Re: [PATCH net-next v3 04/13] dt-bindings: net: dsa: renesas,rzn1-a5psw: Disallow ports beyond port@4

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] dt-bindings: net: dsa: incomplete schema validation allows bypassing port restrictions via ports node
--

commit b100423001348cf87abe9e11b4f74d424451c2db
Author: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

dt-bindings: net: dsa: renesas,rzn1-a5psw: Disallow ports beyond port@4

Restrict the A5PSW ethernet-ports node to ports 0 through 4, matching the
hardware configuration of four external ports and one CPU/management port.

> diff --git a/Documentation/devicetree/bindings/net/dsa/renesas,rzn1-a5psw.yaml b/Documentation/devicetree/bindings/net/dsa/renesas,rzn1-a5psw.yaml
> index fab6aa6237e93..c5e652c057a94 100644
> --- a/Documentation/devicetree/bindings/net/dsa/renesas,rzn1-a5psw.yaml
> +++ b/Documentation/devicetree/bindings/net/dsa/renesas,rzn1-a5psw.yaml
> @@ -61,7 +61,14 @@ properties:
>  
>    ethernet-ports:
>      type: object
> -    additionalProperties: true
> +    additionalProperties: false

[Severity: Low]
Does this schema allow bypassing the port restrictions if a device tree uses
a node named ports instead of ethernet-ports?

Because dsa.yaml allows either ports or ethernet-ports, and the schema
doesn't list ethernet-ports in the required properties, a devicetree could
define a ports node with a port outside the 0-4 range (e.g. port@5) and
silently pass validation.

The driver in drivers/net/dsa/rzn1_a5psw.c has a hard dependency on
ethernet-ports:

drivers/net/dsa/rzn1_a5psw.c:a5psw_pcs_get() {
    ...
    ports = of_get_child_by_name(a5psw->dev->of_node, "ethernet-ports");
    if (!ports)
        return -EINVAL;
    ...
}

Should ethernet-ports be added to the required properties list to ensure the
validation rules are properly enforced?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261014131906.990077-1-prabhakar.mahadev-lad.rj@bp.renesas.com?part=4