Re: [PATCH] bonding: reject IEEE 802.15.4 devices in bond_enslave

[Eric Dumazet]

On Mon, Aug 31, 2026 at 4:07 PM Jiale Yao <yaojiale02@xxxxxxx> wrote:
>
> Bonding already refuses CAN devices because their protocol-specific state
> is incompatible with the bonding model. IEEE 802.15.4 devices have the
> same constraint: they keep protocol-specific state in
> dev->ieee802154_ptr and do not use Ethernet link-layer semantics.
>
> Extend the existing check to reject ARPHRD_IEEE802154 and
> ARPHRD_IEEE802154_MONITOR devices before bonding changes their link-layer
> settings.
>
> Link: https://lore.kernel.org/netdev/aohMHTTH4VqqgZA7@fedora/
> Link: https://lore.kernel.org/netdev/6001bd73-ef68-4820-8371-a22775fb820a@xxxxxxxxxxxx/
> Fixes: d5ae67bacd96 ("ieee802154: rework interface registration")
> Suggested-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
> Signed-off-by: Jiale Yao <yaojiale02@xxxxxxx>
> ---
>  drivers/net/bonding/bond_main.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 522eab060f9e..c716336c5172 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -1894,9 +1894,11 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
>         struct sockaddr_storage ss;
>         int res = 0, i;
>
> -       if (slave_dev->type == ARPHRD_CAN) {
> +       if (slave_dev->type == ARPHRD_CAN ||
> +           slave_dev->type == ARPHRD_IEEE802154 ||
> +           slave_dev->type == ARPHRD_IEEE802154_MONITOR) {
>                 BOND_NL_ERR(bond_dev, extack,
> -                           "CAN devices cannot be enslaved");
> +                           "CAN and IEEE 802.15.4 devices cannot be enslaved");
>                 return -EPERM;
>         }

What about ARPHRD_6LOWPAN ?

I think it is due time to use an allowlist in bonding (and team) to
stop applying bandaids.

Plan of action:

1) Add:

static inline bool netdev_type_is_lag_compatible(unsigned short type)
{
      return type == ARPHRD_ETHER || type == ARPHRD_INFINIBAND;
}

2) And use it in bond_enslave() and team_port_add()

Thanks.

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