libxml2: CVE-2016-9318

libxml2 2.9.4 and earlier, as used in XMLSec 1.2.23 and earlier
and other products, does not offer a flag directly indicating that
the current document may be read but other files may not be opened,
which makes it easier for remote attackers to conduct XML External
Entity (XXE) attacks via a crafted document.

Reference:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-9318

Upstream patch:
https://git.gnome.org/browse/libxml2/commit/?id=2304078555896cf1638c628f50326aeef6f0e0d0

Signed-off-by: Catalin Enache <catalin.enache@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>

2 files changed, 208 insertions, 0 deletions

diff --git a/meta/recipes-core/libxml/libxml2/CVE-2016-9318.patch b/meta/recipes-core/libxml/libxml2/CVE-2016-9318.patch
new file mode 100644
index 0000000000..3581ab83df
--- /dev/null
+++ b/meta/recipes-core/libxml/libxml2/CVE-2016-9318.patch
@@ -0,0 +1,207 @@
+From 7fa1cd31552d52d50a9101f07c816ff6dd2d9f19 Mon Sep 17 00:00:00 2001
+From: Doran Moppert <dmoppert@redhat.com>
+Date: Fri, 7 Apr 2017 16:45:56 +0200
+Subject: [PATCH] Add an XML_PARSE_NOXXE flag to block all entities loading
+ even local
+
+For https://bugzilla.gnome.org/show_bug.cgi?id=772726
+
+* include/libxml/parser.h: Add a new parser flag XML_PARSE_NOXXE
+* elfgcchack.h, xmlIO.h, xmlIO.c: associated loading routine
+* include/libxml/xmlerror.h: new error raised
+* xmllint.c: adds --noxxe flag to activate the option
+
+Upstream-Status: Backport
+CVE: CVE-2016-9318
+
+Signed-off-by: Catalin Enache <catalin.enache@windriver.com>
+---
+ elfgcchack.h              | 10 ++++++++++
+ include/libxml/parser.h   |  3 ++-
+ include/libxml/xmlIO.h    |  8 ++++++++
+ include/libxml/xmlerror.h |  1 +
+ parser.c                  |  4 ++++
+ xmlIO.c                   | 40 +++++++++++++++++++++++++++++++++++-----
+ xmllint.c                 |  5 +++++
+ 7 files changed, 65 insertions(+), 6 deletions(-)
+
+diff --git a/elfgcchack.h b/elfgcchack.h
+index 8c52884..1b81dcd 100644
+--- a/elfgcchack.h
++++ b/elfgcchack.h
+@@ -6547,6 +6547,16 @@ extern __typeof (xmlNoNetExternalEntityLoader) xmlNoNetExternalEntityLoader__int
+ #endif
+ #endif
+ 
++#ifdef bottom_xmlIO
++#undef xmlNoXxeExternalEntityLoader
++extern __typeof (xmlNoXxeExternalEntityLoader) xmlNoXxeExternalEntityLoader __attribute((alias("xmlNoXxeExternalEntityLoader__internal_alias")));
++#else
++#ifndef xmlNoXxeExternalEntityLoader
++extern __typeof (xmlNoXxeExternalEntityLoader) xmlNoXxeExternalEntityLoader__internal_alias __attribute((visibility("hidden")));
++#define xmlNoXxeExternalEntityLoader xmlNoXxeExternalEntityLoader__internal_alias
++#endif
++#endif
++
+ #ifdef bottom_tree
+ #undef xmlNodeAddContent
+ extern __typeof (xmlNodeAddContent) xmlNodeAddContent __attribute((alias("xmlNodeAddContent__internal_alias")));
+diff --git a/include/libxml/parser.h b/include/libxml/parser.h
+index 47fbec0..63ca1b9 100644
+--- a/include/libxml/parser.h
++++ b/include/libxml/parser.h
+@@ -1111,7 +1111,8 @@ typedef enum {
+     XML_PARSE_HUGE      = 1<<19,/* relax any hardcoded limit from the parser */
+     XML_PARSE_OLDSAX    = 1<<20,/* parse using SAX2 interface before 2.7.0 */
