Re: [PATCH v3 2/2] net: pcs: rzn1-miic: Verify port number from dtb

[Kyle Hendry]

On 02-Sep-26 11:50, Andrew Lunn wrote:
> On Wed, Sep 02, 2026 at 11:37:36AM -0700, Kyle Hendry via B4 Relay wrote:
> > From: Kyle Hendry <khendry@xxxxxxxxxxxxxxxxxxxx>
> >
> > Add check to make sure port number is in range before writing
> > to dt_val array
> >
> > Signed-off-by: Kyle Hendry <khendry@xxxxxxxxxxxxxxxxxxxx>
> > ---
> >   drivers/net/pcs/pcs-rzn1-miic.c | 6 ++++++
> >   1 file changed, 6 insertions(+)
> >
> > diff --git a/drivers/net/pcs/pcs-rzn1-miic.c b/drivers/net/pcs/pcs-rzn1-miic.c
> > index c50b65d064fa..3ee40eb9d545 100644
> > --- a/drivers/net/pcs/pcs-rzn1-miic.c
> > +++ b/drivers/net/pcs/pcs-rzn1-miic.c
> > @@ -692,6 +692,12 @@ static int miic_parse_dt(struct miic *miic, u32 *mode_cfg)
> >                if (of_property_read_u32(conv, "reg", &port))
> >                        continue;
> >
> > +             if (port < miic->of_data->miic_port_start || port > miic->of_data->miic_port_max) {
> > +                     dev_err(miic->dev, "Port number out of range: %d\n", port);
> > +                     kfree(dt_val);
> > +                     return -EINVAL;
> > +             }
> > +
>
> While reviewing this, i noticed:
>
>                  /* Adjust for 0 based index */
>                  dt_val[port + !miic->of_data->miic_port_start] = conf;
>
> Is the ! correct?
>
>          Andrew

Yes, this is correct because dt_val[1] is where the port config entries 
start.

Depending on the SoC, the port numbering might be 0 or 1 based, so this
prevents the input config entry at dt_val[0] from being overwritten. The
logic works out to the same as:

index = port + 1 - miic->of_data->miic_port_start

-Kyle