From 29056ed2de064a03301e96919a61c2d188e4b66e Mon Sep 17 00:00:00 2001
From: xdu2 <xdu2@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Fri, 25 Dec 2009 09:49:38 +0000
Subject: [PATCH] Add check before free DevicePath (TCP child sock will have no
 device path installed)

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9617 6f19259b-4bc3-4df7-8a09-765794883524
---
 .../Universal/Network/Tcp4Dxe/Tcp4Dispatcher.c   | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/MdeModulePkg/Universal/Network/Tcp4Dxe/Tcp4Dispatcher.c b/MdeModulePkg/Universal/Network/Tcp4Dxe/Tcp4Dispatcher.c
index d38c10172e..2b924c4b4b 100644
--- a/MdeModulePkg/Universal/Network/Tcp4Dxe/Tcp4Dispatcher.c
+++ b/MdeModulePkg/Universal/Network/Tcp4Dxe/Tcp4Dispatcher.c
@@ -227,14 +227,16 @@ Tcp4FlushPcb (
     RemoveEntryList (&Tcb->List);
 
     //
-    // Uninstall the device path protocl.
+    // Uninstall the device path protocol.
     //
-    gBS->UninstallProtocolInterface (
-           Sock->SockHandle,
-           &gEfiDevicePathProtocolGuid,
-           Sock->DevicePath
-           );
-    FreePool (Sock->DevicePath);
+    if (Sock->DevicePath != NULL) {
+      gBS->UninstallProtocolInterface (
+             Sock->SockHandle,
+             &gEfiDevicePathProtocolGuid,
+             Sock->DevicePath
+             );
+      FreePool (Sock->DevicePath);
+    }
 
     TcpSetVariableData (TcpProto->TcpService);
   }