From 519abb5b4aba50f540fec1f5ce3988d9c5e46f91 Mon Sep 17 00:00:00 2001
From: Thomas Faber <thomas.faber@reactos.org>
Date: Thu, 14 Apr 2016 15:18:53 +0000
Subject: [PATCH] [NTOS:IO] - Avoid excessive stack usage in
 IopInitializeDriverModule.

svn path=/trunk/; revision=71157
---
 reactos/ntoskrnl/io/iomgr/driver.c | 33 ++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/reactos/ntoskrnl/io/iomgr/driver.c b/reactos/ntoskrnl/io/iomgr/driver.c
index d84eddc6784..22f5a4078ea 100644
--- a/reactos/ntoskrnl/io/iomgr/driver.c
+++ b/reactos/ntoskrnl/io/iomgr/driver.c
@@ -463,8 +463,7 @@ IopInitializeDriverModule(
     IN BOOLEAN FileSystemDriver,
     OUT PDRIVER_OBJECT *DriverObject)
 {
-    const WCHAR ServicesKeyName[] = L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\";
-    WCHAR NameBuffer[MAX_PATH];
+    static const WCHAR ServicesKeyName[] = L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\";
     UNICODE_STRING DriverName;
     UNICODE_STRING RegistryKey;
     PDRIVER_INITIALIZE DriverEntry;
@@ -477,7 +476,9 @@ IopInitializeDriverModule(
     {
         RegistryKey.Length = 0;
         RegistryKey.MaximumLength = sizeof(ServicesKeyName) + ServiceName->Length;
-        RegistryKey.Buffer = ExAllocatePool(PagedPool, RegistryKey.MaximumLength);
+        RegistryKey.Buffer = ExAllocatePoolWithTag(PagedPool,
+                                                   RegistryKey.MaximumLength,
+                                                   TAG_IO);
         if (RegistryKey.Buffer == NULL)
         {
             return STATUS_INSUFFICIENT_RESOURCES;
@@ -487,26 +488,35 @@ IopInitializeDriverModule(
     }
     else
     {
-        RtlInitUnicodeString(&RegistryKey, NULL);
+        RtlInitEmptyUnicodeString(&RegistryKey, NULL, 0);
     }
 
     /* Create ModuleName string */
     if (ServiceName && ServiceName->Length > 0)
     {
+        DriverName.Length = 0;
+        DriverName.MaximumLength = sizeof(FILESYSTEM_ROOT_NAME) + ServiceName->Length;
+        DriverName.Buffer = ExAllocatePoolWithTag(PagedPool,
+                                                  DriverName.MaximumLength,
+                                                  TAG_IO);
+        if (DriverName.Buffer == NULL)
+        {
+            RtlFreeUnicodeString(&RegistryKey);
+            return STATUS_INSUFFICIENT_RESOURCES;
+        }
+
         if (FileSystemDriver != FALSE)
-            wcscpy(NameBuffer, FILESYSTEM_ROOT_NAME);
+            RtlAppendUnicodeToString(&DriverName, FILESYSTEM_ROOT_NAME);
         else
-            wcscpy(NameBuffer, DRIVER_ROOT_NAME);
-
-        RtlInitUnicodeString(&DriverName, NameBuffer);
-        DriverName.MaximumLength = sizeof(NameBuffer);
-
+            RtlAppendUnicodeToString(&DriverName, DRIVER_ROOT_NAME);
         RtlAppendUnicodeStringToString(&DriverName, ServiceName);
 
         DPRINT("Driver name: '%wZ'\n", &DriverName);
     }
     else
-        DriverName.Length = 0;
+    {
+        RtlInitEmptyUnicodeString(&DriverName, NULL, 0);
+    }
 
     Status = IopCreateDriver(DriverName.Length > 0 ? &DriverName : NULL,
                              DriverEntry,
@@ -515,6 +525,7 @@ IopInitializeDriverModule(
                              ModuleObject,
                              &Driver);
     RtlFreeUnicodeString(&RegistryKey);
+    RtlFreeUnicodeString(&DriverName);
 
     *DriverObject = Driver;
     if (!NT_SUCCESS(Status))