Not sure I understand description of this bug. System is not running during the update, entire update of system image is done in recovery mode, when phone boots from recovery ramdisk and mounts system partition in writable mode, but does not execute anything from that partition. Same goes for kernel and initrd, it's not executed in any way during update.
Can you specify what do you mean by "That would lead to DoS since no user can login within that window." Since Ubuntu running at all, user is able to log or connect to the phone during entire process anyway.
Not sure I understand description of this bug. System is not running during the update, entire update of system image is done in recovery mode, when phone boots from recovery ramdisk and mounts system partition in writable mode, but does not execute anything from that partition. Same goes for kernel and initrd, it's not executed in any way during update.
Can you specify what do you mean by "That would lead to DoS since no user can login within that window." Since Ubuntu running at all, user is able to log or connect to the phone during entire process anyway.