+     XML_PARSE_IGNORE_ENC= 1<<21,/* ignore internal document encoding hint */
+-    XML_PARSE_BIG_LINES = 1<<22 /* Store big lines numbers in text PSVI field */
++    XML_PARSE_BIG_LINES = 1<<22,/* Store big lines numbers in text PSVI field */
++    XML_PARSE_NOXXE	= 1<<23 /* Forbid any external entity loading */
+ } xmlParserOption;
+ 
+ XMLPUBFUN void XMLCALL
+diff --git a/include/libxml/xmlIO.h b/include/libxml/xmlIO.h
+index 3e41744..8d3fdef 100644
+--- a/include/libxml/xmlIO.h
++++ b/include/libxml/xmlIO.h
+@@ -300,6 +300,14 @@ XMLPUBFUN xmlParserInputPtr XMLCALL
+ 					 xmlParserCtxtPtr ctxt);
+ 
+ /*
++ * A predefined entity loader external entity expansion
++ */
++XMLPUBFUN xmlParserInputPtr XMLCALL
++	xmlNoXxeExternalEntityLoader	(const char *URL,
++					 const char *ID,
++					 xmlParserCtxtPtr ctxt);
++
++/*
+  * xmlNormalizeWindowsPath is obsolete, don't use it.
+  * Check xmlCanonicPath in uri.h for a better alternative.
+  */
+diff --git a/include/libxml/xmlerror.h b/include/libxml/xmlerror.h
+index 037c16d..3036062 100644
+--- a/include/libxml/xmlerror.h
++++ b/include/libxml/xmlerror.h
+@@ -470,6 +470,7 @@ typedef enum {
+     XML_IO_EADDRINUSE, /* 1554 */
+     XML_IO_EALREADY, /* 1555 */
+     XML_IO_EAFNOSUPPORT, /* 1556 */
++    XML_IO_ILLEGAL_XXE, /* 1557 */
+     XML_XINCLUDE_RECURSION=1600,
+     XML_XINCLUDE_PARSE_VALUE, /* 1601 */
+     XML_XINCLUDE_ENTITY_DEF_MISMATCH, /* 1602 */
+diff --git a/parser.c b/parser.c
+index 53a6b7f..609a270 100644
+--- a/parser.c
++++ b/parser.c
+@@ -15350,6 +15350,10 @@ xmlCtxtUseOptionsInternal(xmlParserCtxtPtr ctxt, int options, const char *encodi
+ 	ctxt->options |= XML_PARSE_NONET;
+         options -= XML_PARSE_NONET;
+     }
++    if (options & XML_PARSE_NOXXE) {
++	ctxt->options |= XML_PARSE_NOXXE;
++        options -= XML_PARSE_NOXXE;
++    }
+     if (options & XML_PARSE_COMPACT) {
+ 	ctxt->options |= XML_PARSE_COMPACT;
+         options -= XML_PARSE_COMPACT;
+diff --git a/xmlIO.c b/xmlIO.c
+index 1a79c09..304f822 100644
+--- a/xmlIO.c
++++ b/xmlIO.c
+@@ -210,6 +210,7 @@ static const char *IOerr[] = {
+     "adddress in use",		/* EADDRINUSE */
+     "already in use",		/* EALREADY */
+     "unknown address familly",	/* EAFNOSUPPORT */
++    "Attempt to load external entity %s", /* XML_IO_ILLEGAL_XXE */
+ };
+ 
+ #if defined(_WIN32) || defined (__DJGPP__) && !defined (__CYGWIN__)
+@@ -4053,13 +4054,22 @@ xmlDefaultExternalEntityLoader(const char *URL, const char *ID,
+     xmlGenericError(xmlGenericErrorContext,
+                     "xmlDefaultExternalEntityLoader(%s, xxx)\n", URL);
+ #endif
+-    if ((ctxt != NULL) && (ctxt->options & XML_PARSE_NONET)) {
++    if (ctxt != NULL) {
+         int options = ctxt->options;
+ 
+-	ctxt->options -= XML_PARSE_NONET;
+-        ret = xmlNoNetExternalEntityLoader(URL, ID, ctxt);
+-	ctxt->options = options;
+-	return(ret);
++        if (options & XML_PARSE_NOXXE) {
++            ctxt->options -= XML_PARSE_NOXXE;
++            ret = xmlNoXxeExternalEntityLoader(URL, ID, ctxt);
++            ctxt->options = options;
++            return(ret);
++        }
++ 
