search

kpwn / yalu102

incomplete iOS 10.2 jailbreak for 64 bit devices by qwertyoruiopz and marcograssi
Do What The F*ck You Want To Public License
1.77k stars 554 forks source link

iPhone 6: Consistent Kernel Hang/Reboot with UIImage/CoreGraphics API/Floating Point usage #478

Open coolstar opened 7 years ago

coolstar commented 7 years ago

Device tested: iPhone 6

Steps to trigger bug (possible to trigger via other methods too [such as usage of the device's Camera], but this is the easiest):

  1. Install 20-30 apps if you don't have many apps on the device
  2. Install Anemone, any icon theme, and CircleIcons (from https://coolstar.org/publicrepo)
  3. Enable the icon theme and CircleIcons in Anemone
  4. Open Settings > General > Storage & iCloud Usage > Manage Storage (under Storage)
  5. Scroll down the list

Observed behavior: the device either freezes (and is then completely unresponsive over the network, or even over USB [plugging it into a computer doesn't enumerate the device]) or instantly reboots with a kernel panic about 60% of the time

Expected behavior (tested on iPhone 6S with yalu10.2 and on iPad Air 2 with Pangu9.3.3): The usage panel loads correctly and the device is completely functional and responsive

API's used in Anemone:

  1. MSHookMessage (hooking +[UIImage _applicationIconImageForBundleIdentifier: format: scale:])
  2. UIGraphicsBeginImageContextWithOptions
  3. -[UIImage drawInRect:]
  4. UIGraphicsGetImageFromCurrentImageContext
  5. UIGraphicsEndImageContext

If needed, I can provide a test tweak with just the portion that causes this issue in yalu10.2

Reddit post: https://www.reddit.com/r/jailbreak/comments/6dc1zj/discussion_stability_or_lack_of_yalu102/