Re: [PATCH v6 3/7] fs: Add receive_fd() wrapper for __receive_fd()

[Christoph Hellwig]

On Mon, Jul 06, 2020 at 01:17:16PM -0700, Kees Cook wrote:
> For both pidfd and seccomp, the __user pointer is not used. Update
> __receive_fd() to make writing to ufd optional via a NULL check. However,
> for the receive_fd_user() wrapper, ufd is NULL checked so an -EFAULT
> can be returned to avoid changing the SCM_RIGHTS interface behavior. Add
> new wrapper receive_fd() for pidfd and seccomp that does not use the ufd
> argument. For the new helper, the allocated fd needs to be returned on
> success. Update the existing callers to handle it.

Oh here we go, I'll take the last comment back.