libxml2: Fix CVE-2019-20388

see:
https://gitlab.gnome.org/GNOME/libxml2/merge_requests/68

(From OE-Core rev: 6c4477563bc418ec215671d6960e6e8d6bdd074b)

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

meta/recipes-core/libxml/libxml2/CVE-2019-20388.patch

@@ -0,0 +1,37 @@
+From 7ffcd44d7e6c46704f8af0321d9314cd26e0e18a Mon Sep 17 00:00:00 2001
+From: Zhipeng Xie <xiezhipeng1@huawei.com>
+Date: Tue, 20 Aug 2019 16:33:06 +0800
+Subject: [PATCH] Fix memory leak in xmlSchemaValidateStream
+
+When ctxt->schema is NULL, xmlSchemaSAXPlug->xmlSchemaPreRun
+alloc a new schema for ctxt->schema and set vctxt->xsiAssemble
+to 1. Then xmlSchemaVStart->xmlSchemaPreRun initialize
+vctxt->xsiAssemble to 0 again which cause the alloced schema
+can not be freed anymore.
+
+Found with libFuzzer.
+
+Upstream-Status: Accepted [https://gitlab.gnome.org/GNOME/libxml2/commit/7ffcd44d7e6c46704f8af0321d9314cd26e0e18a]
+CVE: CVE-2019-20388
+
+Signed-off-by: Zhipeng Xie <xiezhipeng1@huawei.com>
+Signed-off-by: Lee Chee Yang <chee.yang.lee@intel.com>
+---
+ xmlschemas.c | 1 -
+ 1 file changed, 1 deletion(-)
+
+diff --git a/xmlschemas.c b/xmlschemas.c
+index 301c8449..39d92182 100644
+--- a/xmlschemas.c
++++ b/xmlschemas.c
+@@ -28090,7 +28090,6 @@ xmlSchemaPreRun(xmlSchemaValidCtxtPtr vctxt) {
+     vctxt->nberrors = 0;
+     vctxt->depth = -1;
+     vctxt->skipDepth = -1;
+-    vctxt->xsiAssemble = 0;
+     vctxt->hasKeyrefs = 0;
+ #ifdef ENABLE_IDC_NODE_TABLES_TEST
+     vctxt->createIDCNodeTables = 1;
+-- 
+2.24.1
+

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

@@ -25,6 +25,7 @@ SRC_URI = "http://www.xmlsoft.org/sources/libxml2-${PV}.tar.gz;name=libtar \
            file://0001-Fix-infinite-loop-in-LZMA-decompression.patch \
            file://fix-CVE-2019-19956.patch \
            file://CVE-2020-7595.patch \
+           file://CVE-2019-20388.patch \
            "
 
 SRC_URI[libtar.md5sum] = "b786e353e2aa1b872d70d5d1ca0c740d"