SECVULN-29092 DoS handled for kvs_endpoint.go

agent/kvs_endpoint.go

@@ -234,20 +234,30 @@
 	}
 
 	// Check the content-length
-	if req.ContentLength > int64(s.agent.config.KVMaxValueSize) {
+	maxSize := int64(s.agent.config.KVMaxValueSize)
+
+	switch {
+	case req.ContentLength < 0:
+		return nil, HTTPError{
+			StatusCode: http.StatusBadRequest,
+			Reason:     fmt.Sprintf("Request does not specify content-length .Expected content-length between 1 and %d .", maxSize),
+		}
+	case req.ContentLength > maxSize:
 		return nil, HTTPError{
 			StatusCode: http.StatusRequestEntityTooLarge,
 			Reason: fmt.Sprintf("Request body(%d bytes) too large, max size: %d bytes. See %s.",
-				req.ContentLength, s.agent.config.KVMaxValueSize, "https://developer.hashicorp.com/docs/agent/config/config-files#kv_max_value_size"),
+				req.ContentLength, maxSize, "https://developer.hashicorp.com/docs/agent/config/config-files#kv_max_value_size"),
 		}
-	}
 
-	// Copy the value
-	buf := bytes.NewBuffer(nil)
-	if _, err := io.Copy(buf, req.Body); err != nil {
-		return nil, err
+	default:
+		// Copy the value
+		buf := bytes.NewBuffer(nil)
+		if _, err := io.Copy(buf, req.Body); err != nil {
+			return nil, err
+		}
 	}
+
 	applyReq.DirEnt.Value = buf.Bytes()
 
 	// Make the RPC
 	var out bool