[PATCH 2/2] acpi/wmi: Warn if WMI GUIDs from the Windows driver samples are found

[Armin Wolf]

Am 08.10.24 um 08:30 schrieb ivanhu:

>
>
> On 10/6/24 07:37, Armin Wolf wrote:
>> Some manufacturers like Uniwill just blindly copy the example code
>> from the Windows driver samples without generating new unique WMI GUIDs.
>>
>> This prevents WMI drivers for those WMI GUIDs from being loaded
>> automatically since they cannot reliably identify if a WMI device
>> with such a GUID is actually supported by them.
>>
>> Signed-off-by: Armin Wolf <W_Armin at gmx.de>
>> ---
>>   src/acpi/wmi/wmi.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 46 insertions(+)
>>
>> diff --git a/src/acpi/wmi/wmi.c b/src/acpi/wmi/wmi.c
>> index 7a746354..37752cdd 100644
>> --- a/src/acpi/wmi/wmi.c
>> +++ b/src/acpi/wmi/wmi.c
>> @@ -129,6 +129,25 @@ static fwts_wmi_known_guid
>> fwts_wmi_known_guids[] = {
>>       { NULL, NULL, NULL }
>>   };
>>
>> +/*
>> + *  List of WMI GUIDs used inside the Windows driver samples.
>> + *
>> + *  Some manufacturers just blindly copy those, which prevents their
>> WMI drivers
>> + *  from being loaded automatically since those GUIDs are not unique
>> and cannot
>> + *  be used for reliable WMI device identification.
>> + */
>> +static const char * const windows_example_wmi_guids[] = {
>> +    "ABBC0F6A-8EA1-11D1-00A0-C90629100000",
>> +    "ABBC0F6B-8EA1-11D1-00A0-C90629100000",
>> +    "ABBC0F6C-8EA1-11D1-00A0-C90629100000",
>> +    "ABBC0F6D-8EA1-11D1-00A0-C90629100000",
>> +    "ABBC0F6E-8EA1-11D1-00A0-C90629100000",
>> +    "ABBC0F6F-8EA1-11D1-00A0-C90629100000",
>> +    "ABBC0F70-8EA1-11D1-00A0-C90629100000",
>> +    "ABBC0F71-8EA1-11D1-00A0-C90629100000",
>> +    "ABBC0F72-8EA1-11D1-00A0-C90629100000"
>> +};
>> +
>>   /*
>>    *  WMI flag to text mappings
>>    */
>> @@ -341,6 +360,31 @@ static void wmi_method_exist_count(
>>               guid_str, object_name, wm_name);
>>   }
>>
>> +/*
>> + *  wmi_guid_copycat()
>> + *    Warn if a WMI from the Windows driver samples was found. This
>> usually means that
>> + *    the manufacturer just blindly copied the example code without
>> generating new
>> + *    unique WMI GUIDs.
>> + */
>> +static void wmi_guid_copycat(
>> +    fwts_framework *fw,
>> +    const char *guid_str)
>> +{
>> +    int i;
>> +
>> +    for (i = 0; i < FWTS_ARRAY_SIZE(windows_example_wmi_guids); i++) {
>> +        if (strcmp(guid_str, windows_example_wmi_guids[i]) == 0) {
>> +            fwts_failed(fw, LOG_LEVEL_CRITICAL,
>> +                "WMIExampleGUIDCopycat",
>> +                "GUID %s has likely been copied from the Windows
>> driver samples, "
>> +                "this is a firmware bug that prevents WMI drivers
>> from reliably "
>> +                "detecting such WMI devices since their GUID is not
>> unique.",
>> +                guid_str);
>> +            return;
>
> The severity doesn't appear to be critical; it seems more like a
> medium level issue.
>
I think it should be treated as critical, because reusing such a WMI GUID is like copying
a PCI ID, so it not like a minor issue.

Thanks,
Armin Wolf

>> +        }
>> +    }
>> +}
>> +
>>   /*
>>    *  wmi_no_known_driver()
>>    *    grumble that the kernel does not have a known handler for
>> this GUID
>> @@ -462,6 +506,8 @@ static void wmi_parse_wdg_data(
>>               wmi_block_query_exist_count(fw, info, acpi_object_name,
>> guid_str);
>>           }
>>
>> +        wmi_guid_copycat(fw, guid_str);
>> +
>>           if (info->instance == 0)
>>               fwts_failed(fw, LOG_LEVEL_LOW, "WMIZeroInstance",
>>                       "GUID %s has zero instances", guid_str);
>> --
>> 2.39.5
>>
>>
>