This article explains troubleshooting scenarios where Gen 6 firewalls are rebooting due to "tsfTackLoc" found in the stack trace information from the tracelogs. This issue is observed in Gen 6 firewalls on firmware 18.104.22.168-26n.
This issue is caused by the Geo-IP and Botnet filter services on the firewall. The task refers to the Location Code which is common to both Geo-IP and Botnet Services.
The stack trace from the firewall looks similar to:
07/26/2016 19:12:16.048Reboot due to task suspension07/26/2016 19:12:16.048Task Trace tsfTaskLoc: