[rharabien] 51412: [KERNEL32] * Properly check if buffer given to GetComputerName is too small. Fixes hostname.exe if computer name is MAX_COMPUTERNAME_LENGTH long (the default for bootcd since it'...

Author: rharabien
Date: Wed Apr 20 21:31:41 2011
New Revision: 51412

URL: http://svn.reactos.org/svn/reactos?rev=51412&view=rev
Log:
[KERNEL32]
* Properly check if buffer given to GetComputerName is too small. Fixes hostname.exe if computer name is MAX_COMPUTERNAME_LENGTH long (the default for bootcd since it's generated randomly in Setup).
* Simplify it a bit

Modified:
    trunk/reactos/dll/win32/kernel32/misc/computername.c

Modified: trunk/reactos/dll/win32/kernel32/misc/computername.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/dll/win32/kernel32/misc/com...
==============================================================================
--- trunk/reactos/dll/win32/kernel32/misc/computername.c [iso-8859-1] (original)
+++ trunk/reactos/dll/win32/kernel32/misc/computername.c [iso-8859-1] Wed Apr 20 21:31:41 2011
@@ -39,7 +39,7 @@
 GetComputerNameFromRegistry(LPWSTR RegistryKey,
                             LPWSTR ValueNameStr,
                             LPWSTR lpBuffer,
-                            LPDWORD nSize )
+                            LPDWORD nSize)
 {
     PKEY_VALUE_PARTIAL_INFORMATION KeyInfo;
     OBJECT_ATTRIBUTES ObjectAttributes;
@@ -50,7 +50,7 @@
     ULONG ReturnSize;
     NTSTATUS Status;

-    RtlInitUnicodeString(&KeyName,RegistryKey);
+    RtlInitUnicodeString(&KeyName, RegistryKey);
     InitializeObjectAttributes(&ObjectAttributes,
                                &KeyName,
                                OBJ_CASE_INSENSITIVE,
@@ -75,7 +75,7 @@
         return FALSE;
     }

-    RtlInitUnicodeString(&ValueName,ValueNameStr);
+    RtlInitUnicodeString(&ValueName, ValueNameStr);

Status = ZwQueryValueKey(KeyHandle,
                              &ValueName,
@@ -83,35 +83,40 @@
                              KeyInfo,
                              KeyInfoSize,
                              &ReturnSize);
+
+    ZwClose(KeyHandle);
+
     if (!NT_SUCCESS(Status))
     {
-        RtlFreeHeap(RtlGetProcessHeap(), 0, KeyInfo);
-        ZwClose(KeyHandle);
         *nSize = ReturnSize;
-        SetLastErrorByStatus(Status);
-        return FALSE;
-    }
-
-    if (lpBuffer && *nSize > (KeyInfo->DataLength / sizeof(WCHAR)))
-    {
-        *nSize = KeyInfo->DataLength / sizeof(WCHAR) - 1;
-        lpBuffer[*nSize] = 0;
-    }
-    else
-    {
-        RtlFreeHeap(RtlGetProcessHeap(), 0, KeyInfo);
-        ZwClose(KeyHandle);
+        goto failed;
+    }
+
+    if (KeyInfo->Type != REG_SZ)
+    {
+        Status = STATUS_UNSUCCESSFUL;
+        goto failed;
+    }
+
+    if (!lpBuffer || *nSize < (KeyInfo->DataLength / sizeof(WCHAR)))
+    {
         *nSize = ReturnSize;
-        SetLastErrorByStatus(STATUS_BUFFER_OVERFLOW);
-        return FALSE;
-    }
-
-    RtlCopyMemory(lpBuffer, KeyInfo->Data, *nSize * sizeof(WCHAR));
+        Status = STATUS_BUFFER_OVERFLOW;
+        goto failed;
+    }
+
+    *nSize = KeyInfo->DataLength / sizeof(WCHAR) - 1;
+    RtlCopyMemory(lpBuffer, KeyInfo->Data, KeyInfo->DataLength);
+    lpBuffer[*nSize] = 0;

RtlFreeHeap(RtlGetProcessHeap(), 0, KeyInfo);
-    ZwClose(KeyHandle);

return TRUE;
+
+failed:
+    RtlFreeHeap(RtlGetProcessHeap(), 0, KeyInfo);
+    SetLastErrorByStatus(Status);
+    return FALSE;
 }

/*