On Fri, Aug 28, 2020 at 02:13:43PM +0000, albert.linde@xxxxxxxxx wrote: > @@ -82,6 +83,8 @@ __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) > static __always_inline __must_check unsigned long > __copy_from_user(void *to, const void __user *from, unsigned long n) > { > + if (should_fail_usercopy()) > + return n; > might_fault(); > instrument_copy_from_user(to, from, n); > check_object_size(to, n, false); > @@ -124,7 +131,7 @@ _copy_from_user(void *to, const void __user *from, unsigned long n) > { > unsigned long res = n; > might_fault(); > - if (likely(access_ok(from, n))) { > + if (!should_fail_usercopy() && likely(access_ok(from, n))) { > instrument_copy_from_user(to, from, n); > res = raw_copy_from_user(to, from, n); > } You're inconsistent with your order against might_fault() throughout the patch. After is the right place.