On 10/31/17 1:41 AM, Jiri Pirko wrote:

quoted

If it is read-only, then attempts to set it from userspace should cause
the command to fail.

That breaks uapi. Consider existing userspace app sending garbage in
that bit and new kernel which randomly fails upon the garbage.

It is called syzkaller. The kernel should always validate userspace
config including checking that unused bits are 0. So you are saying tc
has never done that checking and just ignored bits that are not valid?