gnu: vorbis-tools: Patch buffer overflow [fixes CVE-2015-6749].

* gnu/packages/patches/vorbis-tools-CVE-2015-6749.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/xiph.scm (vorbis-tools)[source]: Use it.

gnu-system.am

@@ -770,6 +770,7 @@ dist_patch_DATA =						\
   gnu/packages/patches/util-linux-tests.patch			\
   gnu/packages/patches/upower-builddir.patch			\
   gnu/packages/patches/valgrind-enable-arm.patch		\
+  gnu/packages/patches/vorbis-tools-CVE-2015-6749.patch		\
   gnu/packages/patches/vpnc-script.patch			\
   gnu/packages/patches/vtk-mesa-10.patch			\
   gnu/packages/patches/w3m-libgc.patch				\

gnu/packages/patches/vorbis-tools-CVE-2015-6749.patch

+Upstream fix for CVE-2015-6749.
+https://trac.xiph.org/ticket/2212
+
+From 04815d3e1bfae3a6cdfb2c25358a5a72b61299f7 Mon Sep 17 00:00:00 2001
+From: Mark Harris <mark.hsj@gmail.com>
+Date: Sun, 30 Aug 2015 05:54:46 -0700
+Subject: [PATCH] oggenc: Fix large alloca on bad AIFF input
+
+Fixes #2212
+---
+ oggenc/audio.c | 10 +++++-----
+ 1 file changed, 5 insertions(+), 5 deletions(-)
+
+diff --git a/oggenc/audio.c b/oggenc/audio.c
+index 477da8c..4921fb9 100644
+--- a/oggenc/audio.c
++++ b/oggenc/audio.c
+@@ -245,8 +245,8 @@ static int aiff_permute_matrix[6][6] =
+ int aiff_open(FILE *in, oe_enc_opt *opt, unsigned char *buf, int buflen)
+ {
+     int aifc; /* AIFC or AIFF? */
+-    unsigned int len;
+-    unsigned char *buffer;
++    unsigned int len, readlen;
++    unsigned char buffer[22];
+     unsigned char buf2[8];
+     aiff_fmt format;
+     aifffile *aiff = malloc(sizeof(aifffile));
+@@ -269,9 +269,9 @@ int aiff_open(FILE *in, oe_enc_opt *opt, unsigned char *buf, int buflen)
+         return 0; /* Weird common chunk */
+     }
+ 
+-    buffer = alloca(len);
+-
+-    if(fread(buffer,1,len,in) < len)
++    readlen = len < sizeof(buffer) ? len : sizeof(buffer);
++    if(fread(buffer,1,readlen,in) < readlen ||
++       (len > readlen && !seek_forward(in, len-readlen)))
+     {
+         fprintf(stderr, _("Warning: Unexpected EOF in reading AIFF header\n"));
+         return 0;
+-- 
+2.5.0
+

gnu/packages/xiph.scm

@@ -266,7 +266,8 @@ (define vorbis-tools
                                 "vorbis-tools-" version ".tar.gz"))
             (sha256
              (base32
-              "1g12bnh5ah08v529y72kfdz5lhvy75iaz7f9jskyby23m9dkk2d3"))))
+              "1g12bnh5ah08v529y72kfdz5lhvy75iaz7f9jskyby23m9dkk2d3"))
+            (patches (list (search-patch "vorbis-tools-CVE-2015-6749.patch")))))
    (build-system gnu-build-system)
    (inputs `(("ao" ,ao)
              ("curl" ,curl)