From a824c7ebde0a431413329049252b8c1d3770de82 Mon Sep 17 00:00:00 2001
From: "Hsueh, Hong-chihX" <hong-chihx.hsueh@intel.com>
Date: Wed, 30 Jan 2019 09:19:36 +0800
Subject: [PATCH] MdePkg/BasePeCoffLib: skip runtime relocation if reloc info
 is invalid

Skip runtime relocation for PE images that provide invalid relocation
infomation (ex: RelocDir->Size = 0) to fix a hang observed while booting
Windows.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Neo Hsueh <hong-chihx.hsueh@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Dandan Bi <dandan.bi@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Bi Dandan <dandan.bi@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---
 MdePkg/Library/BasePeCoffLib/BasePeCoff.c | 30 +++++++++++++++--------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/MdePkg/Library/BasePeCoffLib/BasePeCoff.c b/MdePkg/Library/BasePeCoffLib/BasePeCoff.c
index 1bd079ad6a..e2c62e1932 100644
--- a/MdePkg/Library/BasePeCoffLib/BasePeCoff.c
+++ b/MdePkg/Library/BasePeCoffLib/BasePeCoff.c
@@ -1002,7 +1002,7 @@ PeCoffLoaderRelocateImage (
                                                                             RelocDir->VirtualAddress + RelocDir->Size - 1,
                                                                             TeStrippedOffset
                                                                             );
-    if (RelocBase == NULL || RelocBaseEnd == NULL || RelocBaseEnd < RelocBase) {
+    if (RelocBase == NULL || RelocBaseEnd == NULL || (UINTN) RelocBaseEnd < (UINTN) RelocBase) {
       ImageContext->ImageError = IMAGE_ERROR_FAILED_RELOCATION;
       return RETURN_LOAD_ERROR;
     }
@@ -1022,7 +1022,7 @@ PeCoffLoaderRelocateImage (
     // Run the relocation information and apply the fixups
     //
     FixupData = ImageContext->FixupData;
-    while (RelocBase < RelocBaseEnd) {
+    while ((UINTN) RelocBase < (UINTN) RelocBaseEnd) {
 
       Reloc     = (UINT16 *) ((CHAR8 *) RelocBase + sizeof (EFI_IMAGE_BASE_RELOCATION));
       //
@@ -1051,7 +1051,7 @@ PeCoffLoaderRelocateImage (
       //
       // Run this relocation record
       //
-      while (Reloc < RelocEnd) {
+      while ((UINTN) Reloc < (UINTN) RelocEnd) {
         Fixup = PeCoffLoaderImageAddress (ImageContext, RelocBase->VirtualAddress + (*Reloc & 0xFFF), TeStrippedOffset);
         if (Fixup == NULL) {
           ImageContext->ImageError = IMAGE_ERROR_FAILED_RELOCATION;
@@ -1739,13 +1739,23 @@ PeCoffLoaderRelocateImageForRuntime (
   // is present in the image. You have to check the NumberOfRvaAndSizes in
   // the optional header to verify a desired directory entry is there.
   //
+  RelocBase = NULL;
+  RelocBaseEnd = NULL;
   if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_BASERELOC) {
     RelocDir      = DataDirectory + EFI_IMAGE_DIRECTORY_ENTRY_BASERELOC;
-    RelocBase     = (EFI_IMAGE_BASE_RELOCATION *) PeCoffLoaderImageAddress (&ImageContext, RelocDir->VirtualAddress, 0);
-    RelocBaseEnd  = (EFI_IMAGE_BASE_RELOCATION *) PeCoffLoaderImageAddress (&ImageContext,
-                                                                            RelocDir->VirtualAddress + RelocDir->Size - 1,
-                                                                            0
-                                                                            );
+    if ((RelocDir != NULL) && (RelocDir->Size > 0)) {
+      RelocBase     = (EFI_IMAGE_BASE_RELOCATION *) PeCoffLoaderImageAddress (&ImageContext, RelocDir->VirtualAddress, 0);
+      RelocBaseEnd  = (EFI_IMAGE_BASE_RELOCATION *) PeCoffLoaderImageAddress (&ImageContext,
+                                                                              RelocDir->VirtualAddress + RelocDir->Size - 1,
+                                                                              0
+                                                                              );
+    }
+    if (RelocBase == NULL || RelocBaseEnd == NULL || (UINTN) RelocBaseEnd < (UINTN) RelocBase) {
+      //
+      // relocation block is not valid, just return
+      //
+      return;
+    }
   } else {
     //
     // Cannot find relocations, cannot continue to relocate the image, ASSERT for this invalid image.
@@ -1769,7 +1779,7 @@ PeCoffLoaderRelocateImageForRuntime (
     //
     FixupData = RelocationData;
     RelocBaseOrig = RelocBase;
-    while (RelocBase < RelocBaseEnd) {
+    while ((UINTN) RelocBase < (UINTN) RelocBaseEnd) {
       //
       // Add check for RelocBase->SizeOfBlock field.
       //
@@ -1794,7 +1804,7 @@ PeCoffLoaderRelocateImageForRuntime (
       //
       // Run this relocation record
       //
-      while (Reloc < RelocEnd) {
+      while ((UINTN) Reloc < (UINTN) RelocEnd) {
 
         Fixup = PeCoffLoaderImageAddress (&ImageContext, RelocBase->VirtualAddress + (*Reloc & 0xFFF), 0);
         if (Fixup == NULL) {
-- 
2.39.2