[Patch 2/2] NetworkPkg: Check for NULL pointer before dereference it.

[Fu Siyuan <siyuan.fu@intel.com>]

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Fu Siyuan <siyuan.fu@intel.com>
Cc: Ye Ting <ting.ye@intel.com>
Cc: Zhang Lubo <lubo.zhang@intel.com>
Cc: Wu Jiaxin <jiaxin.wu@intel.com>
---
 NetworkPkg/UefiPxeBcDxe/PxeBcImpl.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/NetworkPkg/UefiPxeBcDxe/PxeBcImpl.c b/NetworkPkg/UefiPxeBcDxe/PxeBcImpl.c
index 52095c5..0552174 100644
--- a/NetworkPkg/UefiPxeBcDxe/PxeBcImpl.c
+++ b/NetworkPkg/UefiPxeBcDxe/PxeBcImpl.c
@@ -2013,10 +2013,14 @@ EfiPxeBcSetStationIP (
     return EFI_INVALID_PARAMETER;
   }
 
-  if (!Mode->UsingIpv6 && NewStationIp != NULL && !NetIp4IsUnicast (NTOHL (NewStationIp->Addr[0]), NTOHL (NewSubnetMask->Addr[0]))) {
-    return EFI_INVALID_PARAMETER;
+  if (!Mode->UsingIpv6 && NewStationIp != NULL) {
+    if (IP4_IS_UNSPECIFIED(NTOHL (NewStationIp->Addr[0])) || 
+        IP4_IS_LOCAL_BROADCAST(NTOHL (NewStationIp->Addr[0])) ||
+        (NewSubnetMask != NULL && !NetIp4IsUnicast (NTOHL (NewStationIp->Addr[0]), NTOHL (NewSubnetMask->Addr[0])))) {
+      return EFI_INVALID_PARAMETER;
+    }
   }
-
+  
   if (!Mode->Started) {
     return EFI_NOT_STARTED;
   }
-- 
2.7.4.windows.1