syslog.log kernel: [truncated] L/npch ==NULL/n

I noticed several threads that mention this system.log entry:

kernel: [truncated] L/npch ==NULL/npch ==NULL/n ... (usually repeats many times)

I see this with the OpenVpn server on the router with an active connection whenever data is accessed through the openvpn server by an openvpn client.

I also see it with idle vpn connections every 30-40 minutes (possibly due to vpn keepalives).

The place in the code where I see the printk() that produces this message is at...

syslog.log kernel: [truncated] L/npch ==NULL/n