Re: [PATCH v1 1/2] platform/x86: wmi: Break possible infinite loop when parsing GUID

[Andy Shevchenko]

On Tue, Jul 04, 2023 at 01:02:11PM +0200, Hans de Goede wrote:
> On 6/22/23 17:00, Andy Shevchenko wrote:
> > On Thu, Jun 22, 2023 at 11:43:20AM +0300, Andy Shevchenko wrote:
> >> On Wed, Jun 21, 2023 at 11:50:51PM +0200, Armin Wolf wrote:

...

> >> I think that WARN_ON() is a bit bogus. First of all, it can be easily
> >> transformed to BUG()-equivalent with panic_on_oops and hence kill the
> >> entire system. If we need the message about wrong GUID format, it should
> >> be done elsewhere (modpost ?). I.o.w. we shan't expect that code,
> >> controlled by us, shoots to our foot.
> > 
> > Additional info. There will be another driver elsewhere that may use similar
> > API and also needs GUID in device ID table.
> > 
> > Looking into that implementation it seems that validation should be made in
> > file2alias.c for WMI and reused by that driver.
> > 
> > So, taking into account that we have no wrong IDs so far, I would drop
> > WARN_ON() here and guarantee that file2alias.c will be changed to validate
> > the GUID one way or the other.
> > 
> > Would it work? Hans, what is your comment here?
> 
> 
> I agree that warning on malformed GUIDs does not belong here and
> your patch already drops the WARN_ON while switching to the new
> guid_parse_and_compare() helper.
> 
> So I'll go and merge this into my fixes branch once rc1 is out.

Thank you!

-- 
With Best Regards,
Andy Shevchenko