++        if (options & XML_PARSE_NONET) {
++            ctxt->options -= XML_PARSE_NONET;
++            ret = xmlNoNetExternalEntityLoader(URL, ID, ctxt);
++            ctxt->options = options;
++            return(ret);
++        }
+     }
+ #ifdef LIBXML_CATALOG_ENABLED
+     resource = xmlResolveResourceFromCatalog(URL, ID, ctxt);
+@@ -4160,6 +4170,13 @@ xmlNoNetExternalEntityLoader(const char *URL, const char *ID,
+     xmlParserInputPtr input = NULL;
+     xmlChar *resource = NULL;
+ 
++    if (ctxt == NULL) {
++        return(NULL);
++    }
++    if (ctxt->input_id == 1) {
++        return xmlDefaultExternalEntityLoader((const char *) URL, ID, ctxt);
++    }
++
+ #ifdef LIBXML_CATALOG_ENABLED
+     resource = xmlResolveResourceFromCatalog(URL, ID, ctxt);
+ #endif
+@@ -4182,5 +4199,18 @@ xmlNoNetExternalEntityLoader(const char *URL, const char *ID,
+     return(input);
+ }
+ 
++xmlParserInputPtr
++xmlNoXxeExternalEntityLoader(const char *URL, const char *ID,
++                          xmlParserCtxtPtr ctxt) {
++    if (ctxt == NULL) {
++        return(NULL);
++    }
++    if (ctxt->input_id == 1) {
++        return xmlDefaultExternalEntityLoader((const char *) URL, ID, ctxt);
++    }
++    xmlIOErr(XML_IO_ILLEGAL_XXE, (const char *) URL);
++    return(NULL);
++}
++
+ #define bottom_xmlIO
+ #include "elfgcchack.h"
+diff --git a/xmllint.c b/xmllint.c
+index 67f7adb..d9368c1 100644
+--- a/xmllint.c
++++ b/xmllint.c
+@@ -3019,6 +3019,7 @@ static void usage(const char *name) {
+     printf("\t--path 'paths': provide a set of paths for resources\n");
+     printf("\t--load-trace : print trace of all external entities loaded\n");
+     printf("\t--nonet : refuse to fetch DTDs or entities over network\n");
++    printf("\t--noxxe : forbid any external entity loading\n");
+     printf("\t--nocompact : do not generate compact text nodes\n");
+     printf("\t--htmlout : output results as HTML\n");
+     printf("\t--nowrap : do not put HTML doc wrapper\n");
+@@ -3461,6 +3462,10 @@ main(int argc, char **argv) {
+                    (!strcmp(argv[i], "--nonet"))) {
+ 	    options |= XML_PARSE_NONET;
+ 	    xmlSetExternalEntityLoader(xmlNoNetExternalEntityLoader);
++        } else if ((!strcmp(argv[i], "-noxxe")) ||
++                   (!strcmp(argv[i], "--noxxe"))) {
++	    options |= XML_PARSE_NOXXE;
++	    xmlSetExternalEntityLoader(xmlNoXxeExternalEntityLoader);
+         } else if ((!strcmp(argv[i], "-nocompact")) ||
+                    (!strcmp(argv[i], "--nocompact"))) {
+ 	    options &= ~XML_PARSE_COMPACT;
+-- 
+2.10.2
+
diff --git a/meta/recipes-core/libxml/libxml2_2.9.4.bb b/meta/recipes-core/libxml/libxml2_2.9.4.bb
index 0c3d683623..7d0e121be1 100644
--- a/meta/recipes-core/libxml/libxml2_2.9.4.bb
+++ b/meta/recipes-core/libxml/libxml2_2.9.4.bb
@@ -23,6 +23,7 @@ SRC_URI = "ftp://xmlsoft.org/libxml2/libxml2-${PV}.tar.gz;name=libtar \
            file://libxml2-CVE-2016-5131.patch \
            file://libxml2-CVE-2016-4658.patch \
            file://libxml2-fix_NULL_pointer_derefs.patch \
+           file://CVE-2016-9318.patch \
           "
 
 SRC_URI[libtar.md5sum] = "ae249165c173b1ff386ee8ad676815f5"