Re: [PATCH v3 3/3] IntelFrameworkModulePkg: Fix misuses of AllocateCopyPool

["Bi, Dandan" <dandan.bi@intel.com>]

Reviewed-by: Dandan Bi <dandan.bi@intel.com>

Thanks,
Dandan

-----Original Message-----
From: Wang, Jian J 
Sent: Wednesday, November 8, 2017 10:12 AM
To: edk2-devel@lists.01.org
Cc: Gao, Liming <liming.gao@intel.com>; Bi, Dandan <dandan.bi@intel.com>
Subject: [PATCH v3 3/3] IntelFrameworkModulePkg: Fix misuses of AllocateCopyPool

> v3:
>    No updates.

> v2:
> a. Use ReallocatePool instead of allocating then copying wherever 
> applicable

AllocateCopyPool(AllocationSize, *Buffer) will copy "AllocationSize" bytes of memory from old "Buffer" to new allocated one. If "AllocationSize" is bigger than size of "Buffer", heap memory overflow occurs during copy.

One solution is to allocate pool first then copy the necessary bytes to new memory. Another is using ReallocatePool instead if old buffer will be freed on spot.

Cc: Liming Gao <liming.gao@intel.com>
Cc: Bi Dandan <dandan.bi@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
---
 .../Universal/BdsDxe/DeviceMngr/DeviceManager.c                | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/IntelFrameworkModulePkg/Universal/BdsDxe/DeviceMngr/DeviceManager.c b/IntelFrameworkModulePkg/Universal/BdsDxe/DeviceMngr/DeviceManager.c
index 125c49db5e..5103c7e5d1 100644
--- a/IntelFrameworkModulePkg/Universal/BdsDxe/DeviceMngr/DeviceManager.c
+++ b/IntelFrameworkModulePkg/Universal/BdsDxe/DeviceMngr/DeviceManager.
+++ c
@@ -480,7 +480,11 @@ AddIdToMacDeviceList (
   } else {
     mMacDeviceList.MaxListLen += MAX_MAC_ADDRESS_NODE_LIST_LEN;
     if (mMacDeviceList.CurListLen != 0) {
-      TempDeviceList = (MENU_INFO_ITEM *)AllocateCopyPool (sizeof (MENU_INFO_ITEM) * mMacDeviceList.MaxListLen, (VOID *)mMacDeviceList.NodeList);
+      TempDeviceList = ReallocatePool (
+                         sizeof (MENU_INFO_ITEM) * mMacDeviceList.CurListLen,
+                         sizeof (MENU_INFO_ITEM) * mMacDeviceList.MaxListLen,
+                         mMacDeviceList.NodeList
+                         );
     } else {
       TempDeviceList = (MENU_INFO_ITEM *)AllocatePool (sizeof (MENU_INFO_ITEM) * mMacDeviceList.MaxListLen);
     }
@@ -491,10 +495,6 @@ AddIdToMacDeviceList (
     TempDeviceList[mMacDeviceList.CurListLen].PromptId = PromptId;  
     TempDeviceList[mMacDeviceList.CurListLen].QuestionId = (EFI_QUESTION_ID) (mMacDeviceList.CurListLen + NETWORK_DEVICE_LIST_KEY_OFFSET);
     
-    if (mMacDeviceList.CurListLen > 0) {
-      FreePool(mMacDeviceList.NodeList);
-    }
-    
     mMacDeviceList.NodeList = TempDeviceList;
   }
   mMacDeviceList.CurListLen ++;
--
2.14.1.windows.1