USER MODE TASKS CAN MODIFY PRIVILEGED TASKS

```
Description: Certain interfaces, such as sched_setparam(),
sched_setscheduler(), etc. can be used by user mode tasks to
modify the behavior of privileged kernel threads.
For a truly secure system. Privileges need to be checked in
every interface that permits one thread to modify the
properties of another thread.

NOTE: It would be a simple matter to simply disable user
threads from modifying privileged threads. However, you
might also want to be able to modify privileged threads from
user tasks with certain permissions. Permissions is a much
more complex issue.

task_delete(), for example, is not permitted to kill a kernel
thread. But should not a privileged user task be able to do
so?
Status: Open
Priority: Low for most embedded systems but would be a critical need if
NuttX were used in a secure system.
```