On Thu, Apr 01, 2021 at 09:05:22AM -0700, Linus Torvalds wrote: > On Wed, Mar 31, 2021 at 11:51 PM Omar Sandoval <osandov@xxxxxxxxxxx> wrote: > > > > + * > > + * The recommended usage is something like the following: > > + * > > + * if (usize > PAGE_SIZE) > > + * return -E2BIG; > > Maybe this should be more than a recommendation, and just be inside > copy_struct_from_iter(), because otherwise the "check_zeroed_user()" > call might be quite the timesink for somebody who does something > stupid. I did actually almost send this out with the check in copy_struct_from_iter(), but decided not to for consistency with copy_struct_from_user(). openat2() seems to be the only user of copy_struct_from_user() that doesn't limit to PAGE_SIZE, which is odd given that Aleksa wrote both openat2() and copy_struct_from_user(). Aleksa, was this intentional? Thanks, Omar
