bug 2173: WifiInformationElement::DeserializeIfPresent attempts to read beyond the end of buffer

src/network/model/buffer.h

@@ -992,7 +992,7 @@ uint8_t
 Buffer::Iterator::PeekU8 (void)
 {
   NS_ASSERT_MSG (m_current >= m_dataStart &&
-                 m_current <= m_dataEnd,
+                 m_current < m_dataEnd,
                  GetReadErrorMessage ());
 
   if (m_current < m_zeroStart)

src/wifi/model/wifi-information-element.cc

@@ -61,6 +61,10 @@ WifiInformationElement::Deserialize (Buffer::Iterator i)
 Buffer::Iterator
 WifiInformationElement::DeserializeIfPresent (Buffer::Iterator i)
 {
+  if (i.IsEnd ())
+    {
+      return i;
+    }
   Buffer::Iterator start = i;
   uint8_t elementId = i.ReadU8 ();