X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=MdeModulePkg%2FCore%2FDxe%2FMisc%2FMemoryProtection.c;h=455ed35f9a36541272ea21effd7d13f23f5caf84;hp=a4705bc7ce343f002fb933829e9cecfaa3ec7987;hb=a6a0a59756173148099d66638fcb4b3bca52434b;hpb=9b17c6511d50db493c49324aaf81c50c3676a111

diff --git a/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c b/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c
index a4705bc7ce..455ed35f9a 100644
--- a/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c
+++ b/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c
@@ -48,6 +48,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #include <Protocol/SimpleFileSystem.h>
 
 #include "DxeMain.h"
+#include "Mem/HeapGuard.h"
 
 #define CACHE_ATTRIBUTE_MASK   (EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT | EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_WP)
 #define MEMORY_ATTRIBUTE_MASK  (EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RO)
@@ -1202,6 +1203,27 @@ ApplyMemoryProtectionPolicy (
     return EFI_SUCCESS;
   }
 
+  //
+  // Don't overwrite Guard pages, which should be the first and/or last page,
+  // if any.
+  //
+  if (IsHeapGuardEnabled ()) {
+    if (IsGuardPage (Memory))  {
+      Memory += EFI_PAGE_SIZE;
+      Length -= EFI_PAGE_SIZE;
+      if (Length == 0) {
+        return EFI_SUCCESS;
+      }
+    }
+
+    if (IsGuardPage (Memory + Length - EFI_PAGE_SIZE))  {
+      Length -= EFI_PAGE_SIZE;
+      if (Length == 0) {
+        return EFI_SUCCESS;
+      }
+    }
+  }
+
   //
   // Update the executable permissions according to the DXE memory
   // protection policy, but only if