Re: Does uaccess_kernel() work for detecting kernel thread?

[Christoph Hellwig]

On Tue, Dec 22, 2020 at 11:33:58AM -0600, Eric W. Biederman wrote:
> I do wonder though if perhaps we should create a is_user_cred helper to
> detect the difference between the creds of kernel threads and the thread
> of ordinary userspace.   Which would handle io_uring that copy creds
> around and check them at a later time more cleanly.

I don't think we should as no one has a business to check this difference.
If there is a case where the creds are not correct for all access decisions
we need to fix that rather than adding hacks.