From 00906759053986b8079985644172085f74331f83 Mon Sep 17 00:00:00 2001
From: David Kilzer <ddkilzer@apple.com>
Date: Tue, 26 Jan 2016 16:57:03 -0800
Subject: [PATCH] Heap-based buffer-underreads due to xmlParseName

For https://bugzilla.gnome.org/show_bug.cgi?id=759573

* parser.c:
(xmlParseElementDecl): Return early on invalid input to fix
non-minimized test case (759573-2.xml).  Otherwise the parser
gets into a bad state in SKIP(3) at the end of the function.
(xmlParseConditionalSections): Halt parsing when hitting invalid
input that would otherwise caused xmlParserHandlePEReference()
to recurse unexpectedly.  This fixes the minimized test case
(759573.xml).

* result/errors/759573-2.xml: Add.
* result/errors/759573-2.xml.err: Add.
* result/errors/759573-2.xml.str: Add.
* result/errors/759573.xml: Add.
* result/errors/759573.xml.err: Add.
* result/errors/759573.xml.str: Add.
* test/errors/759573-2.xml: Add.
* test/errors/759573.xml: Add.

Upstream-Status: Backport 
CVE: CVE-2016-4447
Signed-off-by: Armin Kuster <akuster@mvist.com>

---
 parser.c                       |  2 ++
 result/errors/759573-2.xml     |  0
 result/errors/759573-2.xml.err | 58 ++++++++++++++++++++++++++++++++++++++++++
 result/errors/759573-2.xml.str |  4 +++
 result/errors/759573.xml       |  0
 result/errors/759573.xml.err   | 31 ++++++++++++++++++++++
 result/errors/759573.xml.str   |  4 +++
 test/errors/759573-2.xml       |  9 +++++++
 test/errors/759573.xml         |  1 +
 9 files changed, 109 insertions(+)
 create mode 100644 result/errors/759573-2.xml
 create mode 100644 result/errors/759573-2.xml.err
 create mode 100644 result/errors/759573-2.xml.str
 create mode 100644 result/errors/759573.xml
 create mode 100644 result/errors/759573.xml.err
 create mode 100644 result/errors/759573.xml.str
 create mode 100644 test/errors/759573-2.xml
 create mode 100644 test/errors/759573.xml

Index: libxml2-2.9.2/parser.c
===================================================================
--- libxml2-2.9.2.orig/parser.c
+++ libxml2-2.9.2/parser.c
@@ -6723,6 +6723,7 @@ xmlParseElementDecl(xmlParserCtxtPtr ctx
 	if (!IS_BLANK_CH(CUR)) {
 	    xmlFatalErrMsg(ctxt, XML_ERR_SPACE_REQUIRED,
 		           "Space required after 'ELEMENT'\n");
+	    return(-1);
 	}
         SKIP_BLANKS;
         name = xmlParseName(ctxt);
@@ -6874,6 +6875,7 @@ xmlParseConditionalSections(xmlParserCtx
 
