libxml2: Fix CVE-2019-19956

see:
5a02583c7e

(From OE-Core rev: 9fd363d21df59fff4488763d62548c936b4d14fb)

Signed-off-by: Lee Chee Yang <chee.yang.lee@intel.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/libxml/libxml2/Fix-CVE-2019-19956.patch

@@ -0,0 +1,40 @@
+From 5a02583c7e683896d84878bd90641d8d9b0d0549 Mon Sep 17 00:00:00 2001
+From: Zhipeng Xie <xiezhipeng1@huawei.com>
+Date: Wed, 7 Aug 2019 17:39:17 +0800
+Subject: [PATCH] Fix memory leak in xmlParseBalancedChunkMemoryRecover
+
+When doc is NULL, namespace created in xmlTreeEnsureXMLDecl
+is bind to newDoc->oldNs, in this case, set newDoc->oldNs to
+NULL and free newDoc will cause a memory leak.
+
+Found with libFuzzer.
+
+Closes #82.
+
+Upstream-Status: Backport [https://gitlab.gnome.org/GNOME/libxml2/commit/5a02583c7e683896d84878bd90641d8d9b0d0549]
+CVE: CVE-2019-19956
+
+Signed-off-by: Chee Yang Lee <chee.yang.lee@intel.com>
+
+---
+ parser.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/parser.c b/parser.c
+index 1ce1ccf1..26d9f4e3 100644
+--- a/parser.c
++++ b/parser.c
+@@ -13894,7 +13894,8 @@ xmlParseBalancedChunkMemoryRecover(xmlDocPtr doc, xmlSAXHandlerPtr sax,
+     xmlFreeParserCtxt(ctxt);
+     newDoc->intSubset = NULL;
+     newDoc->extSubset = NULL;
+-    newDoc->oldNs = NULL;
++    if(doc != NULL)
++	newDoc->oldNs = NULL;
+     xmlFreeDoc(newDoc);
+ 
+     return(ret);
+-- 
+2.24.1
+
+

meta/recipes-core/libxml/libxml2_2.9.9.bb

@@ -20,6 +20,7 @@ SRC_URI = "http://www.xmlsoft.org/sources/libxml2-${PV}.tar.gz;name=libtar \
            file://libxml-m4-use-pkgconfig.patch \
            file://0001-Make-ptest-run-the-python-tests-if-python-is-enabled.patch \
            file://fix-execution-of-ptests.patch \
+           file://Fix-CVE-2019-19956.patch \
            "
 
 SRC_URI[libtar.md5sum] = "c04a5a0a042eaa157e8e8c9eabe76bd6"