diff --git a/core/fxcodec/lbmp/fx_bmp.cpp b/core/fxcodec/lbmp/fx_bmp.cpp
index fb64b36..2b072a4 100644
--- a/core/fxcodec/lbmp/fx_bmp.cpp
+++ b/core/fxcodec/lbmp/fx_bmp.cpp
@@ -358,6 +358,8 @@
         }
         green_bits += blue_bits;
         red_bits += green_bits;
+        if (blue_bits > 8 || green_bits < 8 || red_bits < 8)
+          return 2;
         blue_bits = 8 - blue_bits;
         green_bits -= 8;
         red_bits -= 8;