[PATCH] MdeModulePkg DxeCapsuleLibFmp: Refine the code to check FmpImageSize.

[Star Zeng <star.zeng@intel.com>]

The code to check FmpImageSize again OFFSET_OF
(EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER, UpdateHardwareInstance)
can be refined to check against FmpImageHeaderSize.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
---
 MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleLib.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleLib.c b/MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleLib.c
index a1347b5ce67c..ee3adce2a2f2 100644
--- a/MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleLib.c
+++ b/MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleLib.c
@@ -268,10 +268,6 @@ ValidateFmpCapsule (
     }
     FmpImageSize = (UINTN)EndOfPayload - ItemOffsetList[Index];
 
-    if (FmpImageSize < OFFSET_OF(EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER, UpdateHardwareInstance)) {
-      DEBUG((DEBUG_ERROR, "FmpImageSize(0x%lx) < EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER\n", FmpImageSize));
-      return EFI_INVALID_PARAMETER;
-    }
     FmpImageHeaderSize = sizeof(EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER);
     if ((ImageHeader->Version > EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER_INIT_VERSION) ||
         (ImageHeader->Version < 1)) {
@@ -281,6 +277,10 @@ ValidateFmpCapsule (
     if (ImageHeader->Version < EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER_INIT_VERSION) {
       FmpImageHeaderSize = OFFSET_OF(EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER, UpdateHardwareInstance);
     }
+    if (FmpImageSize < FmpImageHeaderSize) {
+      DEBUG((DEBUG_ERROR, "FmpImageSize(0x%lx) < FmpImageHeaderSize(0x%x)\n", FmpImageSize, FmpImageHeaderSize));
+      return EFI_INVALID_PARAMETER;
+    }
 
     // No overflow
     if (FmpImageSize != (UINT64)FmpImageHeaderSize + (UINT64)ImageHeader->UpdateImageSize + (UINT64)ImageHeader->UpdateVendorCodeSize) {
-- 
2.7.0.windows.1