[#3991] Fixed CWE 570 unsignedLessThanZero

diff --git a/src/lib/dhcp/option_data_types.h b/src/lib/dhcp/option_data_types.h
index efbe752364bb84292a255df28ce925990e8b8817..fc4e193a41c94c8748f6d2a852ad048d246d72e4 100644 (file)
--- a/src/lib/dhcp/option_data_types.h
+++ b/src/lib/dhcp/option_data_types.h
@@ -470,7 +470,8 @@ public:
                       " by readInteger is unsupported integer type");
         }
 
-        if (buf.size() < OptionDataTypeTraits<T>::len) {
+        if ((OptionDataTypeTraits<T>::len > 0) &&
+            (buf.size() < OptionDataTypeTraits<T>::len)) {
             isc_throw(isc::dhcp::BadDataTypeCast,
                       "failed to read an integer value from a buffer"
                       << " - buffer is truncated.");