Date:   Tue, 23 Nov 2021 11:11:51 +0200
From:   Leon Romanovsky <leon@kernel.org>
To:     =?iso-8859-1?Q?H=E5kon?= Bugge <haakon.bugge@oracle.com>
Cc:     Doug Ledford <dledford@redhat.com>, Jason Gunthorpe <jgg@ziepe.ca>,
        linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH for-rc] RDMA/cma: Remove open coding for overflow in
 cma_connect_ib
Message-ID: <YZywV4lRV7g4Bj87@unreal>
References: <1637599733-11096-1-git-send-email-haakon.bugge@oracle.com>
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On Mon, Nov 22, 2021 at 05:48:53PM +0100, H?kon Bugge wrote:
> The existing test is a little hard to comprehend. Use
> check_add_overflow() instead.
> 
> Fixes: 04ded1672402 ("RDMA/cma: Verify private data length")
> Signed-off-by: H?kon Bugge <haakon.bugge@oracle.com>
> ---
>  drivers/infiniband/core/cma.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
> index 835ac54..0435768 100644
> --- a/drivers/infiniband/core/cma.c
> +++ b/drivers/infiniband/core/cma.c
> @@ -4093,8 +4093,7 @@ static int cma_connect_ib(struct rdma_id_private *id_priv,
>  
>  	memset(&req, 0, sizeof req);
>  	offset = cma_user_data_offset(id_priv);
> -	req.private_data_len = offset + conn_param->private_data_len;
> -	if (req.private_data_len < conn_param->private_data_len)
> +	if (check_add_overflow(offset, conn_param->private_data_len, &req.private_data_len))
>  		return -EINVAL;

The same check exists in cma_resolve_ib_udp too.

Thanks

>  
>  	if (req.private_data_len) {
> -- 
> 1.8.3.1
>