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

[Jiale Yao <yaojiale02@163.com>]

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").

Link: https://lore.kernel.org/all/b58d98e0-8fe3-4e4e-b8a5-c1c7e647ccca@hartkopp.net/
Fixes: 1d76efe1577b ("team: add support for non-ethernet devices")
Assisted-by: Claude:deepseek-v4-pro
Signed-off-by: Jiale Yao <yaojiale02@163.com>
---
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