gnu: ghostscript: Add fix for CVE-2015-3228.

* gnu/packages/patches/ghostscript-CVE-2015-3228.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/ghostscript.scm (ghostscript)[source]: Add patch.

gnu-system.am

@@ -444,6 +444,7 @@ dist_patch_DATA =						\
   gnu/packages/patches/gcc-libvtv-runpath.patch			\
   gnu/packages/patches/gcc-5.0-libvtv-runpath.patch		\
   gnu/packages/patches/geoclue-config.patch			\
+  gnu/packages/patches/ghostscript-CVE-2015-3228.patch		\
   gnu/packages/patches/ghostscript-runpath.patch		\
   gnu/packages/patches/gitolite-openssh-6.8-compat.patch	\
   gnu/packages/patches/glib-tests-desktop.patch			\

gnu/packages/ghostscript.scm

@@ -1,6 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2013 Andreas Enge <andreas@enge.fr>
-;;; Copyright © 2014 Mark H Weaver <mhw@netris.org>
+;;; Copyright © 2014, 2015 Mark H Weaver <mhw@netris.org>
 ;;; Copyright © 2015 Ricardo Wurmus <rekado@elephly.net>
 ;;; Copyright © 2015 Ludovic Courtès <ludo@gnu.org>
 ;;;
@@ -129,7 +129,8 @@ printing, and psresize, for adjusting page sizes.")
             (sha256
              (base32
               "0q4jj41p0qbr4mgcc9q78f5zs8cm1g57wgryhsm2yq4lfslm3ib1"))
-            (patches (list (search-patch "ghostscript-runpath.patch")))
+            (patches (map search-patch '("ghostscript-CVE-2015-3228.patch"
+                                         "ghostscript-runpath.patch")))
             (modules '((guix build utils)))
             (snippet
              ;; Honor --docdir.

gnu/packages/patches/ghostscript-CVE-2015-3228.patch

@@ -0,0 +1,32 @@
+The file names in the upstream patch below were modified to apply to GNU
+ghostscript.
+
+From 0c0b0859ae1aba64861599f0e7f74f143f305932 Mon Sep 17 00:00:00 2001
+From: Chris Liddell <chris.liddell@artifex.com>
+Date: Tue, 7 Jul 2015 16:57:41 +0100
+Subject: [PATCH] Bug 696041: sanity check for memory allocation.
+
+In gs_heap_alloc_bytes(), add a sanity check to ensure we don't overflow the
+variable holding the actual number of bytes we allocate.
+
+No cluster differences
+---
+ gs/base/gsmalloc.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/base/gsmalloc.c b/base/gsmalloc.c
+index 624552d..cad79c2 100644
+--- a/base/gsmalloc.c
++++ b/base/gsmalloc.c
+@@ -178,7 +178,7 @@ gs_heap_alloc_bytes(gs_memory_t * mem, uint size, client_name_t cname)
+     } else {
+         uint added = size + sizeof(gs_malloc_block_t);
+ 
+-        if (mmem->limit - added < mmem->used)
++        if (added <= size || mmem->limit - added < mmem->used)
+             set_msg("exceeded limit");
+         else if ((ptr = (byte *) Memento_label(malloc(added), cname)) == 0)
+             set_msg("failed");
+-- 
+2.4.6
+