[OE-core] [PATCH 03/61] libxml2: fix CVE-2014-3660
Armin Kuster
akuster808 at gmail.com
Thu Feb 5 16:03:11 UTC 2015
From: Joe MacDonald <joe_macdonald at mentor.com>
It was discovered that the patch for CVE-2014-0191 for libxml2 is
incomplete. It is still possible to have libxml2 incorrectly perform
entity substituton even when the application using libxml2 explicitly
disables the feature. This can allow a remote denial-of-service attack on
systems with libxml2 prior to 2.9.2.
References:
http://www.openwall.com/lists/oss-security/2014/10/17/7
https://www.ncsc.nl/actueel/nieuwsberichten/kwetsbaarheid-ontdekt-in-libxml2.html
(From OE-Core rev: 643597a5c432b2e02033d0cefa3ba4da980d078f)
Signed-off-by: Joe MacDonald <joe_macdonald at mentor.com>
Signed-off-by: Ross Burton <ross.burton at intel.com>
Signed-off-by: Richard Purdie <richard.purdie at linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808 at gmail.com>
---
meta/recipes-core/libxml/libxml2.inc | 1 +
.../libxml/libxml2/libxml2-CVE-2014-3660.patch | 147 +++++++++++++++++++++
2 files changed, 148 insertions(+)
create mode 100644 meta/recipes-core/libxml/libxml2/libxml2-CVE-2014-3660.patch
diff --git a/meta/recipes-core/libxml/libxml2.inc b/meta/recipes-core/libxml/libxml2.inc
index bcf9a62..c729c19 100644
--- a/meta/recipes-core/libxml/libxml2.inc
+++ b/meta/recipes-core/libxml/libxml2.inc
@@ -21,6 +21,7 @@ SRC_URI = "ftp://xmlsoft.org/libxml2/libxml2-${PV}.tar.gz;name=libtar \
file://libxml2-CVE-2014-0191-fix.patch \
file://python-sitepackages-dir.patch \
file://libxml-m4-use-pkgconfig.patch \
+ file://libxml2-CVE-2014-3660.patch \
"
BINCONFIG = "${bindir}/xml2-config"
diff --git a/meta/recipes-core/libxml/libxml2/libxml2-CVE-2014-3660.patch b/meta/recipes-core/libxml/libxml2/libxml2-CVE-2014-3660.patch
new file mode 100644
index 0000000..b9621c9
--- /dev/null
+++ b/meta/recipes-core/libxml/libxml2/libxml2-CVE-2014-3660.patch
@@ -0,0 +1,147 @@
+From be2a7edaf289c5da74a4f9ed3a0b6c733e775230 Mon Sep 17 00:00:00 2001
+From: Daniel Veillard <veillard at redhat.com>
+Date: Thu, 16 Oct 2014 13:59:47 +0800
+Subject: Fix for CVE-2014-3660
+
+Issues related to the billion laugh entity expansion which happened to
+escape the initial set of fixes
+
+Upstream-status: Backport
+Reference: https://git.gnome.org/browse/libxml2/commit/?id=be2a7edaf289c5da74a4f9ed3a0b6c733e775230&context=3&ignorews=0&ss=0
+
+Signed-off-by: Joe MacDonald <joe_macdonald at mentor.com>
+
+diff --git a/parser.c b/parser.c
+index f51e8d2..1d93967 100644
+--- a/parser.c
++++ b/parser.c
+@@ -130,6 +130,29 @@ xmlParserEntityCheck(xmlParserCtxtPtr ctxt, size_t size,
+ return (0);
+ if (ctxt->lastError.code == XML_ERR_ENTITY_LOOP)
+ return (1);
++
++ /*
++ * This may look absurd but is needed to detect
++ * entities problems
++ */
++ if ((ent != NULL) && (ent->etype != XML_INTERNAL_PREDEFINED_ENTITY) &&
++ (ent->content != NULL) && (ent->checked == 0)) {
++ unsigned long oldnbent = ctxt->nbentities;
++ xmlChar *rep;
++
++ ent->checked = 1;
++
++ rep = xmlStringDecodeEntities(ctxt, ent->content,
++ XML_SUBSTITUTE_REF, 0, 0, 0);
++
++ ent->checked = (ctxt->nbentities - oldnbent + 1) * 2;
++ if (rep != NULL) {
++ if (xmlStrchr(rep, '<'))
++ ent->checked |= 1;
++ xmlFree(rep);
++ rep = NULL;
++ }
++ }
+ if (replacement != 0) {
+ if (replacement < XML_MAX_TEXT_LENGTH)
