From: Mike Turner <miketur@microsoft.com>
Date: Tue, 11 Dec 2018 06:10:33 +0000 (+0800)
Subject: BaseTools/DevicePath: Add a checking step
X-Git-Tag: edk2-stable201903~239
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=ca67441558cbe7d482ebf9506fee01b82447ddf1

BaseTools/DevicePath: Add a checking step

Add a checking step in DevicePathUtilities.c
to verify DevicePath.
https://bugzilla.tianocore.org/show_bug.cgi?id=1372

v2: Remove ASSERT() and the redundant checking step.
    Update related description.

Cc: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
---

diff --git a/BaseTools/Source/C/DevicePath/DevicePathUtilities.c b/BaseTools/Source/C/DevicePath/DevicePathUtilities.c
index f8a41ff97d..3b3abc67ea 100644
--- a/BaseTools/Source/C/DevicePath/DevicePathUtilities.c
+++ b/BaseTools/Source/C/DevicePath/DevicePathUtilities.c
@@ -36,12 +36,13 @@ CONST EFI_DEVICE_PATH_PROTOCOL  mUefiDevicePathLibEndDevicePath = {
 
 /**
   Determine whether a given device path is valid.
-  If DevicePath is NULL, then ASSERT().
 
   @param  DevicePath  A pointer to a device path data structure.
   @param  MaxSize     The maximum size of the device path data structure.
 
   @retval TRUE        DevicePath is valid.
+  @retval FALSE       DevicePath is NULL.
+  @retval FALSE       Maxsize is less than sizeof(EFI_DEVICE_PATH_PROTOCOL).
   @retval FALSE       The length of any node node in the DevicePath is less
                       than sizeof (EFI_DEVICE_PATH_PROTOCOL).
   @retval FALSE       If MaxSize is not zero, the size of the DevicePath
@@ -59,19 +60,17 @@ IsDevicePathValid (
   UINTN Size;
   UINTN NodeLength;
 
-  ASSERT (DevicePath != NULL);
-
-  if (MaxSize == 0) {
-    MaxSize = MAX_UINT32;
- }
-
   //
-  // Validate the input size big enough to touch the first node.
+  //  Validate the input whether exists and its size big enough to touch the first node
   //
-  if (MaxSize < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {
+  if (DevicePath == NULL || (MaxSize > 0 && MaxSize < END_DEVICE_PATH_LENGTH)) {
     return FALSE;
   }
 
+  if (MaxSize == 0) {
+    MaxSize = MAX_UINT32;
+  }
+
   for (Count = 0, Size = 0; !IsDevicePathEnd (DevicePath); DevicePath = NextDevicePathNode (DevicePath)) {
     NodeLength = DevicePathNodeLength (DevicePath);
     if (NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {