diff --git a/util/libreboot-utils/lib/rand.c b/util/libreboot-utils/lib/rand.c
index b5d6d459..5bf03239 100644
--- a/util/libreboot-utils/lib/rand.c
+++ b/util/libreboot-utils/lib/rand.c
@@ -70,6 +70,9 @@ retry_rand:
 		goto err; /* possibly unsupported by kernel */
 	}
 
+	if (rc == 0)
+		goto err; /* prevent infinite loop on fatal err */
+
 	if ((off += (size_t)rc) < n)
 		goto retry_rand;