From 81a4d8344baf29e18ae21735fde3384c334491a4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adam=20S=C5=82abo=C5=84?= <asaillen@protonmail.com>
Date: Wed, 18 Jun 2025 23:55:27 +0200
Subject: [PATCH] [NTOS:SE] SeValidSecurityDescriptor: Use relative security
 descriptor header size for length calculation (#8127)

Fixes Win2k3 ntfs.sys on x64
---
 ntoskrnl/se/sd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ntoskrnl/se/sd.c b/ntoskrnl/se/sd.c
index 26f61510482..3c967b1c786 100644
--- a/ntoskrnl/se/sd.c
+++ b/ntoskrnl/se/sd.c
@@ -1035,7 +1035,7 @@ SeValidSecurityDescriptor(
 
     if (Length < SECURITY_DESCRIPTOR_MIN_LENGTH)
     {
-        DPRINT1("Invalid Security Descriptor revision\n");
+        DPRINT1("Invalid Security Descriptor length\n");
         return FALSE;
     }
 
@@ -1051,7 +1051,7 @@ SeValidSecurityDescriptor(
         return FALSE;
     }
 
-    SdLength = sizeof(SECURITY_DESCRIPTOR);
+    SdLength = sizeof(*SecurityDescriptor);
 
     /* Check Owner SID */
     if (!SecurityDescriptor->Owner)