Re: [RFC PATCH v1] platform/x86: wmi: Do not register driver with invalid GUID

From: Barnabás Pőcze
Date: Wed Jul 19 2023 - 15:24:24 EST


Hi


2023. július 17., hétfő 13:31 keltezéssel, Andy Shevchenko írta:

> On Mon, Jul 17, 2023 at 11:23:50AM +0000, Barnabás Pőcze wrote:
> > 2023. július 17., hétfő 11:49 keltezéssel, Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> írta:
> > On Sat, Jul 15, 2023 at 09:24:16PM +0000, Barnabás Pőcze wrote:
> > > > Since a WMI driver's ID table contains strings it is relatively
> > > > easy to make mistakes. At the moment, there is no feedback
> > > > if any of the specified GUIDs are invalid (since
> > > > 028e6e204ace1f080cfeacd72c50397eb8ae8883).
> > > >
> > > > So check if the GUIDs in the driver's ID table are valid,
> > > > print all invalid ones, and refuse to register the driver
> > > > if any of the GUIDs are invalid.
> > >
> > > Besides using wrong API (uuid_*() vs. guid_*() one), I don't
> >
> > As far as I can see `guid_parse()` also uses `uuid_is_valid()`, the format is the same.
>
> Then add guid_is_valid() to complete the API. Perhaps with the renaming the
> common part to something else.

But that would be the exact same function. GUIDs are UUIDs, aren't they?


>
> > > think we need to validate it here. Why not in file2alias.c?
> > > [...]
> >
> > 1) that seems like a more complicated change (duplicating `uuid_is_valid()`?);
> > 2) that will only check the GUIDs specified by `MODULE_DEVICE_TABLE()`.
> >
> > Arguably the second point is not that significant since most users will indeed
> > use `MODULE_DEVICE_TABLE()`. But I think the first point has some merit. And
> > furthermore, I think this check should be here regardless of whether file2alias.c
> > also contains an equivalent/similar check.
>
> Why do we need it? We never match against wrong GUID from ACPI, since it would
> be very weird ACPI table.
> [...]

The point is to catch typos in drivers' WMI ID tables.


Regards,
Barnabás Pőcze