Re: [PATCH v2] team: reject CAN and IEEE 802.15.4 devices in team_port_add

[Jiri Pirko]

Tue, Jul 28, 2026 at 05:12:40PM +0200, yaojiale02@xxxxxxx wrote:
>Enslaving a CAN or IEEE 802.15.4 device (e.g. vxcan, wpan0) to a
>team master triggers a NULL pointer dereference because these
>device types use different Layer 2 architectures from Ethernet and
>the team driver never initializes their private mid-layer data
>structures.
>
>Reject ARPHRD_CAN, ARPHRD_IEEE802154, and ARPHRD_IEEE802154_MONITOR
>devices in team_port_add(), mirroring the existing CAN check already
>present in the bonding driver since commit 8ba68464e478 ("bonding:
>refuse to enslave CAN devices").

Can we perhaps have a unified helper for the check?


>
>Link: https://lore.kernel.org/all/b58d98e0-8fe3-4e4e-b8a5-c1c7e647ccca@xxxxxxxxxxxx/
>Fixes: 1d76efe1577b ("team: add support for non-ethernet devices")
>Assisted-by: Claude:deepseek-v4-pro

Looks your ai gone a bit wild here...


>Signed-off-by: Jiale Yao <yaojiale02@xxxxxxx>
>---
>V1 -> V2: Extended check to also reject ARPHRD_IEEE802154 and
>  ARPHRD_IEEE802154_MONITOR devices per review feedback
>---
> drivers/net/team/team_core.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
>diff --git a/drivers/net/team/team_core.c b/drivers/net/team/team_core.c
>index feaa75fbf8fc..d8c46105fc8b 100644
>--- a/drivers/net/team/team_core.c
>+++ b/drivers/net/team/team_core.c
>@@ -1224,6 +1224,17 @@ static int team_port_add(struct team *team, struct net_device *port_dev,
> 		return -EINVAL;
> 	}
> 
>+		if (port_dev->type == ARPHRD_CAN ||
>+		    port_dev->type == ARPHRD_IEEE802154 ||
>+		    port_dev->type == ARPHRD_IEEE802154_MONITOR) {
>+			NL_SET_ERR_MSG(extack,
>+				       "CAN and IEEE 802.15.4 devices can't be added as a team port");
>+			netdev_err(dev, "Device %s is CAN or IEEE 802.15.4. These device types can't be added as a team port\n",
>+				   portname);
>+			return -EINVAL;
>+		}
>+	}
>+
> 	if (netif_is_team_port(port_dev)) {
> 		NL_SET_ERR_MSG(extack, "Device is already a port of a team device");
> 		netdev_err(dev, "Device %s is already a port "
>-- 
>2.34.1
>