App Control: Systems Freezing due to Conflict With 'parity.sys' and Crowdstrike

Products

• Carbon Black App Control (formerly Cb Protection)

Issue/Introduction

• Windows systems freeze and hang intermittently
• The CrowdStrike 'csagent' worker threads appear to be blocked by 'parity.sys'

Environment

• App Control Agent: All Versions
• Windows Servers w/ CrowdStrike installed

Cause

Crowdstrike has confirmed issue is related to a new feature in their software that provides an extra level of protection to systems with newer hardware.

Resolution

Crowdstrike has identified this issue and is working on a fix. 

Additional Information

From VMware Engineering Team: 

Basically, CrowdStrike queues up a special Asynchronous Procedure Call (APC) which fires before the Agent can unlock our push lock. The CrowdStrike APC ends up calling the Agent, the Agent then tries to acquire the push lock shared. This would normally work except that another thread is waiting on exclusive access, which causes the deadlock.