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Date: Sat, 23 Dec 2023 07:56:49 -0700
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Subject: Re: KMSAN: uninit-value in io_rw_fail
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To: xingwei lee <xrivendell7@gmail.com>
Cc: syzbot+12dde80bf174ac8ae285@syzkaller.appspotmail.com,
 asml.silence@gmail.com, io-uring@vger.kernel.org,
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From: Jens Axboe <axboe@kernel.dk>
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On 12/23/23 2:07 AM, xingwei lee wrote:
> with the patch that you provided make a little change to apply to this
> commit: 5254c0cbc92d2a08e75443bdb914f1c4839cdf5a
> 
> diff --git a/io_uring/rw.c b/io_uring/rw.c
> index 4943d683508b..0c856726b15d 100644
> --- a/io_uring/rw.c
> +++ b/io_uring/rw.c
> @@ -589,15 +589,19 @@ static inline int io_rw_prep_async(struct
> io_kiocb *req, int rw)
>       struct iovec *iov;
>       int ret;
> 
> +       iorw->bytes_done = 0;
> +       iorw->free_iovec = NULL;
> +
>       /* submission path, ->uring_lock should already be taken */
>       ret = io_import_iovec(rw, req, &iov, &iorw->s, 0);
>       if (unlikely(ret < 0))
>               return ret;
> 
> -       iorw->bytes_done = 0;
> -       iorw->free_iovec = iov;
> -       if (iov)
> +       if (iov) {
> +               iorw->free_iovec = iov;
>               req->flags |= REQ_F_NEED_CLEANUP;
> +       }
> +
>       return 0;
> }
> 
> since the reproducer is in a loop
> and I ran for about 30 minutes it didn't trigger any issues.
> 
> I hope it helps.

Yep, thanks for testing!

-- 
Jens Axboe