- When cancelling ioctls, VFS did not remember which file descriptor
to cancel and sent bogus to the driver.
- Select state was not cleaned up when select()ing process was
interrupted.
- Process trying to do a system call at the exact same time as a user
trying to interrupt the process, could cause the system call worker
thread to overwrite state belonging to the worker thread trying to
exit the process. This led to hanging threads and eventual system hang
when this happens often enough.