Use after free in `SupervisorResource`
Created by: ticki
Reproduction: Overwriting or dropping a supervised context (e.g., sys_exit) will not destroy the supervisor as well, making the supervisor hold a dangling ponter. This potentially allows a context to supervise a context, which isn't even a child.
Expected behavior: Drop or invalidate the supervisor resource when the context drops.
Although, this is fairly harmless currently, due to how contexts are stored, changes in the future can cause security vulnerabilities.
See kernel/fs/supervisor_resource.rs
.