On Thu, Nov 08, 2018 at 03:36:10PM +0100, Andrey Konovalov wrote: > copy_from_user (and a few other similar functions) are used to copy data > from user memory into the kernel memory or vice versa. Since a user can > provided a tagged pointer to one of the syscalls that use copy_from_user, > we need to correctly handle such pointers. > > Do this by untagging user pointers in access_ok and in __uaccess_mask_ptr, > before performing access validity checks. > > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>