libxml2: CVE-2017-5969

Fixes a NULL pointer dereference in libxml2, when using
xmllint --recover. A maliciously crafted file, when parsed
in recovery mode, could cause the application to crash.

Reference
https://bugzilla.gnome.org/show_bug.cgi?id=778519

Signed-off-by: Sona Sarmadi <sona.sarmadi@enea.com>
Signed-off-by: Adrian Dudau <adrian.dudau@enea.com>

2 files changed, 74 insertions, 0 deletions

diff --git a/recipes-core/libxml/libxml2/CVE-2017-5969.patch b/recipes-core/libxml/libxml2/CVE-2017-5969.patch
new file mode 100644
index 0000000..0c5efbe
--- /dev/null
+++ b/recipes-core/libxml/libxml2/CVE-2017-5969.patch
@@ -0,0 +1,68 @@
+From 94691dc884d1a8ada39f073408b4bb92fe7fe882 Mon Sep 17 00:00:00 2001
+From: Daniel Veillard <veillard@redhat.com>
+Date: Wed, 7 Jun 2017 16:47:36 +0200
+Subject: [PATCH] Fix NULL pointer deref in xmlDumpElementContent
+
+Can only be triggered in recovery mode.
+
+Fixes bug 758422 (CVE-2017-5969).
+
+CVE: CVE-2017-5969
+Upstream-Status: Backport
+
+Signed-off-by: Sona Sarmadi <sona.sarmadi@enea.com>
+---
+ valid.c | 24 ++++++++++++++----------
+ 1 file changed, 14 insertions(+), 10 deletions(-)
+
+diff --git a/valid.c b/valid.c
+index 9b2df56..8075d3a 100644
+--- a/valid.c
++++ b/valid.c
+@@ -1172,29 +1172,33 @@ xmlDumpElementContent(xmlBufferPtr buf, xmlElementContentPtr content, int glob)
+            xmlBufferWriteCHAR(buf, content->name);
+            break;
+        case XML_ELEMENT_CONTENT_SEQ:
+-           if ((content->c1->type == XML_ELEMENT_CONTENT_OR) ||
+-               (content->c1->type == XML_ELEMENT_CONTENT_SEQ))
++           if ((content->c1 != NULL) &&
++               ((content->c1->type == XML_ELEMENT_CONTENT_OR) ||
++                (content->c1->type == XML_ELEMENT_CONTENT_SEQ)))
+                xmlDumpElementContent(buf, content->c1, 1);
+            else
+                xmlDumpElementContent(buf, content->c1, 0);
+             xmlBufferWriteChar(buf, " , ");
+-           if ((content->c2->type == XML_ELEMENT_CONTENT_OR) ||
+-               ((content->c2->type == XML_ELEMENT_CONTENT_SEQ) &&
+-                (content->c2->ocur != XML_ELEMENT_CONTENT_ONCE)))
++           if ((content->c2 != NULL) &&
++               ((content->c2->type == XML_ELEMENT_CONTENT_OR) ||
++                ((content->c2->type == XML_ELEMENT_CONTENT_SEQ) &&
++                 (content->c2->ocur != XML_ELEMENT_CONTENT_ONCE))))
+                xmlDumpElementContent(buf, content->c2, 1);
+            else
+                xmlDumpElementContent(buf, content->c2, 0);
+            break;
+        case XML_ELEMENT_CONTENT_OR:
+-           if ((content->c1->type == XML_ELEMENT_CONTENT_OR) ||
+-               (content->c1->type == XML_ELEMENT_CONTENT_SEQ))
++           if ((content->c1 != NULL) &&
++               ((content->c1->type == XML_ELEMENT_CONTENT_OR) ||
++                (content->c1->type == XML_ELEMENT_CONTENT_SEQ)))
+                xmlDumpElementContent(buf, content->c1, 1);
+            else
+                xmlDumpElementContent(buf, content->c1, 0);
+             xmlBufferWriteChar(buf, " | ");
+-           if ((content->c2->type == XML_ELEMENT_CONTENT_SEQ) ||
+-               ((content->c2->type == XML_ELEMENT_CONTENT_OR) &&
+-                (content->c2->ocur != XML_ELEMENT_CONTENT_ONCE)))
++           if ((content->c2 != NULL) &&
++               ((content->c2->type == XML_ELEMENT_CONTENT_SEQ) ||
++                ((content->c2->type == XML_ELEMENT_CONTENT_OR) &&
++                 (content->c2->ocur != XML_ELEMENT_CONTENT_ONCE))))
+                xmlDumpElementContent(buf, content->c2, 1);
+            else
+                xmlDumpElementContent(buf, content->c2, 0);
+-- 
+1.9.1
+
diff --git a/recipes-core/libxml/libxml2_%.bbappend b/recipes-core/libxml/libxml2_%.bbappend
new file mode 100644
index 0000000..271f582
--- /dev/null
+++ b/recipes-core/libxml/libxml2_%.bbappend
@@ -0,0 +1,6 @@
+# look for files in the layer first
+FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
+
+SRC_URI += "file://CVE-2017-5969.patch \
+           "
+