From 2a1fc2a83df9bd6fc2231e4f0653c6733766fa26 Mon Sep 17 00:00:00 2001
From: Bill Zissimopoulos <billziss@navimatics.com>
Date: Sun, 3 Jan 2016 22:16:17 -0800
Subject: [PATCH] dll: WIP

---
 src/dll/create.c | 33 +++++++++++++++++++++++++++++----
 1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/src/dll/create.c b/src/dll/create.c
index 6973ebda..29a99028 100644
--- a/src/dll/create.c
+++ b/src/dll/create.c
@@ -6,6 +6,15 @@
 
 #include <dll/library.h>
 
+static inline
+BOOLEAN FspIsRootDirectory(PWSTR FileName)
+{
+    for (PWSTR Pointer = FileName; *Pointer; Pointer++)
+        if (L'\\' != *Pointer)
+            return FALSE;
+    return TRUE;
+}
+
 static inline
 NTSTATUS FspCreateCheck(FSP_FILE_SYSTEM *FileSystem,
     FSP_FSCTL_TRANSACT_REQ *Request, BOOLEAN AllowTraverseCheck,
@@ -31,6 +40,9 @@ NTSTATUS FspCreateCheck(FSP_FILE_SYSTEM *FileSystem,
 static NTSTATUS FspFileSystemOpCreate_FileCreate(FSP_FILE_SYSTEM *FileSystem,
     FSP_FSCTL_TRANSACT_REQ *Request)
 {
+    if (FspIsRootDirectory((PWSTR)Request->Buffer))
+        return STATUS_ACCESS_DENIED;
+
     NTSTATUS Result;
     DWORD GrantedAccess;
     FSP_FILE_NODE *FileNode;
@@ -127,6 +139,9 @@ static NTSTATUS FspFileSystemOpCreate_FileOpenIf(FSP_FILE_SYSTEM *FileSystem,
 
     if (Create)
     {
+        if (FspIsRootDirectory((PWSTR)Request->Buffer))
+            return STATUS_ACCESS_DENIED;
+
         Result = FspCreateCheck(FileSystem, Request, FALSE, &GrantedAccess);
         if (!NT_SUCCESS(Result))
             return FspFileSystemSendResponseWithStatus(FileSystem, Request, Result);
@@ -161,6 +176,9 @@ static NTSTATUS FspFileSystemOpCreate_FileOpenIf(FSP_FILE_SYSTEM *FileSystem,
 static NTSTATUS FspFileSystemOpCreate_FileOverwrite(FSP_FILE_SYSTEM *FileSystem,
     FSP_FSCTL_TRANSACT_REQ *Request, BOOLEAN Supersede)
 {
+    if (FspIsRootDirectory((PWSTR)Request->Buffer))
+        return STATUS_ACCESS_DENIED;
+
     NTSTATUS Result;
     DWORD GrantedAccess;
     FSP_FILE_NODE *FileNode;
@@ -172,9 +190,10 @@ static NTSTATUS FspFileSystemOpCreate_FileOverwrite(FSP_FILE_SYSTEM *FileSystem,
     if (!NT_SUCCESS(Result))
         return FspFileSystemSendResponseWithStatus(FileSystem, Request, Result);
 
-    GrantedAccess &= Supersede ?
-        (~DELETE | (Request->Req.Create.DesiredAccess & DELETE)) :
-        (~FILE_WRITE_DATA | (Request->Req.Create.DesiredAccess & FILE_WRITE_DATA));
+    if (0 == (Request->Req.Create.DesiredAccess & MAXIMUM_ALLOWED))
+        GrantedAccess &= Supersede ?
+            (~DELETE | (Request->Req.Create.DesiredAccess & DELETE)) :
+            (~FILE_WRITE_DATA | (Request->Req.Create.DesiredAccess & FILE_WRITE_DATA));
 
     Result = FileSystem->Interface->FileOverwrite(FileSystem, Request, &FileNode);
     if (!NT_SUCCESS(Result))
@@ -202,6 +221,9 @@ static NTSTATUS FspFileSystemOpCreate_FileOverwrite(FSP_FILE_SYSTEM *FileSystem,
 static NTSTATUS FspFileSystemOpCreate_FileOverwriteIf(FSP_FILE_SYSTEM *FileSystem,
     FSP_FSCTL_TRANSACT_REQ *Request)
 {
+    if (FspIsRootDirectory((PWSTR)Request->Buffer))
+        return STATUS_ACCESS_DENIED;
+
     NTSTATUS Result;
     DWORD GrantedAccess;
     FSP_FILE_NODE *FileNode;
@@ -218,7 +240,10 @@ static NTSTATUS FspFileSystemOpCreate_FileOverwriteIf(FSP_FILE_SYSTEM *FileSyste
         Create = TRUE;
     }
     else
-        GrantedAccess &= ~FILE_WRITE_DATA | (Request->Req.Create.DesiredAccess & FILE_WRITE_DATA);
+    {
+        if (0 == (Request->Req.Create.DesiredAccess & MAXIMUM_ALLOWED))
+            GrantedAccess &= ~FILE_WRITE_DATA | (Request->Req.Create.DesiredAccess & FILE_WRITE_DATA);
+    }
 
     if (!Create)
     {