Re: [PATCH v2 2/2] software node: Fix software_node_get_reference_args() with index -1

[Alban Bedel]

On Thu, 18 Jun 2026 20:35:59 +0200
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:

> On Thu, Jun 18, 2026 at 05:20:35PM +0200, Alban Bedel wrote:
> > The bounds check for the index passed to
> > software_node_get_reference_args() was failing when passed UINT_MAX,
> > this in turn would lead to an out of bound access in the property
> > array. Fix the bound check to also cover the UINT_MAX case.  
> 
> ...
> 
> > -	if ((index + 1) * sizeof(*ref) > prop->length)
> > +	if (index >= prop->length / sizeof(*ref))  
> 
> It trades multiplication for division (which might be not always
> power-of-two).

This code is not really performance relevant and using a non trivial
expression lead to the currently buggy code. I find that easy to
understand and obviously correct code is better suited here.

What alternative would you suggest?

Alban