Re: [PATCH net 2/2] net: pse-pd: si3474: validate the channels of a PI

[Kory Maincent <kory.maincent@bootlin.com>]

On 10/19/26 18:24, Piotr Kubik wrote:
> si3474_get_of_channels() accepted channel 8, one past the last channel.
> The driver then accessed channel 4 instead: quad 1, channel index 0.
> 
> It also accepted a 4-pair PI whose two channels are not a channel pair
> of one quad. The chip forms a 4-pair port only from channels 0+1 or 2+3
> of a quad (2P/4P mode bit in POWER_ALLOCATION, PORT_REMAP default), and
> the driver sends every register access of a PI to the quad of its first
> channel, so such a PI enabled and measured the wrong channels.
> 
> Reject both at probe.
> 
> Discovered by an AI code review agent; no shipped device tree triggers
> it. Validated and tested on an SDG-9000 board (MediaTek MT7988A, two
> Si3474) with Linux 6.18 and a modified device tree: one chip with a
> channel at reg 8, the other with a 4-pair PI on channels 1 and 2. The
> driver now rejects both at probe, and the unmodified device tree still
> probes all eight PIs. No kernel selftest covers PSE hardware.

Reviewed-by: Kory Maincent <kory.maincent@bootlin.com>

Thank you!
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com