libxml2: Fix CVE-2019-19956

(From OE-Core rev: 2be6ab4249c4f49c9ffcd9bb8fea964c8c5d449c)

Signed-off-by: Rahul Chauhan <rahulk@mvista.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 +1,38 @@
+From 3cd2b25ddb04740be2880cfd78d60038452228b1 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: Rahul Chauhan <rahulk@mvista.com>
+---
+ parser.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/parser.c b/parser.c
+index b7ecd65..491f5c9 100644
+--- a/parser.c
++++ b/parser.c
+@@ -13899,7 +13899,8 @@ 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);
+-- 
+2.7.4
+

meta/recipes-core/libxml/libxml2_2.9.8.bb

@@ -23,6 +23,7 @@ SRC_URI = "http://www.xmlsoft.org/sources/libxml2-${PV}.tar.gz;name=libtar \
            file://fix-CVE-2017-8872.patch \
            file://fix-CVE-2018-14404.patch \
            file://0001-Fix-infinite-loop-in-LZMA-decompression.patch \
+           file://fix-CVE-2019-19956.patch \
            "
 
 SRC_URI[libtar.md5sum] = "b786e353e2aa1b872d70d5d1ca0c740d"