X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=MdePkg%2FLibrary%2FUefiDevicePathLibDevicePathProtocol%2FUefiDevicePathLib.c;h=2252d186cbf3215c2091254a5862800779cc20c4;hp=5cc4b35fe492e3ed9fddc40799a109add92684b7;hb=c0cba3d5ddec83e2bf09deb01a25140a71f8b7e6;hpb=0b13fe741b7221514da510c165a55e47a3d377b2

diff --git a/MdePkg/Library/UefiDevicePathLibDevicePathProtocol/UefiDevicePathLib.c b/MdePkg/Library/UefiDevicePathLibDevicePathProtocol/UefiDevicePathLib.c
index 5cc4b35fe4..2252d186cb 100644
--- a/MdePkg/Library/UefiDevicePathLibDevicePathProtocol/UefiDevicePathLib.c
+++ b/MdePkg/Library/UefiDevicePathLibDevicePathProtocol/UefiDevicePathLib.c
@@ -2,7 +2,7 @@
   Library instance that implement UEFI Device Path Library class based on protocol
   gEfiDevicePathUtilitiesProtocolGuid.
 
-  Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
   which accompanies this distribution.  The full text of the license may be found at
@@ -103,17 +103,33 @@ IsDevicePathValid (
 
   ASSERT (DevicePath != NULL);
 
+  if (MaxSize == 0) {
+    MaxSize = MAX_UINTN;
+  }
+
+  //
+  // Validate the input size big enough to touch the first node.
+  //
+  if (MaxSize < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {
+    return FALSE;
+  }
+
   for (Count = 0, Size = 0; !IsDevicePathEnd (DevicePath); DevicePath = NextDevicePathNode (DevicePath)) {
     NodeLength = DevicePathNodeLength (DevicePath);
     if (NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {
       return FALSE;
     }
 
-    if (MaxSize > 0) {
-      Size += NodeLength;
-      if (Size + END_DEVICE_PATH_LENGTH > MaxSize) {
-        return FALSE;
-      }
+    if (NodeLength > MAX_UINTN - Size) {
+      return FALSE;
+    }
+    Size += NodeLength;
+
+    //
+    // Validate next node before touch it.
+    //
+    if (Size > MaxSize - END_DEVICE_PATH_LENGTH ) {
+      return FALSE;
     }
 
     if (PcdGet32 (PcdMaximumDevicePathNodeCount) > 0) {