Add pointer check for NULL before dereference it.

Signed-off-by: ydong10
Reviewed-by: rsun3, lgao4

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12472 6f19259b-4bc3-4df7-8a09-765794883524

MdeModulePkg/Universal/Network/ArpDxe/ArpImpl.c

@@ -533,6 +533,8 @@ ArpMatchAddress (
   IN NET_ARP_ADDRESS  *AddressTwo
   )
 {
+  ASSERT (AddressOne != NULL && AddressTwo != NULL);
+
   if ((AddressOne->Type != AddressTwo->Type) ||
     (AddressOne->Length != AddressTwo->Length)) {
     //