[Buildroot] [PATCH] package/libxml2: add upstream security fix for CVE-2019-20388

[Thomas De Schampheleire <patrickdepinguin@gmail.com>]

From: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>

Fixes CVE-2019-20388: xmlSchemaPreRun in xmlschemas.c in libxml2 2.9.10
allows an xmlSchemaValidateStream memory leak.

Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
---
 ...mory-leak-in-xmlSchemaValidateStream.patch | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 package/libxml2/0002-Fix-memory-leak-in-xmlSchemaValidateStream.patch

diff --git a/package/libxml2/0002-Fix-memory-leak-in-xmlSchemaValidateStream.patch b/package/libxml2/0002-Fix-memory-leak-in-xmlSchemaValidateStream.patch
new file mode 100644
index 0000000000..49ff6fbe00
--- /dev/null
+++ b/package/libxml2/0002-Fix-memory-leak-in-xmlSchemaValidateStream.patch
@@ -0,0 +1,33 @@
+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.
+
+Signed-off-by: Zhipeng Xie <xiezhipeng1@huawei.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
+
-- 
2.24.1