Re: [ros-dev] [ros-diffs] [gedmurphy] 72595: [FLTMGR] - Add stubs for context registration - Add dispatch and device control handlers - Implement the load IOCTL. We can now load minifilters with 'fltmc load <myfilter>'

[Thomas Faber]

On 2016-09-06 18:59, [e-mail] wrote:
> +NTSTATUS
> +HandleLoadUnloadIoctl(_In_ PDEVICE_OBJECT DeviceObject,
>                  _Inout_ PIRP Irp)
>
> +{
> PIO_STACK_LOCATION StackPtr;
> UNICODE_STRING Name;
> PFILTER_NAME FilterName;
> ULONG BufferLength;
> ULONG ControlCode;
> /* Get the IOCTL data from the stack pointer */
> StackPtr = IoGetCurrentIrpStackLocation(Irp);
> BufferLength = StackPtr->Parameters.DeviceIoControl.InputBufferLength;
> ControlCode = StackPtr->Parameters.DeviceIoControl.IoControlCode;
> FLT_ASSERT(ControlCode == IOCTL_LOAD_FILTER || ControlCode == IOCTL_UNLOAD_FILTER);
> /* Make sure the buffer is valid */
> if (BufferLength < sizeof(FILTER_NAME))
>    return STATUS_INVALID_PARAMETER;
> /* Convert the file name buffer into a string */
> FilterName = (PFILTER_NAME)Irp->AssociatedIrp.SystemBuffer;
> Name.Length = FilterName->Length;
> Name.MaximumLength = FilterName->Length;
> Name.Buffer = (PWCH)((PCHAR)FilterName + FIELD_OFFSET(FILTER_NAME, FilterName[0]));

You're missing a check for
BufferLength < FIELD_OFFSET(FILTER_NAME, FilterName[FilterName->Length / sizeof(WCHAR)])
> /* Forward the request to our Flt routines */
> if (ControlCode == IOCTL_LOAD_FILTER)
> {
>    return FltLoadFilter(&Name);
> }
> else
> {
>    return FltUnloadFilter(&Name);
> }
>
> +}