Re: [PATCH v4] iio: frequency: admv1013: fix NULL pointer dereference on str

[Andy Shevchenko]

On Thu, Mar 5, 2026 at 11:15 AM Antoniu Miclaus
<antoniu.miclaus@xxxxxxxxxx> wrote:
>
> When device_property_read_string() fails, str is left uninitialized
> but the code falls through to strcmp(str, ...), dereferencing a garbage
> pointer. Replace manual read/strcmp with
> device_property_match_property_string() and consolidate the SE mode
> enums into a single sequential enum, mapping to hardware register
> values via a switch consistent with other bitfields in the driver.

...

> static int admv1013_init(struct admv1013_state *st, int vcm_uv)

> -       data = FIELD_PREP(ADMV1013_QUAD_SE_MODE_MSK, st->quad_se_mode);
> +       switch (st->quad_se_mode) {
> +       case ADMV1013_SE_MODE_POS:
> +               data = 6;
> +               break;
> +       case ADMV1013_SE_MODE_NEG:
> +               data = 9;
> +               break;
> +       case ADMV1013_SE_MODE_DIFF:
> +               data = 12;
> +               break;
> +       default:
> +               return -EINVAL;
> +       }

Oh, I haven't realised that it can be done like this. I have in mind
just to have a switch in the probe, so we don't need to do that again
and again. Otherwise looks good to me.

-- 
With Best Regards,
Andy Shevchenko