[Patch 1/3] NetworkPkg/TcpDxe: Check FragmentBuffer for NULL before use

[Jiaxin Wu <jiaxin.wu@intel.com>]

According the Spec, the FragmentBuffers in FragmentTable are allocated
by the application when calling Receive() function. This patch is to
check whether the FragmentBuffer is valid or not.

Cc: Fu Siyuan <siyuan.fu@intel.com>
Cc: Wang Fan <fan.wang@intel.com>
Cc: Ye Ting <ting.ye@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Wu Jiaxin <jiaxin.wu@intel.com>
---
 NetworkPkg/TcpDxe/TcpMain.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/NetworkPkg/TcpDxe/TcpMain.c b/NetworkPkg/TcpDxe/TcpMain.c
index fc3713e..e349d2d 100644
--- a/NetworkPkg/TcpDxe/TcpMain.c
+++ b/NetworkPkg/TcpDxe/TcpMain.c
@@ -38,10 +38,13 @@ TcpChkDataBuf (
   UINT32 Index;
 
   UINT32 Len;
 
   for (Index = 0, Len = 0; Index < FragmentCount; Index++) {
+    if (FragmentTable[Index].FragmentBuffer == NULL) {
+      return EFI_INVALID_PARAMETER;
+    }
     Len = Len + FragmentTable[Index].FragmentLength;
   }
 
   if (DataLen != Len) {
     return EFI_INVALID_PARAMETER;
-- 
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