Re: [PATCH 32/32] aio: implement io_pgetevents

[Al Viro]

On Tue, Jan 16, 2018 at 07:41:24PM -0500, Jeff Moyer wrote:
>       if (sigmask) {
> -             if (copy_from_user(&ksigmask, sigmask, sizeof(ksigmask)))
> +             if (!access_ok(VERIFY_READ, sigmask,
> +                            sizeof(void *) + sizeof(size_t)) ||
> +                 __get_user(up, (sigset_t __user * __user *)sigmask) ||
> +                 __get_user(sigsetsize,
> +                            (size_t __user *)(sigmask + sizeof(void *))))
>                       return -EFAULT;

How about copy_from_user() on a struct?  Making eyes bleed is fun, but
people tend to get annoyed when you do it to them...