From c0590f5de0fd4747fbe78bbfea21d9972daeacf7 Mon Sep 17 00:00:00 2001
From: Timo Kreuzer <timo.kreuzer@reactos.org>
Date: Mon, 23 Sep 2024 21:26:37 +0300
Subject: [PATCH] [NTOS:MM] Fix PTE protection for executable CoW pages

Fixes Blender x64.
See https://jira.reactos.org/browse/CORE-19761
---
 ntoskrnl/mm/section.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/ntoskrnl/mm/section.c b/ntoskrnl/mm/section.c
index 1949d026149..f935e6f30c1 100644
--- a/ntoskrnl/mm/section.c
+++ b/ntoskrnl/mm/section.c
@@ -1509,7 +1509,12 @@ MmAlterViewAttributes(PMMSUPPORT AddressSpace,
                  */
                 Page = MmGetPfnForProcess(Process, Address);
 
-                Protect = PAGE_READONLY;
+                /* Choose protection based on what was requested */
+                if (NewProtect == PAGE_EXECUTE_READWRITE)
+                    Protect = PAGE_EXECUTE_READ;
+                else
+                    Protect = PAGE_READONLY;
+
                 if (IS_SWAP_FROM_SSE(Entry) || PFN_FROM_SSE(Entry) != Page)
                 {
                     Protect = NewProtect;