After upgrade my build nodes from Ubuntu 20.04 to Ubuntu 22.04, I got a lot of spamming syslog messages on my Intel NUC nodes, model NUC5i5RYB. Both these nodes are running RKE2 v1.24.1+rke2r2. I have them tainted so that they are only used by Drone CI to run Kubernetes runners.

Error message

Jun 24 04:35:27 a0ubnucp02 kernel: [ 2025.557663] rc rc0: receive overflow
Jun 24 04:35:27 a0ubnucp02 kernel: [ 2025.561258] rc rc0: receive overflow
Jun 24 04:35:27 a0ubnucp02 kernel: [ 2025.566120] rc rc0: receive overflow
Jun 24 04:35:27 a0ubnucp02 kernel: [ 2025.569739] rc rc0: receive overflow
Jun 24 04:35:27 a0ubnucp02 kernel: [ 2025.618179] rc rc0: receive overflow
Jun 24 04:35:27 a0ubnucp02 kernel: [ 2025.637622] rc rc0: receive overflow
Jun 24 04:35:27 a0ubnucp02 kernel: [ 2025.645784] rc rc0: receive overflow
Jun 24 04:35:27 a0ubnucp02 kernel: [ 2025.649311] rc rc0: receive overflow
Jun 24 04:35:27 a0ubnucp02 kernel: [ 2025.656808] rc rc0: receive overflow
Jun 24 04:35:27 a0ubnucp02 kernel: [ 2025.660897] rc rc0: receive overflow

Fix

This error is cause by the built-in IR receiver on the Intel NUC. I didn’t even know that they had one. But because they are being used as Kubernetes nodes there is no need for this. So we are going to disable this module.

Temprary disable IR receiver

Run command: sudo modprobe -r ite_cir

You should see this message in the logs and the receive overflow messages should stop.

Jun 24 04:35:27 a0ubnucp02 kernel: [ 2025.728175] ite-cir 00:01: disabled

Note: This is a temporary fix and reboot will undo this change.

To make this permanent we need to blacklist this module by adding the following line to the /etc/modprobe.d/blacklist.conf file:

blacklist ite_cir

Then we need update initramfs to include the new blacklist. Run command: sudo update-initramfs -u

Note: A reboot is not required to make this change.