Messages in this thread | | | Date | Tue, 16 May 2017 19:48:21 +0100 | From | Al Viro <> | Subject | Re: [PATCH] [iov_iter] use memmove() when copying to/from user page |
| |
On Tue, May 16, 2017 at 02:27:34PM +0200, Alexander Potapenko wrote: > It's possible that calling sendfile() to copy the data from a memfd to > itself may result in doing a memcpy() with overlapping arguments. > To avoid undefined behavior here, replace memcpy() with memmove() and > rename memcpy_to_page()/memcpy_from_page() accordingly.
Er... And what semantics would you assign to such sendfile()? I really want to see details, because it sounds like memmove() here will not be any more useful than memcpy() - you still can esily get odd behaviour.
| |