From: Dan Carpenter <dan.carpenter@oracle.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-fsdevel@vger.kernel.org
Subject: Re: [bug report] io_uring: add support for sqe links
Date: Mon, 27 May 2019 18:23:16 +0300 [thread overview]
Message-ID: <20190527152316.GJ24680@kadam> (raw)
In-Reply-To: <9b7b794b-26ed-7525-5f81-93cb60e1a005@kernel.dk>
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
prev parent reply other threads:[~2019-05-27 15:23 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-27 10:08 [bug report] io_uring: add support for sqe links Dan Carpenter
2019-05-27 13:36 ` Jens Axboe
2019-05-27 14:10 ` Dan Carpenter
2019-05-27 14:34 ` Jens Axboe
2019-05-27 15:23 ` Dan Carpenter [this message]
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