libxml2: security fix CVE-2015-7498

(From OE-Core rev: b3d6a714180199a5e0099e3d40b37c9bfa106eb1)

Signed-off-by: Armin Kuster <akuster@mvista.com>
Signed-off-by: Joshua Lock <joshua.g.lock@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 90 insertions, 0 deletions

diff --git a/meta/recipes-core/libxml/libxml2.inc b/meta/recipes-core/libxml/libxml2.inc
index 365d5bc..759f722 100644
--- a/meta/recipes-core/libxml/libxml2.inc
+++ b/meta/recipes-core/libxml/libxml2.inc
@@ -29,6 +29,7 @@ SRC_URI = "ftp://xmlsoft.org/libxml2/libxml2-${PV}.tar.gz;name=libtar \
            file://CVE-2015-7942-Another-variation-of-overflow-in-Conditional-section.patch \
            file://CVE-2015-7942-2-Fix-an-error-in-previous-Conditional-section-patch.patch \
            file://0001-CVE-2015-8035-Fix-XZ-compression-support-loop.patch \
+           file://CVE-2015-7498-Avoid-processing-entities-after-encoding-conversion-.patch \
           "
 
 BINCONFIG = "${bindir}/xml2-config"
diff --git a/meta/recipes-core/libxml/libxml2/CVE-2015-7498-Avoid-processing-entities-after-encoding-conversion-.patch b/meta/recipes-core/libxml/libxml2/CVE-2015-7498-Avoid-processing-entities-after-encoding-conversion-.patch
new file mode 100644
index 0000000..47ba897
--- /dev/null
+++ b/meta/recipes-core/libxml/libxml2/CVE-2015-7498-Avoid-processing-entities-after-encoding-conversion-.patch
@@ -0,0 +1,89 @@
+From afd27c21f6b36e22682b7da20d726bce2dcb2f43 Mon Sep 17 00:00:00 2001
+From: Daniel Veillard <veillard@redhat.com>
+Date: Mon, 9 Nov 2015 18:07:18 +0800
+Subject: [PATCH] Avoid processing entities after encoding conversion failures
+
+For https://bugzilla.gnome.org/show_bug.cgi?id=756527
+and was also raised by Chromium team in the past
+
+When we hit a convwersion failure when switching encoding
+it is bestter to stop parsing there, this was treated as a
+fatal error but the parser was continuing to process to extract
+more errors, unfortunately that makes little sense as the data
+is obviously corrupt and can potentially lead to unexpected behaviour.
+
+Upstream-Status: Backport
+
+CVE-2015-7498
+
+Signed-off-by: Armin Kuster <akuster@mvista.com>
+
+---
+ parser.c          |  7 +++++--
+ parserInternals.c | 11 ++++++++++-
+ 2 files changed, 15 insertions(+), 3 deletions(-)
+
+diff --git a/parser.c b/parser.c
+index 134afe7..c79b4e8 100644
+--- a/parser.c
++++ b/parser.c
+@@ -10665,7 +10665,8 @@ xmlParseXMLDecl(xmlParserCtxtPtr ctxt) {
+ 	xmlFatalErrMsg(ctxt, XML_ERR_SPACE_REQUIRED, "Blank needed here\n");
+     }
+     xmlParseEncodingDecl(ctxt);
+-    if (ctxt->errNo == XML_ERR_UNSUPPORTED_ENCODING) {
++    if ((ctxt->errNo == XML_ERR_UNSUPPORTED_ENCODING) ||
++         (ctxt->instate == XML_PARSER_EOF)) {
+ 	/*
+ 	 * The XML REC instructs us to stop parsing right here
+ 	 */
+@@ -10789,6 +10790,7 @@ xmlParseDocument(xmlParserCtxtPtr ctxt) {
+ 
+     if (CUR == 0) {
+ 	xmlFatalErr(ctxt, XML_ERR_DOCUMENT_EMPTY, NULL);
++	return(-1);
+     }
+ 
+     /*
+@@ -10806,7 +10808,8 @@ xmlParseDocument(xmlParserCtxtPtr ctxt) {
+ 	 * Note that we will switch encoding on the fly.
+ 	 */
+ 	xmlParseXMLDecl(ctxt);
+-	if (ctxt->errNo == XML_ERR_UNSUPPORTED_ENCODING) {
++	if ((ctxt->errNo == XML_ERR_UNSUPPORTED_ENCODING) ||
++	    (ctxt->instate == XML_PARSER_EOF)) {
+ 	    /*
+ 	     * The XML REC instructs us to stop parsing right here
+ 	     */
+diff --git a/parserInternals.c b/parserInternals.c
+index df204fd..c8230c1 100644
+--- a/parserInternals.c
++++ b/parserInternals.c
+@@ -937,6 +937,7 @@ xmlSwitchEncoding(xmlParserCtxtPtr ctxt, xmlCharEncoding enc)
+ {
+     xmlCharEncodingHandlerPtr handler;
+     int len = -1;
++    int ret;
+ 
+     if (ctxt == NULL) return(-1);
+     switch (enc) {
+@@ -1097,7 +1098,15 @@ xmlSwitchEncoding(xmlParserCtxtPtr ctxt, xmlCharEncoding enc)
+     if (handler == NULL)
+ 	return(-1);
+     ctxt->charset = XML_CHAR_ENCODING_UTF8;
+-    return(xmlSwitchToEncodingInt(ctxt, handler, len));
++    ret = xmlSwitchToEncodingInt(ctxt, handler, len);
++    if ((ret < 0) || (ctxt->errNo == XML_I18N_CONV_FAILED)) {
++        /*
++	 * on encoding conversion errors, stop the parser
++	 */
++        xmlStopParser(ctxt);
++	ctxt->errNo = XML_I18N_CONV_FAILED;
++    }
++    return(ret);
+ }
+ 
+ /**
+-- 
+2.3.5
+