Re: [PATCH net v2 2/3] can: j1939: j1939_can_recv(): ignore messages with invalid source address

[Oleksij Rempel <o.rempel@pengutronix.de>]

On Thu, Oct 28, 2021 at 10:38:26PM +0800, Zhang Changzhong wrote:
> According to SAE-J1939-82 2015 (A.3.6 Row 2), a receiver should never
> send TP.CM_CTS to the global address, so we can add a check in
> j1939_can_recv() to drop messages with invalid source address.
> 
> Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
> Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>

Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>

> ---
>  net/can/j1939/main.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
> index 9bc55ec..461894e 100644
> --- a/net/can/j1939/main.c
> +++ b/net/can/j1939/main.c
> @@ -75,6 +75,12 @@ static void j1939_can_recv(struct sk_buff *iskb, void *data)
>  	skcb->addr.pgn = (cf->can_id >> 8) & J1939_PGN_MAX;
>  	/* set default message type */
>  	skcb->addr.type = J1939_TP;
> +	if (!j1939_address_is_valid(skcb->addr.sa)) {
> +		netdev_err_once(priv->ndev, "%s: sa is broadcast address, ignoring!\n",
> +				__func__);
> +		goto done;
> +	}
> +
>  	if (j1939_pgn_is_pdu1(skcb->addr.pgn)) {
>  		/* Type 1: with destination address */
>  		skcb->addr.da = skcb->addr.pgn;
> -- 
> 2.9.5
> 
> 

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