diff --git a/media/libstagefright/SurfaceUtils.cpp b/media/libstagefright/SurfaceUtils.cpp
index 568837a..60ef662 100644
--- a/media/libstagefright/SurfaceUtils.cpp
+++ b/media/libstagefright/SurfaceUtils.cpp
@@ -186,6 +186,10 @@
             break;
         }
 
+        if (img == NULL) {
+            ALOGE("error pushing blank frames: lock returned NULL buffer");
+            break;
+        }
         *img = 0;
 
         err = buf->unlock();