Message-ID: <daee2ba3-effc-67d6-71f7-e99797f93aeb@datenfreihafen.org>
Date:   Thu, 16 Mar 2023 17:31:59 +0100
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Subject: Re: [PATCH next] ca8210: Fix unsigned mac_len comparison with zero in
 ca8210_skb_tx()
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To:     Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Cc:     error27@gmail.com, Alexander Aring <alex.aring@gmail.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Marcel Holtmann <marcel@holtmann.org>,
        Harry Morris <harrymorris12@gmail.com>,
        linux-wpan@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230306191824.4115839-1-harshit.m.mogalapalli@oracle.com>
From:   Stefan Schmidt <stefan@datenfreihafen.org>
In-Reply-To: <20230306191824.4115839-1-harshit.m.mogalapalli@oracle.com>
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Precedence: bulk

Hello Harshit.

On 06.03.23 20:18, Harshit Mogalapalli wrote:
> mac_len is of type unsigned, which can never be less than zero.
> 
> 	mac_len = ieee802154_hdr_peek_addrs(skb, &header);
> 	if (mac_len < 0)
> 		return mac_len;
> 
> Change this to type int as ieee802154_hdr_peek_addrs() can return negative
> integers, this is found by static analysis with smatch.
> 
> Fixes: ded845a781a5 ("ieee802154: Add CA8210 IEEE 802.15.4 device driver")
> Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
> ---
> Only compile tested.
> ---
>   drivers/net/ieee802154/ca8210.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ieee802154/ca8210.c b/drivers/net/ieee802154/ca8210.c
> index 0b0c6c0764fe..d0b5129439ed 100644
> --- a/drivers/net/ieee802154/ca8210.c
> +++ b/drivers/net/ieee802154/ca8210.c
> @@ -1902,10 +1902,9 @@ static int ca8210_skb_tx(
>   	struct ca8210_priv  *priv
>   )
>   {
> -	int status;
>   	struct ieee802154_hdr header = { };
>   	struct secspec secspec;
> -	unsigned int mac_len;
> +	int mac_len, status;
>   
>   	dev_dbg(&priv->spi->dev, "%s called\n", __func__);
>   

This patch has been applied to the wpan tree and will be
part of the next pull request to net. Thanks!

I took the liberty and changed the fixes tag to the change that 
introduced the resaon for the mismatch recently. As suggested by Simon.

regards
Stefan Schmidt