cPhulkd causing soft lockup

[dstana]

cPhulkd seems to be the culprit in an issue that's locking up the server. From our logs:

kernel: NMI watchdog: BUG: soft lockup - CPU#5 stuck for 22s! [cPhulkd - proce:4599]

After a reboot, it's back again:

kernel: NMI watchdog: BUG: soft lockup - CPU#4 stuck for 22s! [cPhulkd - proce:5572]

Server is running WHM version 70.0.46 with Centos 7.5.1804 (Kernel 3.10.0-862.3.2.el7.x86_64). I've added just a single line of each of the errors, but they go and go until the server is rebooted before starting again.

 

[cPanelMichael]

Hello @dstana,

Can you let us know the OS, kernel, and cPanel versions installed on the affected system? EX:

cat /etc/redhat-release
uname -r
cat /usr/local/cpanel/version

Thank you.

 

[dstana]

I edited my post to include that.

 

[cPanelMichael]

Hello @dstana,

I don't see anything suggesting this relates to a bug with cPanel & WHM or the cPHulk Brute Force Protection feature. Could you open a support ticket so we can take a closer look at the affected system and rule out any issues with cPanel & WHM?

Thank you.

 

[dstana]

Ticket opened.

 

[cPanelMichael]

Hello,

To update, it looks like this was the result of a DDOS attack on the server. The advice in the support ticket was to reach out to the hosting provider or data center to see if it can be mitigated from the network level.

Thank you.