On Wed, Jul 13, 2022 at 1:13 AM Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> wrote: > > untagged_addr() is a helper used by the core-mm to strip tag bits and > get the address to the canonical shape. In only handles userspace > addresses. The untagging mask is stored in mmu_context and will be set > on enabling LAM for the process. > > The tags must not be included into check whether it's okay to access the > userspace address. > > Strip tags in access_ok(). > > get_user() and put_user() don't use access_ok(), but check access > against TASK_SIZE directly in assembly. Strip tags, before calling into > the assembly helper. > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Tested-by: Alexander Potapenko <glider@xxxxxxxxxx>
