2021-10-28 14:28:45

by Zhang Changzhong

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

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 <[email protected]>
---
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

2021-11-03 13:28:53

by Oleksij Rempel

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

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 <[email protected]>

Acked-by: Oleksij Rempel <[email protected]>

> ---
> 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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