 	    if ((CUR_PTR == check) && (cons == ctxt->input->consumed)) {
 		xmlFatalErr(ctxt, XML_ERR_EXT_SUBSET_NOT_FINISHED, NULL);
+		xmlHaltParser(ctxt);
 		break;
 	    }
 	}
Index: libxml2-2.9.2/result/errors/759573-2.xml.err
===================================================================
--- /dev/null
+++ libxml2-2.9.2/result/errors/759573-2.xml.err
@@ -0,0 +1,58 @@
+Entity: line 1: parser error : Space required after '<!ENTITY'
+ %zz;
+     ^
+Entity: line 1:
+<!ENTITY<?xDOCTYPEm~?>
+        ^
+Entity: line 1: parser error : xmlParseEntityDecl: no name
+ %zz;
+     ^
+Entity: line 1:
+<!ENTITY<?xDOCTYPEm~?>
+        ^
+Entity: line 1: parser error : ParsePI: PI xDOCTYPEm space expected
+ %zz;
+     ^
+Entity: line 1:
+<!ENTITY<?xDOCTYPEm~?>
+                   ^
+Entity: line 1: parser error : Space required after '<!ENTITY'
+ %zz;
+     ^
+Entity: line 1:
+<!ENTITY<?xDOCTYPEm~?>
+        ^
+Entity: line 1: parser error : xmlParseEntityDecl: no name
+ %zz;
+     ^
+Entity: line 1:
+<!ENTITY<?xDOCTYPEm~?>
+        ^
+Entity: line 1: parser error : ParsePI: PI xDOCTYPEm space expected
+ %zz;
+     ^
+Entity: line 1:
+<!ENTITY<?xDOCTYPEm~?>
+                   ^
+Entity: line 1: parser error : Space required after 'ELEMENT'
+ %xx;
+     ^
+Entity: line 3:
+%zz;<!ELEMENTD(%MENT%MENTDŹMENTD%zNMT9KENSMYSYSTEM;MENT9%zz;
+             ^
+Entity: line 1: parser error : Content error in the external subset
+ %xx;
+     ^
+Entity: line 3:
+%zz;<!ELEMENTD(%MENT%MENTDŹMENTD%zNMT9KENSMYSYSTEM;MENT9%zz;
+             ^
+./test/errors/759573-2.xml:6: parser error : internal error: xmlParseInternalSubset: error detected in Markup declaration
+
+%xx;ÿggKENSMYNT&#35;MENTD&#372zz;'>
+    ^
+./test/errors/759573-2.xml:6: parser error : DOCTYPE improperly terminated
+%xx;ÿggKENSMYNT&#35;MENTD&#372zz;'>
+    ^
+./test/errors/759573-2.xml:6: parser error : Start tag expected, '<' not found
+%xx;ÿggKENSMYNT&#35;MENTD&#372zz;'>
+    ^
Index: libxml2-2.9.2/result/errors/759573-2.xml.str
===================================================================
--- /dev/null
+++ libxml2-2.9.2/result/errors/759573-2.xml.str
@@ -0,0 +1,4 @@
+./test/errors/759573-2.xml:2: parser error : Extra content at the end of the document
+<!DOCTYPE test [
+               ^
+./test/errors/759573-2.xml : failed to parse
Index: libxml2-2.9.2/result/errors/759573.xml.err
===================================================================
--- /dev/null
+++ libxml2-2.9.2/result/errors/759573.xml.err
@@ -0,0 +1,31 @@
+./test/errors/759573.xml:1: parser error : Space required after '<!ENTITY'
+ELEMENT t (A)><!ENTITY % xx '&#37;<![INCLUDE[000&#37;&#3000;000&#37;z;'><!ENTITY
+                                                                               ^
+./test/errors/759573.xml:1: parser error : Space required after the entity name
+LEMENT t (A)><!ENTITY % xx '&#37;<![INCLUDE[000&#37;&#3000;000&#37;z;'><!ENTITYz
+                                                                               ^
+./test/errors/759573.xml:1: parser error : Entity value required
+LEMENT t (A)><!ENTITY % xx '&#37;<![INCLUDE[000&#37;&#3000;000&#37;z;'><!ENTITYz
+                                                                               ^
+Entity: line 1: parser error : PEReference: no name
+ %xx;
+     ^
+Entity: line 1:
+%<![INCLUDE[000%ஸ000%z;
+ ^
+Entity: line 1: parser error : Content error in the external subset
+ %xx;
+     ^
+Entity: line 1:
+%<![INCLUDE[000%ஸ000%z;
+            ^
+./test/errors/759573.xml:1: parser error : internal error: xmlParseInternalSubset: error detected in Markup declaration
+
+T t (A)><!ENTITY % xx '&#37;<![INCLUDE[000&#37;&#3000;000&#37;z;'><!ENTITYz>%xx;
+                                                                               ^
+./test/errors/759573.xml:1: parser error : DOCTYPE improperly terminated
+T t (A)><!ENTITY % xx '&#37;<![INCLUDE[000&#37;&#3000;000&#37;z;'><!ENTITYz>%xx;
+                                                                               ^
+./test/errors/759573.xml:1: parser error : Start tag expected, '<' not found
+T t (A)><!ENTITY % xx '&#37;<![INCLUDE[000&#37;&#3000;000&#37;z;'><!ENTITYz>%xx;
+                                                                               ^
Index: libxml2-2.9.2/result/errors/759573.xml.str
===================================================================
--- /dev/null
+++ libxml2-2.9.2/result/errors/759573.xml.str
@@ -0,0 +1,4 @@
+./test/errors/759573.xml:1: parser error : Extra content at the end of the document
+<?h?><!DOCTYPEt[<!ELEMENT t (A)><!ENTITY % xx '&#37;<![INCLUDE[000&#37;&#3000;00
+               ^
+./test/errors/759573.xml : failed to parse
Index: libxml2-2.9.2/test/errors/759573-2.xml
===================================================================
--- /dev/null
+++ libxml2-2.9.2/test/errors/759573-2.xml
@@ -0,0 +1,9 @@
+<?xmh ven="1.0"?>
+<!DOCTYPE test [
+<!ELEMENT test (#PCDATA) >
+<!ENTITY % xx '&#37;zz;
<![INCLUDE[
&#37;zz;<!ELEMENTD(&#37;MENT&#37;MENTD&#377;MENTD&#37;zNMT9KENSMYSYSTEM;MENT9&#37;zz;'>
+<!ENTITY % zz '&#60;!ENTITY<?xDOCTYPEm~?>' >
+%xx;ÿggKENSMYNT&#35;MENTD&#372zz;'>
+<!ENBITY % zz '&#60;!EN#3&##37;z ';!EY'#x;g
+<!ENTent ref="bè:b>r.B"/>
+e		</
\ No newline at end of file
Index: libxml2-2.9.2/test/errors/759573.xml
===================================================================
--- /dev/null
+++ libxml2-2.9.2/test/errors/759573.xml
@@ -0,0 +1 @@
+<?h?><!DOCTYPEt[<!ELEMENT t (A)><!ENTITY % xx '&#37;<![INCLUDE[000&#37;&#3000;000&#37;z;'><!ENTITYz>%xx;
\ No newline at end of file