From 47bfb48ebbcf41bee8c6a084b17262aacb05bf33 Mon Sep 17 00:00:00 2001
From: Dibyamartanda Samanta <dibyaxp@noreply.codingworkshop.git>
Date: Wed, 7 Aug 2024 15:28:55 +0200
Subject: [PATCH] Update NTOSKRNL/CC/ccpinsupport.cpp

Loop was prematurely terminating  due to wrong condition
of if(BeyondLastByte.QuadPart < LocalFileOffset.QuadPart + RemainingLength)
we are mapping across the length,
itroduced some guard checks
if(localbcb != nullptr)
   {
    CcSetDirtyPinnedData(localbcb, nullptr);
    *Bcb = localbcb;
   }  to fix some test case where it was failing
---
 NTOSKRNL/CC/ccpinsupport.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/NTOSKRNL/CC/ccpinsupport.cpp b/NTOSKRNL/CC/ccpinsupport.cpp
index 1173f42..da6aea3 100644
--- a/NTOSKRNL/CC/ccpinsupport.cpp
+++ b/NTOSKRNL/CC/ccpinsupport.cpp
@@ -795,7 +795,7 @@ CcPreparePinWrite(
             }
             return false;
         }
-		if(BeyondLastByte.QuadPart < LocalFileOffset.QuadPart + RemainingLength)
+		if(BeyondLastByte.QuadPart > LocalFileOffset.QuadPart + RemainingLength)
 			break;
 
     } 
@@ -810,8 +810,11 @@ CcPreparePinWrite(
         RtlZeroMemory(*Buffer, Length);
     }
 
+    if(localbcb != nullptr)
+   {
     CcSetDirtyPinnedData(localbcb, nullptr);
     *Bcb = localbcb;
+   }
 
     return true;
 }