Linux Agent Kernel: Not Connected (modprobe: ERROR: could not insert 'cbproxy_cbp)

Products

• Carbon Black App Control (formerly Cb Protection)

Issue/Introduction

• Agent is unable to connect to kernel.
• Issuing the command /opt/bit9/bin/b9cli --status returns:

  Kernel: Not Connected

• Issuing the command systemctl status b9daemon returns a similar error:

  b9daemon[1885]: modprobe: ERROR: could not insert 'cbproxy_cbp_VERSION': Required key not available
  b9daemon[1885]: insmod /lib/modules/3.10.0-1160.2.1.el7.x86_64/kernel/lib/cbproxy_cbp_VERSION.ko
  b9daemon[1885]: modprobe: ERROR: could not insert 'b9k_VERSION': Required key not available
  b9daemon[1885]: insmod /lib/modules/3.10.0-1160.2.1.el7.x86_64/kernel/lib/cbproxy_cbp_VERSION.ko
  

• Logs may include errors similar to:

  b9daemon[1885]: Checking b9k_87201 Driver
  b9daemon[1885]: Looking if modules directory is updated
  b9daemon[1885]: modprobe: ERROR: could not insert 'cbproxy_cbp_VERSION': Key was rejected by service

Environment

• App Control Linux Agent: 8.7.x and lower
• Linux OS: All Supported Versions

Cause

Secure Boot is enabled on the endpoint and the version of the Linux Agent installed does not support Secure Boot.

Resolution

Option 1: Disable UEFI Secure Boot:

1. Reboot the computer > Enter into the UEFI firmware / BIOS configuration.
2. Find the Secure Boot option (possibly under the security menu) and set it to disabled.
3. Save the change and reboot.

Option 2: Follow the instructions from the Agent Installation Guide to install Linux Agent version 8.8.0 or higher, which supports Secure Boot.

Additional Information

Using Secure Boot with the Linux Agent