly wipe the OS, so realistically safe. I think some firmware may remain, but overall should be clean.
Using an older OS is only a security issue if you actually do stuff with it. If you’re downgrading just to reinstall a newer OS then what malware is going to exploit your phone in that short period of time?
As others have said the real issue will probably be running old firmware for other things like your modem. But even then someone still has to be looking to explicitly exploit that.
Lineage doesn’t archive old versions of theur downloads, unfortunately.
The only risk I see is where you’re getting Lineage from. Are they a reputable source?
Even then, how likely is it that an old version of Lineage, for an out of production phone, is a target for malware? Possible, sure. Likely? Seems like a lot of effort for a very small surface.
