[PATCH 1/2] ntoskrnl.exe: Track drivers created with IoCreateDriver

[Aric Stewart]

Thanks for the review!


On 2/28/16 9:30 PM, Sebastian Lackner wrote:
> On 26.02.2016 21:22, Aric Stewart wrote:
>> Signed-off-by: Aric Stewart <aric at codeweavers.com>
>> ---
>>   dlls/ntoskrnl.exe/ntoskrnl.c | 64 +++++++++++++++++++++++++++++++++-----------
>>   1 file changed, 48 insertions(+), 16 deletions(-)
>>
>>
>>
>> 0002-ntoskrnl.exe-Track-drivers-created-with-IoCreateDriver.txt
>>
>>
>> diff --git a/dlls/ntoskrnl.exe/ntoskrnl.c b/dlls/ntoskrnl.exe/ntoskrnl.c
>> index 3bee2bf..49c8cab 100644
>> --- a/dlls/ntoskrnl.exe/ntoskrnl.c
>> +++ b/dlls/ntoskrnl.exe/ntoskrnl.c
>> @@ -72,6 +72,16 @@ static DWORD request_thread;
>>   static DWORD client_tid;
>>   static DWORD client_pid;
>>   
>> +typedef struct _created_driver {
>> +    struct list entry;
>> +
>> +    UNICODE_STRING driver_name;
>> +    DRIVER_OBJECT *driver_obj;
>> +    DRIVER_EXTENSION *driver_extension;
> 
> Isn't it possible to add the DRIVER_OBJECT and DRIVER_EXTENSION struct directly
> (without pointer), to avoid multiple memory allocations?
> 

Yeah, That would be just fine, to have it part of the base structure instead of a separate pointer. 

> I would also suggest to use a more meaningful name than "created_driver", and
> you also don't really need the typedef. Something like "struct wine_driver"
> would make more sense for example, but probably you have a better idea. ;)
> 
>> +} created_driver;
>> +
>> +struct list created_drivers = LIST_INIT(created_drivers);
>> +
>>   #ifdef __i386__
>>   #define DEFINE_FASTCALL1_ENTRYPOINT( name ) \
>>       __ASM_STDCALL_FUNC( name, 4, \
>> @@ -818,36 +828,47 @@ PIRP WINAPI IoBuildSynchronousFsdRequest(ULONG majorfunc, PDEVICE_OBJECT device,
>>    */
>>   NTSTATUS WINAPI IoCreateDriver( UNICODE_STRING *name, PDRIVER_INITIALIZE init )
>>   {
>> -    DRIVER_OBJECT *driver;
>> -    DRIVER_EXTENSION *extension;
>> +    created_driver *driver;
>>       NTSTATUS status;
>>   
>>       TRACE("(%s, %p)\n", debugstr_us(name), init);
>>   
>>       if (!(driver = RtlAllocateHeap( GetProcessHeap(), HEAP_ZERO_MEMORY,
>> -                                    sizeof(*driver) + sizeof(*extension) )))
>> +                                    sizeof(*driver) )))
>> +        return STATUS_NO_MEMORY;
>> +
>> +    if (!(driver->driver_obj = RtlAllocateHeap( GetProcessHeap(), HEAP_ZERO_MEMORY,
>> +                                    sizeof(*driver->driver_obj) + sizeof(*driver->driver_extension) )))
>> +    {
>> +        RtlFreeHeap( GetProcessHeap(), 0, driver );
>>           return STATUS_NO_MEMORY;
>> +    }
>>   
>> -    if ((status = RtlDuplicateUnicodeString( 1, name, &driver->DriverName )))
>> +    if ((status = RtlDuplicateUnicodeString( 1, name, &driver->driver_name )))
>>       {
>> +        RtlFreeHeap( GetProcessHeap(), 0, driver->driver_obj );
>>           RtlFreeHeap( GetProcessHeap(), 0, driver );
>>           return status;
>>       }
>>   
>> -    extension = (DRIVER_EXTENSION *)(driver + 1);
>> -    driver->Size            = sizeof(*driver);
>> -    driver->DriverInit      = init;
>> -    driver->DriverExtension = extension;
>> -    extension->DriverObject   = driver;
>> -    extension->ServiceKeyName = driver->DriverName;
>> +    driver->driver_extension = (DRIVER_EXTENSION *)((BYTE*)driver->driver_obj + sizeof(*driver->driver_obj));
>> +    driver->driver_obj->DriverName      = driver->driver_name;
>> +    driver->driver_obj->Size            = sizeof(*driver->driver_obj);
>> +    driver->driver_obj->DriverInit      = init;
>> +    driver->driver_obj->DriverExtension = driver->driver_extension;
>> +    driver->driver_extension->DriverObject   = driver->driver_obj;
>> +    driver->driver_extension->ServiceKeyName = driver->driver_name;
>>   
>> -    status = driver->DriverInit( driver, name );
>> +    status = driver->driver_obj->DriverInit( driver->driver_obj, name );
>>   
>>       if (status)
>>       {
>> -        RtlFreeUnicodeString( &driver->DriverName );
>> +        RtlFreeUnicodeString( &driver->driver_name );
>> +        RtlFreeHeap( GetProcessHeap(), 0, driver->driver_obj );
>>           RtlFreeHeap( GetProcessHeap(), 0, driver );
>>       }
>> +
>> +    list_add_tail( &created_drivers, &driver->entry );
> 
> Such a global list will need locking.
> 

You think that a basic critical section would be sufficient or do you think other locking would be better?


-aric

>>       return status;
>>   }
>>   
>> @@ -855,12 +876,23 @@ NTSTATUS WINAPI IoCreateDriver( UNICODE_STRING *name, PDRIVER_INITIALIZE init )
>>   /***********************************************************************
>>    *           IoDeleteDriver   (NTOSKRNL.EXE.@)
>>    */
>> -void WINAPI IoDeleteDriver( DRIVER_OBJECT *driver )
>> +void WINAPI IoDeleteDriver( DRIVER_OBJECT *driver_object )
>>   {
>> -    TRACE("(%p)\n", driver);
>> +    created_driver *driver, *next;
>> +
>> +    TRACE("(%p)\n", driver_object);
>> +
> 
> By putting the driver_object in the same struct, you could use CONTAINING_RECORD here.
> Also, a lock will be required while unlinking the driver from the list.
> 
>> +    LIST_FOR_EACH_ENTRY_SAFE(driver, next, &created_drivers, created_driver, entry)
>> +    {
>> +        if (driver->driver_obj == driver_object)
>> +        {
>> +            list_remove( &driver->entry );
>> +            RtlFreeUnicodeString( &driver->driver_name);
>> +            break;
>> +        }
>> +    }
>>   
>> -    RtlFreeUnicodeString( &driver->DriverName );
>> -    RtlFreeHeap( GetProcessHeap(), 0, driver );
>> +    RtlFreeHeap( GetProcessHeap(), 0, driver_object );
>>   }
>>   
>>   
>>
>>
>>
>