[OE-core] [PATCH] libxml2: Security fix CVE-2016-5131
Yi Zhao
yi.zhao at windriver.com
Fri Dec 16 00:42:24 UTC 2016
在 2016年12月16日 03:01, Ahsan, Noor 写道:
> Can we have this patch merged on morty branch?
Yes
//Yi
>
> Noor
>
> -----Original Message-----
> From: openembedded-core-bounces at lists.openembedded.org [mailto:openembedded-core-bounces at lists.openembedded.org] On Behalf Of Yi Zhao
> Sent: Monday, November 28, 2016 2:56 PM
> To: openembedded-core at lists.openembedded.org
> Subject: [OE-core] [PATCH] libxml2: Security fix CVE-2016-5131
>
> CVE-2016-5131 libxml2: Use-after-free vulnerability in libxml2 through 2.9.4, as used in Google Chrome before 52.0.2743.82, allows remote attackers to cause a denial of service or possibly have unspecified other impact via vectors related to the XPointer range-to function.
>
> External References:
> https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-5131
>
> Patch from:
> https://git.gnome.org/browse/libxml2/commit/?id=9ab01a277d71f54d3143c2cf333c5c2e9aaedd9e
>
> Signed-off-by: Yi Zhao <yi.zhao at windriver.com>
> ---
> .../libxml/libxml2/libxml2-CVE-2016-5131.patch | 180 +++++++++++++++++++++
> meta/recipes-core/libxml/libxml2_2.9.4.bb | 1 +
> 2 files changed, 181 insertions(+)
> create mode 100644 meta/recipes-core/libxml/libxml2/libxml2-CVE-2016-5131.patch
>
> diff --git a/meta/recipes-core/libxml/libxml2/libxml2-CVE-2016-5131.patch b/meta/recipes-core/libxml/libxml2/libxml2-CVE-2016-5131.patch
> new file mode 100644
> index 0000000..9d47d02
> --- /dev/null
> +++ b/meta/recipes-core/libxml/libxml2/libxml2-CVE-2016-5131.patch
> @@ -0,0 +1,180 @@
> +From 9ab01a277d71f54d3143c2cf333c5c2e9aaedd9e Mon Sep 17 00:00:00 2001
> +From: Nick Wellnhofer <wellnhofer at aevum.de>
> +Date: Tue, 28 Jun 2016 14:22:23 +0200
> +Subject: [PATCH] Fix XPointer paths beginning with range-to
> +
> +The old code would invoke the broken xmlXPtrRangeToFunction. range-to
> +isn't really a function but a special kind of location step. Remove
> +this function and always handle range-to in the XPath code.
> +
> +The old xmlXPtrRangeToFunction could also be abused to trigger a
> +use-after-free error with the potential for remote code execution.
> +
> +Found with afl-fuzz.
> +
> +Fixes CVE-2016-5131.
