nut: has insufficient permissions to access USB UPS #28579
Description
Package Name
nut
Maintainer
@hnyman @s-hamann @tofurky @BKPepe @systemcrash
OpenWrt Version
SNAPSHOT r33075-20644af030
OpenWrt Target/Subtarget
bcm27xx/bcm2709
Steps to Reproduce
- Add a UPS configuration to
nut_serverfor a USB UPS - Restart the server
/etc/init.d/nut_server restart
Actual Behaviour
In the logs the following message appears:
Fri Feb 13 23:39:01 2026 daemon.debug upsd[3504]: [D1] mainloop: UPS [eco550ups] is not currently connected, trying to reconnect
Fri Feb 13 23:39:01 2026 daemon.debug upsd[3504]: [D1] mainloop: UPS [eco550ups] is still not connected (FD -1)
Fri Feb 13 23:39:03 2026 daemon.debug upsd[3504]: [D1] mainloop: UPS [eco550ups] is not currently connected, trying to reconnect
Fri Feb 13 23:39:03 2026 daemon.debug upsd[3504]: [D1] mainloop: UPS [eco550ups] is still not connected (FD -1)
unplugging the UPS and plugging it back in resolves the issue, as does restarting the system.
In PR #28382 it was observed that the same procedure would result in the following messages:
Fri Feb 13 23:38:44 2026 daemon.err usbhid-ups[3083]: No matching HID UPS found
Fri Feb 13 23:38:49 2026 daemon.warn procd: failed adding instance cgroup for nut-server: No error information
Fri Feb 13 23:38:49 2026 daemon.err usbhid-ups[3115]: libusb1: Could not open any HID devices: insufficient permissions on everything
Fri Feb 13 23:38:49 2026 daemon.err usbhid-ups[3115]: No matching HID UPS found
Fri Feb 13 23:38:54 2026 daemon.warn procd: failed adding instance cgroup for nut-server: No error information
Which is more helpful. It tells us the issue is with the permissions on the USB device in /dev. The workarounds work because they trigger the hotplug script, which updates the permissions.
Proposed solution is to have a newly configured driver trigger the hotplug script, at least where USB product Id and USB vendor Id are configured.
Confirmation Checklist
- The package is maintained in this repository.
- I understand that issues related to the base OpenWrt repository or LuCI repository will be closed.
- I am reporting an issue for OpenWrt, not an unsupported fork.