[PATCH] MdeModulePkg/DxeCapsuleLibFmp: Add more check for the UX capsule

[Ruiyu Ni <ruiyu.ni@intel.com>]

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
---
 .../Library/DxeCapsuleLibFmp/DxeCapsuleLib.c        | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleLib.c b/MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleLib.c
index 15dbc00216..555c5971d0 100644
--- a/MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleLib.c
+++ b/MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleLib.c
@@ -330,8 +330,25 @@ DisplayCapsuleImage (
   UINTN                         Width;
   EFI_GRAPHICS_OUTPUT_PROTOCOL  *GraphicsOutput;
 
-  ImagePayload = (DISPLAY_DISPLAY_PAYLOAD *)(CapsuleHeader + 1);
-  PayloadSize = CapsuleHeader->CapsuleImageSize - sizeof(EFI_CAPSULE_HEADER);
+  //
+  // UX capsule doesn't have extended header entries.
+  //
+  if (CapsuleHeader->HeaderSize != sizeof (EFI_CAPSULE_HEADER)) {
+    return EFI_UNSUPPORTED;
+  }
+  ImagePayload = (DISPLAY_DISPLAY_PAYLOAD *)((UINTN) CapsuleHeader + CapsuleHeader->HeaderSize);
+  //
+  // (CapsuleImageSize > HeaderSize) is guaranteed by IsValidCapsuleHeader().
+  //
+  PayloadSize = CapsuleHeader->CapsuleImageSize - CapsuleHeader->HeaderSize;
+
+  //
+  // Make sure the image payload at least contain the DISPLAY_DISPLAY_PAYLOAD header.
+  // Further size check is performed by the logic translating BMP to GOP BLT.
+  //
+  if (PayloadSize <= sizeof (DISPLAY_DISPLAY_PAYLOAD)) {
+    return EFI_INVALID_PARAMETER;
+  }
 
   if (ImagePayload->Version != 1) {
     return EFI_UNSUPPORTED;
-- 
2.16.1.windows.1