jiska 🦄Nov 8, 2024

Apple added a feature called "inactivity reboot" in iOS 18.1. This is implemented in keybagd and the AppleSEPKeyStore kernel extension. It seems to have nothing to do with phone/wireless network state. Keystore is used when unlocking the device. So if you don't unlock your iPhone for a while... it will reboot!

In the news: "Police Freak Out at iPhones Mysteriously Rebooting Themselves, Locking Cops Out"
https://www.404media.co/police-freak-out-at-iphones-mysteriously-rebooting-themselves-locking-cops-out/

iOS version diffs to see yourself:
https://github.com/search?q=repo%3Ablacktop%2Fipsw-diffs%20inactivity_reboot&type=code

Police Freak Out at iPhones Mysteriously Rebooting Themselves, Locking Cops Out

Law enforcement believe the activity, which makes it harder to then unlock the phones, may be due to a potential update in iOS 18 which tells nearby iPhones to reboot if they have not been in contact with a cellular network for some time, according to a document obtained by 404 Media.

404 Media
Show threadRick BaumhauerNov 8, 2024
@jiska @cstross Is this also in iPadOS? I have mine on a stand next to my Mac’s monitor (which it is also connected to via a USB hub), but it is my least-used device, and it mysteriously rebooted itself last night.
Show threadAlexia  Nov 8, 2024

@rick_baumhauer for all intensive purposes iPadOS is a different branch of iOS and as this is not a platform-specific feature to my knowledge I very much expect this to exist on iPadOS too

I may check the IPSW diffs of an iPad and reply later if I find the time, but in no way should you consider me an expert on this 

Show threadRick BaumhauerNov 8, 2024
@cyrus Thanks! It’s my assumption that it is part of iPadOS, but since this was the first I’d heard of this “inactivity reboot”, I wanted to get confirmation (within reason - I don’t expect anyone to spend their day digging through this) before I chalked up my mystery reboot last night to it. It does make sense, though - I’m sure I hadn’t done much with my iPad in a few days.
Show threadAlexia  
@rick_baumhauer fwiw, this functionality is new, iOS (seemingly?) could force you to put in your PIN before but that is less powerful than never having entered it after a reboot - as at that point the key to data on the device has not yet been entered by the user and as such cannot be extracted from anywhere on the device
Nov 8, 2024 at 8:43pmWeb