package/taglib: fix CVE-2017-12678

In TagLib 1.11.1, the rebuildAggregateFrames function in
id3v2framefactory.cpp has a pointer to cast vulnerability, which allows
remote attackers to cause a denial of service or possibly have
unspecified other impact via a crafted audio file.

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/taglib/0002-Don-t-assume-TDRC-is-an-instance-of-TextIdentificationFrame.patch

@@ -0,0 +1,33 @@
+From eb9ded1206f18f2c319157337edea2533a40bea6 Mon Sep 17 00:00:00 2001
+From: "Stephen F. Booth" <me@sbooth.org>
+Date: Sun, 23 Jul 2017 10:11:09 -0400
+Subject: [PATCH] Don't assume TDRC is an instance of TextIdentificationFrame
+
+If TDRC is encrypted, FrameFactory::createFrame() returns UnknownFrame
+which causes problems in rebuildAggregateFrames() when it is assumed
+that TDRC is a TextIdentificationFrame
+[Retrieved from:
+https://github.com/taglib/taglib/pull/831/commits/eb9ded1206f18f2c319157337edea2533a40bea6]
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+---
+ taglib/mpeg/id3v2/id3v2framefactory.cpp | 5 +++--
+ 1 file changed, 3 insertions(+), 2 deletions(-)
+
+diff --git a/taglib/mpeg/id3v2/id3v2framefactory.cpp b/taglib/mpeg/id3v2/id3v2framefactory.cpp
+index 759a9b7be..9347ab869 100644
+--- a/taglib/mpeg/id3v2/id3v2framefactory.cpp
++++ b/taglib/mpeg/id3v2/id3v2framefactory.cpp
+@@ -334,10 +334,11 @@ void FrameFactory::rebuildAggregateFrames(ID3v2::Tag *tag) const
+      tag->frameList("TDAT").size() == 1)
+   {
+     TextIdentificationFrame *tdrc =
+-      static_cast<TextIdentificationFrame *>(tag->frameList("TDRC").front());
++      dynamic_cast<TextIdentificationFrame *>(tag->frameList("TDRC").front());
+     UnknownFrame *tdat = static_cast<UnknownFrame *>(tag->frameList("TDAT").front());
+ 
+-    if(tdrc->fieldList().size() == 1 &&
++    if(tdrc &&
++       tdrc->fieldList().size() == 1 &&
+        tdrc->fieldList().front().size() == 4 &&
+        tdat->data().size() >= 5)
+     {

package/taglib/taglib.mk

@@ -10,6 +10,9 @@ TAGLIB_INSTALL_STAGING = YES
 TAGLIB_LICENSE = LGPL-2.1 or MPL-1.1
 TAGLIB_LICENSE_FILES = COPYING.LGPL COPYING.MPL
 
+# 0002-Don-t-assume-TDRC-is-an-instance-of-TextIdentificationFrame.patch
+TAGLIB_IGNORE_CVES += CVE-2017-12678
+
 ifeq ($(BR2_PACKAGE_ZLIB),y)
 TAGLIB_DEPENDENCIES += zlib
 endif