+ return(0);
+@@ -189,9 +212,12 @@ xmlParserEntityCheck(xmlParserCtxtPtr ctxt, size_t size,
+ return (0);
+ } else {
+ /*
+- * strange we got no data for checking just return
++ * strange we got no data for checking
+ */
+- return (0);
++ if (((ctxt->lastError.code != XML_ERR_UNDECLARED_ENTITY) &&
++ (ctxt->lastError.code != XML_WAR_UNDECLARED_ENTITY)) ||
++ (ctxt->nbentities <= 10000))
++ return (0);
+ }
+ xmlFatalErr(ctxt, XML_ERR_ENTITY_LOOP, NULL);
+ return (1);
+@@ -2589,6 +2615,7 @@ xmlParserHandlePEReference(xmlParserCtxtPtr ctxt) {
+ name, NULL);
+ ctxt->valid = 0;
+ }
++ xmlParserEntityCheck(ctxt, 0, NULL, 0);
+ } else if (ctxt->input->free != deallocblankswrapper) {
+ input = xmlNewBlanksWrapperInputStream(ctxt, entity);
+ if (xmlPushInput(ctxt, input) < 0)
+@@ -2759,6 +2786,7 @@ xmlStringLenDecodeEntities(xmlParserCtxtPtr ctxt, const xmlChar *str, int len,
+ if ((ctxt->lastError.code == XML_ERR_ENTITY_LOOP) ||
+ (ctxt->lastError.code == XML_ERR_INTERNAL_ERROR))
+ goto int_error;
++ xmlParserEntityCheck(ctxt, 0, ent, 0);
+ if (ent != NULL)
+ ctxt->nbentities += ent->checked / 2;
+ if ((ent != NULL) &&
+@@ -2810,6 +2838,7 @@ xmlStringLenDecodeEntities(xmlParserCtxtPtr ctxt, const xmlChar *str, int len,
+ ent = xmlParseStringPEReference(ctxt, &str);
+ if (ctxt->lastError.code == XML_ERR_ENTITY_LOOP)
+ goto int_error;
++ xmlParserEntityCheck(ctxt, 0, ent, 0);
+ if (ent != NULL)
+ ctxt->nbentities += ent->checked / 2;
+ if (ent != NULL) {
+@@ -7312,6 +7341,7 @@ xmlParseReference(xmlParserCtxtPtr ctxt) {
+ (ret != XML_WAR_UNDECLARED_ENTITY)) {
+ xmlFatalErrMsgStr(ctxt, XML_ERR_UNDECLARED_ENTITY,
+ "Entity '%s' failed to parse\n", ent->name);
++ xmlParserEntityCheck(ctxt, 0, ent, 0);
+ } else if (list != NULL) {
+ xmlFreeNodeList(list);
+ list = NULL;
+@@ -7418,7 +7448,7 @@ xmlParseReference(xmlParserCtxtPtr ctxt) {
+ /*
+ * We are copying here, make sure there is no abuse
+ */
+- ctxt->sizeentcopy += ent->length;
++ ctxt->sizeentcopy += ent->length + 5;
+ if (xmlParserEntityCheck(ctxt, 0, ent, ctxt->sizeentcopy))
+ return;
+
+@@ -7466,7 +7496,7 @@ xmlParseReference(xmlParserCtxtPtr ctxt) {
+ /*
+ * We are copying here, make sure there is no abuse
+ */
+- ctxt->sizeentcopy += ent->length;
++ ctxt->sizeentcopy += ent->length + 5;
+ if (xmlParserEntityCheck(ctxt, 0, ent, ctxt->sizeentcopy))
+ return;
+
+@@ -7652,6 +7682,7 @@ xmlParseEntityRef(xmlParserCtxtPtr ctxt) {
+ ctxt->sax->reference(ctxt->userData, name);
+ }
+ }
++ xmlParserEntityCheck(ctxt, 0, ent, 0);
+ ctxt->valid = 0;
+ }
+
+@@ -7845,6 +7876,7 @@ xmlParseStringEntityRef(xmlParserCtxtPtr ctxt, const xmlChar ** str) {
+ "Entity '%s' not defined\n",
+ name);
+ }
++ xmlParserEntityCheck(ctxt, 0, ent, 0);
+ /* TODO ? check regressions ctxt->valid = 0; */
+ }
+
+@@ -8004,6 +8036,7 @@ xmlParsePEReference(xmlParserCtxtPtr ctxt)
+ name, NULL);
+ ctxt->valid = 0;
+ }
++ xmlParserEntityCheck(ctxt, 0, NULL, 0);
+ } else {
+ /*
+ * Internal checking in case the entity quest barfed
+@@ -8243,6 +8276,7 @@ xmlParseStringPEReference(xmlParserCtxtPtr ctxt, const xmlChar **str) {
+ name, NULL);
+ ctxt->valid = 0;
+ }
++ xmlParserEntityCheck(ctxt, 0, NULL, 0);
+ } else {
+ /*
+ * Internal checking in case the entity quest barfed
+--
+cgit v0.10.1
+
--
1.9.1
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