From c64577a5547865f586bc61f6f6949a911190e33e Mon Sep 17 00:00:00 2001
From: Vladimir Serbinenko <phcoder@gmail.com>
Date: Fri, 25 Oct 2013 20:18:30 +0200
Subject: [PATCH] 	* grub-core/io/gzio.c (test_zlib_header): Use undigned
 modulo rather 	than signed.

---
 ChangeLog           | 5 +++++
 grub-core/io/gzio.c | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 3aa8197da..1a01bf70b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2013-10-25  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	* grub-core/io/gzio.c (test_zlib_header): Use undigned modulo rather
+	than signed.
+
 2013-10-25  Jon McCune <jonmccune@google.com>
 
 	* docs/grub.texi: Cleanup security documentation around signatures.
diff --git a/grub-core/io/gzio.c b/grub-core/io/gzio.c
index ef5872a53..50dc31ad4 100644
--- a/grub-core/io/gzio.c
+++ b/grub-core/io/gzio.c
@@ -1178,7 +1178,7 @@ test_zlib_header (grub_gzio_t gzio)
       return 0;
     }
 
-  if ((cmf * 256 + flg) % 31)
+  if ((cmf * 256U + flg) % 31U)
     {
       grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, N_("unsupported gzip format"));
       return 0;