Kernel filtering a UMDF driver?

NTDEV
1

Hello,

I have an existing WDM class filter driver that is used to block access (i.e.
fail create, read, write, device control, etc.) to certain classes of
devices. Ideally I would be able to leverage this same driver to block
access to devices controlled by UMDF drivers. At first I thought I could
just install the filter as an upper filter to WUDFRd.sys but I read on this
list that this is not allowed. If filtering both WDM devices and UMDF
devices is not possible with a WDM driver, can a single KMDF driver do it?
I would prefer not to have two filters performing the same task if I can
avoid it.

Thanks for reading.

2

No current version of UMDF will allow you to place a kernel mode driver above a UMDF driver in a device stack [we do provide some exceptions for Driver Verifier and other testing tools, but those are “built in”]. This will probably change in the future [it has to for numberous reasons], but that’s how it works today.

3

No - KMDF drivers are still kernel-mode drivers and we don’t currently support a KM driver on top of a UM one.

Sorry,
-p

From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of Jason T.
Sent: Tuesday, October 02, 2007 9:08 AM
To: Windows System Software Devs Interest List
Subject: [ntdev] Kernel filtering a UMDF driver?

Hello,

I have an existing WDM class filter driver that is used to block access (i.e. fail create, read, write, device control, etc.) to certain classes of devices. Ideally I would be able to leverage this same driver to block access to devices controlled by UMDF drivers. At first I thought I could just install the filter as an upper filter to WUDFRd.sys but I read on this list that this is not allowed. If filtering both WDM devices and UMDF devices is not possible with a WDM driver, can a single KMDF driver do it? I would prefer not to have two filters performing the same task if I can avoid it.

Thanks for reading.
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