How does the new iOS inactivity reboot work? What does it protect from?

I reverse engineered the kernel extension and the secure enclave processor, where this feature is implemented.

https://naehrdine.blogspot.com/2024/11/reverse-engineering-ios-18-inactivity.html

@jiska so did you find anything about causing other devices on lower versions to reboot?

@mirabilos @jiska
This article (and a few others) mention this:

«In October of 2024, multiple users of iPhone 16 Pro and iPhone 16 Pro Max units reported that their devices kept restarting themselves for no apparent reason. This is a known issue that occurred during normal use and one that Apple fixed with the iOS 18.1 update.»
https://appleinsider.com/articles/24/11/07/iphones-stored-for-forensic-analysis-unexpectedly-reboot-causing-problems-for-officials

@jiska @marcel that does not answer my question. I specifically was wondering what became of this point:

2. iPhones on iOS 18 will tell other iPhones on lower iOS versions to reboot – wirelessly!

@mirabilos
I agree eith @jiska 's conclusion in the following paragraph that such a function would be stupid for Apple to implement (comparing it to a TV-Be-Gone for iPhones).

Also, there would be no clear benefit. Thieves/Police would then just put iPhones into separate wireless shielding bags to defeat the function.

So: Highly unlikely to have such a function. And spurious reboots are readily explained. And: Occam's Razor.

@marcel @jiska

that such a function would be stupid for Apple to implement

I saw that, but that was just speculation; I was looking for what came out of actually looking for it.

But noahm has pointed me to the result already.

@jiska „iPhones on iOS 18 will tell other iPhones on lower iOS versions to reboot – wirelessly!“ 🤯 I’m really curious about whether this is true and how it works. Definitely sounds crazy. I bet you‘re already looking into that as well.

@albrecht @jiska this is likely untrue; however, iPhones *can* now wirelessly receive a command to install a software update.

@albrecht There is a statement by @jiska in the article:
https://chaos.social/@noahm/113501035670541173
As well as some other thoughts, both elsewhere in this thread.
https://waldvogel.family/@marcel/113501030437323137

@abdelkader_boui @chucker @albrecht there have been some rumors about a feature allowing Apple to wirelessly update iPhones in original packaging. Maybe that's the reference?

However, the update process might only work after authentication and for sure requires a validly signed iOS software image. Also, that feature might be blocked after first setup.

@jiska Does this apply to iPad as well?

@WarrenGallagher haven't tried it myself but according to someone else in a chat, iPads on iPadOS 18.0 and newer also have inactivity reboot.

@jiska @abdelkader_boui @chucker @albrecht Updating phones in original packaging... How would that work? Legality versus shipping such packages using airplanes? Power management considerations?

@pavel @jiska @albrecht @abdelkader_boui

The basic idea is:

1) phones get shipped (air or vessel) to stores, which takes days or weeks
2) phones sit in store shelves, which can take further weeks
3) in the meantime, a newer iOS release is out
4) without removing the packaging, the phones are placed in a special device that sends a wireless signal for them to initiate a self-update
5) phones get placed back in shelves

And yes, power management is an issue.

@chucker @jiska @albrecht @abdelkader_boui Is there any writeup how this works? Having phone check for updates for weeks on one battery change is not easy.

@pavel @jiska @albrecht @abdelkader_boui

https://norden.social/@chucker/113505991650017887

And keep in mind the phones aren’t (yet) booted, so their battery use is minimal. The signal supposedly tells them to boot, update, and shut down again.

Thank you for all the questions on iOS inactivity reboot!

I added answers to the most common questions at the end of my blog post.

@jiska wen eta?

@saagar son