We can only deal with FOLL_WRITE and/or FOLL_LONGTERM in get_user_pages_fast, so reject all other flags. Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- mm/gup.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/gup.c b/mm/gup.c index 0e83dba98dfd..37a2083b1ed8 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2317,6 +2317,9 @@ int get_user_pages_fast(unsigned long start, int nr_pages, unsigned long addr, len, end; int nr = 0, ret = 0; + if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM))) + return -EINVAL; + start = untagged_addr(start) & PAGE_MASK; addr = start; len = (unsigned long) nr_pages << PAGE_SHIFT; -- 2.20.1
