gnu: flac: Fix CVE-2017-6888.

* gnu/packages/xiph.scm (flac)[replacement]: New field.
(flac/fixed): New variable.
* gnu/packages/patches/flac-CVE-2017-6888.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.

gnu/local.mk

@@ -771,6 +771,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/findutils-localstatedir.patch		\
   %D%/packages/patches/findutils-makedev.patch			\
   %D%/packages/patches/findutils-test-xargs.patch		\
+  %D%/packages/patches/flac-CVE-2017-6888.patch		\
   %D%/packages/patches/flann-cmake-3.11.patch			\
   %D%/packages/patches/flint-ldconfig.patch			\
   %D%/packages/patches/foomatic-filters-CVE-2015-8327.patch	\

gnu/packages/patches/flac-CVE-2017-6888.patch

@@ -0,0 +1,29 @@
+https://git.xiph.org/?p=flac.git;a=patch;h=4f47b63e9c971e6391590caf00a0f2a5ed612e67
+
+From 4f47b63e9c971e6391590caf00a0f2a5ed612e67 Mon Sep 17 00:00:00 2001
+From: Erik de Castro Lopo <erikd@mega-nerd.com>
+Date: Sat, 8 Apr 2017 18:34:49 +1000
+Subject: [PATCH] stream_decoder.c: Fix a memory leak
+
+Leak reported by Secunia Research.
+---
+ src/libFLAC/stream_decoder.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/src/libFLAC/stream_decoder.c b/src/libFLAC/stream_decoder.c
+index 14d5fe7f..a5527511 100644
+--- a/src/libFLAC/stream_decoder.c
++++ b/src/libFLAC/stream_decoder.c
+@@ -1753,6 +1753,9 @@ FLAC__bool read_metadata_vorbiscomment_(FLAC__StreamDecoder *decoder, FLAC__Stre
+ 					}
+ 					memset (obj->comments[i].entry, 0, obj->comments[i].length) ;
+ 					if (!FLAC__bitreader_read_byte_block_aligned_no_crc(decoder->private_->input, obj->comments[i].entry, obj->comments[i].length)) {
++						/* Current i-th entry is bad, so we delete it. */
++						free (obj->comments[i].entry) ;
++						obj->comments[i].entry = NULL ;
+ 						obj->num_comments = i;
+ 						goto skip;
+ 					}
+-- 
+2.11.0
+

gnu/packages/xiph.scm

@@ -5,7 +5,7 @@
 ;;; Copyright © 2014 Sree Harsha Totakura <sreeharsha@totakura.in>
 ;;; Copyright © 2014 Mark H Weaver <mhw@netris.org>
 ;;; Copyright © 2015 Paul van der Walt <paul@denknerd.org>
-;;; Copyright © 2015, 2016, 2017 Efraim Flashner <efraim@flashner.co.il>
+;;; Copyright © 2015, 2016, 2017, 2019 Efraim Flashner <efraim@flashner.co.il>
 ;;; Copyright © 2017, 2018 Marius Bakke <mbakke@fastmail.com>
 ;;; Copyright © 2018 Tobias Geerinckx-Rice <me@tobias.gr>
 ;;; Copyright © 2018 Leo Famulari <leo@famulari.name>
@@ -235,6 +235,7 @@ It currently supports:
 (define flac
   (package
    (name "flac")
+   (replacement flac/fixed)
    (version "1.3.2")
    (source (origin
             (method url-fetch)
@@ -256,6 +257,14 @@ meaning that audio is compressed in FLAC without any loss in quality.")
                                "See COPYING in the distribution.")) ; and LGPL and GPL
    (home-page "https://xiph.org/flac/")))
 
+(define flac/fixed
+  (package
+    (inherit flac)
+    (source
+      (origin
+        (inherit (package-source flac))
+        (patches (search-patches "flac-CVE-2017-6888.patch"))))))
+
 (define libkate
   (package
    (name "libkate")