libvorbis: add patch for CVE-2017-14632 and CVE-2017-14633

Signed-off-by: Ted Hess <thess@kitschensync.net>

libs/libvorbis/Makefile

@@ -1,6 +1,4 @@
 #
-# Copyright (C) 2008-2015 OpenWrt.org
-#
 # This is free software, licensed under the GNU General Public License v2.
 # See /LICENSE for more information.
 #
@@ -9,7 +7,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=libvorbis
 PKG_VERSION:=1.3.5
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=http://downloads.xiph.org/releases/vorbis/

libs/libvorbis/patches/100-CVE-2017-14632-CVE-2017-14633.patch

@@ -0,0 +1,12 @@
+--- a/lib/info.c
++++ b/lib/info.c
+@@ -583,7 +583,8 @@ int vorbis_analysis_headerout(vorbis_dsp
+   oggpack_buffer opb;
+   private_state *b=v->backend_state;
+ 
+-  if(!b||vi->channels<=0){
++  if(!b||vi->channels<=0||vi->channels>255){
++    b = NULL;
+     ret=OV_EFAULT;
+     goto err_out;
+   }