On Mon, May 27, 2019 at 08:34:18AM -0600, Jens Axboe wrote:
> On 5/27/19 8:10 AM, Dan Carpenter wrote:
> > On Mon, May 27, 2019 at 07:36:22AM -0600, Jens Axboe wrote:
> >> On 5/27/19 4:08 AM, Dan Carpenter wrote:
> >>> Hello Jens Axboe,
> >>>
> >>> The patch f3fafe4103bd: "io_uring: add support for sqe links" from
> >>> May 10, 2019, leads to the following static checker warning:
> >>>
> >>> fs/io_uring.c:623 io_req_link_next()
> >>> error: potential NULL dereference 'nxt'.
> >>>
> >>> fs/io_uring.c
> >>> 614 static void io_req_link_next(struct io_kiocb *req)
> >>> 615 {
> >>> 616 struct io_kiocb *nxt;
> >>> 617
> >>> 618 nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb, list);
> > ^^^^^^^^^^^^^^^
> > If this list is empty then "nxt" is NULL.
>
> Right...
>
> >>> 619 list_del(&nxt->list);
> >>> ^^^^^^^^^
> >>> The warning is a false positive but this is a NULL dereference.
> >>>
> >>> 620 if (!list_empty(&req->link_list)) {
> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> >
> > We're checking for list_empty() here.
>
> After deleting an entry from it.
>
Ah... Right. Sorry.
regards,
dan carpenter
