In bug 1595715 comment 10 we saw that perhaps an external process is interfering with state files used by generic-worker. In order to reduce the risk that either a task or an external process is able to interfere with the files that generic-worker uses for persisting state between reboots, we should secure these files such that they can only be modified by the OS user that runs the generic-worker process.

We already do this for the generic-worker config file, the chain of trust signing key, and the current-task-user.json and next-task-user.json files but we should also do this for the other generic-worker state files:

• tasks-resolved-count.txt
  The record of how many tasks this worker has resolved
• file-caches.json
  The catalogue of all file caches on this worker
• directory-caches.json
  The catalogue of all directory caches on this worker

Released in generic-worker 16.5.6.