Hello, appreciate any help here. Objective: perform a scoped write to a removable block device (using low-level system frameworks in C). Issue: launchd-run privileged helper (as root) denied permission to open block device. Manual 'sudo ./helper' call succeeds, however. Importantly: the entire process works flawlessly if the main app is granted Full Disk Access in Privacy & Security. However, this should be completely unnecessary for this objective, as scoped access should be sufficient, and FDA is in fact not required for other apps which perform this task. Architecture and flow: Main GUI process collects ISO path and target removable device path (queried via IOKit). Main GUI process installs a Privileged Helper via SMJobBless. The Privileged Helper is started on demand by launchd as root (UID 0, EUID 0). Main GUI process communicates selected ISO and device paths to Privileged Helper via XPC. Privileged Helper conducts security and sanity checks, unmounts volumes from target device via DiskArbitration.
Topic:
App & System Services
SubTopic:
Core OS
Tags:
Background Tasks
Disk Arbitration
Files and Storage