This continues the thread
I’ll assume that you still haven’t noticed any DNS problems (just such logs).
I found some instance of the lines in my log archive, and my understanding is that they happened when the LAN was down temporarily. Some requests arrived when it was OK but now the replies could not be sent and (perhaps surprisingly) kernel marked that with “Permission denied”.
Network device 'eth2' link is down
It’s perhaps weird that that it’s “Permission denied”, but disabling IPv6 also causes that message. I’m not sure why the errors get classified this way (on Turris OS).