Update: All OSR seminars are now exclusively delivered online with a live instructors. One of the most common requests that we’ve received over the years about our seminars has been to allow people to attend remotely, online, via the Internet. But we waited, quite literally for years, until we had felt we could give attendees […]
Unexpected FltGetFileNameInformation Behavior for Network Renames (oh, and Tunnel Caching too)
A couple of weeks ago I was teaching our Developing file System Minifilters for Windows seminar here in Manchester, NH. A student asked a question about a behavior they were seeing when calling FltGetFileNameInformation after a rename operation on the network. Much to their surprise, the name returned was the old name for the file […]
How L1 Terminal Fault (L1TF) Mitigation and WinDbg Wasted My Morning (a.k.a. Yak Shaving: WinDbg Edition)
I’ve been doing some research into the Windows Filtering Platform and the information available at each of the various filtering layers. In particular, I’ve been focusing on the information available in Windows 7 as that predates some ETW trace points that contain interesting network event data. After attaching a filter to the FWPM_LAYER_ALE_AUTH_CONNECT_V4 layer, I […]
Three-Plus Years Later… Driver Signing Still Baffles
It was back in 2015 that I wrote my first set of blog posts on Windows driver signing. Then I wrote some more in 2016. And then in 2017 I wrote what I thought was the ultimate, definitive, and incredibly simple blog post entitled Attestation Signing — It’s NOT a Mystery. Still, all these years […]
Withdrawing From the Microsoft MVP Program
When I was first named a Microsoft Most Valuable Professional, back in the early 2000’s, I was very proud. Really, I was. There was a cohort of smart, generous, and engaged engineers who were named “DDK MVPs” at the same time that I was appointed. And I am pleased to say that I personally recommended […]
PSA: FsRtlIsNameInExpression Can Raise an Exception
Well, THIS one was a surprise…After triggering a memory leak in a driver, the system surprisingly crashed due to a call to FsRtlIsNameInExpression: As best we could tell we were passing valid input to FsRtlIsNameInExpression, so what’s up? The answer lies in the exception code: STATUS_NO_MEMORY (0xC0000017). A quick scan of the disassembly shows that yes […]
NTFS Status Debugging
As a file system filter developer, one of the great pains in life is when a file system operation fails deep in the bowels of the file system. For example, say I’m trying to rename a file with FltSetInformationFile for FileRenameInformation and I get back STATUS_ACCESS_DENIED. How do I track that down? Sure, I could try […]
Check out the new Virtual Hardware Lab Kit (VHLK)
A big complaint I’ve always had about the HLKs is the overhead of getting a system provisioned as the HLK controller. This is made even worse now by the blistering speed with which Windows feature updates are coming, thus requiring the installation of yet another HLK controller for compliance testing every few months. I was […]
It’s 1809… A New WDK Awaits You… Don’t Be Afraid!
Well, OK… It’s not really 1809 anymore. It’s actually 1810 when I’m writing this. But whatever. There’s a new WDK among us. Before you can install WDK 1809, you’ll need to be running Visual Studio 15.8 and you’ll need to manually install the latest SDK (the version is Windows 10.0.17763.1, which is the 1809 SDK). […]
Ready for the Community Move?
We’re ready… well, at least we think we’re ready. Are YOU? New web site: community.osr.com Questions/Comments/Issues: CommunityMove@osr.com To summarize key points about the move: The move is scheduled to take place on 19 September 2018. You can visit the new site today to see how it looks, but you will not be able to login […]
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