Re: [PATCH v3 2/8] mm: userfaultfd: check for start + len overflow in validate_range

Peter Xu
2023-07-07T13:15:08Z

On Thu, Jul 06, 2023 at 03:50:30PM -0700, Axel Rasmussen wrote:
> Most userfaultfd ioctls take a `start + len` range as an argument.
> We have the validate_range helper to check that such ranges are valid.
> However, some (but not all!) ioctls *also* check that `start + len`
> doesn't wrap around (overflow).
>
> Just check for this in validate_range. This saves some repetitive code,
> and adds the check to some ioctls which weren't bothering to check for
> it before.
>
> Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>

Reviewed-by: Peter Xu <peterx@redhat.com>

--
Peter Xu