Re: [PATCH] pmdomain: core: Fix error checking in genpd_dev_pm_attach_by_id()

[Dan Carpenter]

On Thu, May 08, 2025 at 12:14:41PM +0200, Ulf Hansson wrote:
> On Thu, 8 May 2025 at 08:29, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
> >
> > The error checking for of_count_phandle_with_args() does not handle
> > negative error codes correctly.  The problem is that "index" is a u32 so
> > in the condition "if (index >= num_domains)" negative error codes stored
> > in "num_domains" are type promoted to very high positive values and
> > "index" is always going to be valid.
> >
> > Test for negative error codes first and then test if "index" is valid.
> >
> > Fixes: 3ccf3f0cd197 ("PM / Domains: Enable genpd_dev_pm_attach_by_id|name() for single PM domain")
> > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> 
> Thanks for the fix! It looks correct to me!
> 
> What puzzles me though, if this is a real problem I am sure we would
> have been receiving bug reports, don't you think?
> 

I think it would only cause an issue for invalid devicetrees?  So it's
probably not an issue people often see in real life.

regards,
dan carpenter