From: Tobias Holl tobias@tholl.xyz
commit 776617db78c6d208780e7c69d4d68d1fa82913de upstream.
Pages that are from the same folio do not necessarily need to be consecutive. In that case, we cannot consolidate them into a single bvec entry. Before applying the huge page optimization from commit 57bebf807e2a ("io_uring/rsrc: optimise registered huge pages"), check that the memory is actually consecutive.
Cc: stable@vger.kernel.org Fixes: 57bebf807e2a ("io_uring/rsrc: optimise registered huge pages") Signed-off-by: Tobias Holl tobias@tholl.xyz [axboe: formatting] Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- io_uring/rsrc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/io_uring/rsrc.c +++ b/io_uring/rsrc.c @@ -1230,7 +1230,12 @@ static int io_sqe_buffer_register(struct if (nr_pages > 1) { folio = page_folio(pages[0]); for (i = 1; i < nr_pages; i++) { - if (page_folio(pages[i]) != folio) { + /* + * Pages must be consecutive and on the same folio for + * this to work + */ + if (page_folio(pages[i]) != folio || + pages[i] != pages[i - 1] + 1) { folio = NULL; break; }