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

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