The free OSR Learning Library has more than 50 articles on a wide variety of topics about writing and debugging device drivers and Minifilters. From introductory level to advanced. All the articles have been recently reviewed and updated, and are written using the clear and definitive style you've come to expect from OSR over the years.
Check out The OSR Learning Library at: https://www.osr.com/osr-learning-library/
I'm trying to intercept calls to FindFirstFile/ZwQueryDirectoryFile from a specific application from Minifilter. The goal is for the application to see a folder that doesn't exist. So if the app enumerates files and folders from an empty folder C:\Temp, that application shouldn't see that the folder is empty, instead it should see a folder in that directory (that I will provide in output result).
Now I understand that I need to modify DirectoryBuffer or Mdl buffer pointed by MdlAddress. Basically I need to return one more **FILE_BOTH_DIR_INFORMATION ** structure instance to the caller. Problem is that those buffers comes with fixed size, so I can not add anything in them.
So my question is:
What options do I have. Should I allocate a larger memory from non-paged pool and replace the DirectoryBuffer pointer in post operation (same with Mdl)? Will the caller be able to access that memory?
If so, what should I do with original buffer, should I free it?
If not how can I return a larger buffer to the caller in user mode?
I'm lost, any help would be greatly appreciated.
|Upcoming OSR Seminars|
|OSR has suspended in-person seminars due to the Covid-19 outbreak. But, don't miss your training! Attend via the internet instead!|
|Writing WDF Drivers||7 Dec 2020||LIVE ONLINE|
|Internals & Software Drivers||25 Jan 2021||LIVE ONLINE|
|Developing Minifilters||8 March 2021||LIVE ONLINE|