Pingfan Liu <kernelf...@gmail.com> writes: > As for FOLL_LONGTERM, it is checked in the slow path > __gup_longterm_unlocked(). But it is not checked in the fast path, which > means a possible leak of CMA page to longterm pinned requirement through > this crack.
Shouldn't we disallow FOLL_LONGTERM with get_user_pages fastpath? W.r.t dax check we need vma to ensure whether a long term pin is allowed or not. If FOLL_LONGTERM is specified we should fallback to slow path. -aneesh