> +
> +CVE: CVE-2016-5131
> +Upstream-Status: Backport
> +https://git.gnome.org/browse/libxml2/commit/?id=9ab01a277d71f54d3143c2c
> +f333c5c2e9aaedd9e
> +
> +Signed-off-by: Yi Zhao <yi.zhao at windirver.com>
> +---
> + result/XPath/xptr/vidbase | 13 ++++++++
> + test/XPath/xptr/vidbase | 1 +
> + xpath.c | 7 ++++-
> + xpointer.c | 76 ++++-------------------------------------------
> + 4 files changed, 26 insertions(+), 71 deletions(-)
> +
> +diff --git a/result/XPath/xptr/vidbase b/result/XPath/xptr/vidbase
> +index 8b9e92d..f19193e 100644
> +--- a/result/XPath/xptr/vidbase
> ++++ b/result/XPath/xptr/vidbase
> +@@ -17,3 +17,16 @@ Object is a Location Set:
> + To node
> + ELEMENT p
> +
> ++
> ++========================
> ++Expression: xpointer(range-to(id('chapter2')))
> ++Object is a Location Set:
> ++1 : Object is a range :
> ++ From node
> ++ /
> ++ To node
> ++ ELEMENT chapter
> ++ ATTRIBUTE id
> ++ TEXT
> ++ content=chapter2
> ++
> +diff --git a/test/XPath/xptr/vidbase b/test/XPath/xptr/vidbase index
> +b146383..884b106 100644
> +--- a/test/XPath/xptr/vidbase
> ++++ b/test/XPath/xptr/vidbase
> +@@ -1,2 +1,3 @@
> + xpointer(id('chapter1')/p)
> + xpointer(id('chapter1')/p[1]/range-to(following-sibling::p[2]))
> ++xpointer(range-to(id('chapter2')))
> +diff --git a/xpath.c b/xpath.c
> +index d992841..5a01b1b 100644
> +--- a/xpath.c
> ++++ b/xpath.c
> +@@ -10691,13 +10691,18 @@ xmlXPathCompPathExpr(xmlXPathParserContextPtr ctxt) {
> + lc = 1;
> + break;
> + } else if ((NXT(len) == '(')) {
> +- /* Note Type or Function */
> ++ /* Node Type or Function */
> + if (xmlXPathIsNodeType(name)) {
> + #ifdef DEBUG_STEP
> + xmlGenericError(xmlGenericErrorContext,
> + "PathExpr: Type search\n");
> + #endif
> + lc = 1;
> ++#ifdef LIBXML_XPTR_ENABLED
> ++ } else if (ctxt->xptr &&
> ++ xmlStrEqual(name, BAD_CAST "range-to")) {
> ++ lc = 1;
> ++#endif
> + } else {
> + #ifdef DEBUG_STEP
> + xmlGenericError(xmlGenericErrorContext,
> +diff --git a/xpointer.c b/xpointer.c
> +index 676c510..d74174a 100644
> +--- a/xpointer.c
> ++++ b/xpointer.c
> +@@ -1332,8 +1332,6 @@ xmlXPtrNewContext(xmlDocPtr doc, xmlNodePtr here, xmlNodePtr origin) {
> + ret->here = here;
> + ret->origin = origin;
> +
> +- xmlXPathRegisterFunc(ret, (xmlChar *)"range-to",
> +- xmlXPtrRangeToFunction);
> + xmlXPathRegisterFunc(ret, (xmlChar *)"range",
> + xmlXPtrRangeFunction);
> + xmlXPathRegisterFunc(ret, (xmlChar *)"range-inside", @@ -2243,76
> ++2241,14 @@ xmlXPtrRangeInsideFunction(xmlXPathParserContextPtr ctxt,
> +int nargs) {
> + * @nargs: the number of args
> + *
> + * Implement the range-to() XPointer function
> ++ *
> ++ * Obsolete. range-to is not a real function but a special type of
> ++ location
> ++ * step which is handled in xpath.c.
> + */
> + void
> +-xmlXPtrRangeToFunction(xmlXPathParserContextPtr ctxt, int nargs) {
> +- xmlXPathObjectPtr range;
> +- const xmlChar *cur;
> +- xmlXPathObjectPtr res, obj;
> +- xmlXPathObjectPtr tmp;
> +- xmlLocationSetPtr newset = NULL;
> +- xmlNodeSetPtr oldset;
> +- int i;
> +-
> +- if (ctxt == NULL) return;
> +- CHECK_ARITY(1);
> +- /*
> +- * Save the expression pointer since we will have to evaluate
> +- * it multiple times. Initialize the new set.
> +- */
> +- CHECK_TYPE(XPATH_NODESET);
> +- obj = valuePop(ctxt);
> +- oldset = obj->nodesetval;
> +- ctxt->context->node = NULL;
> +-
> +- cur = ctxt->cur;
> +- newset = xmlXPtrLocationSetCreate(NULL);
> +-
> +- for (i = 0; i < oldset->nodeNr; i++) {
> +- ctxt->cur = cur;
> +-
> +- /*
> +- * Run the evaluation with a node list made of a single item
> +- * in the nodeset.
> +- */
> +- ctxt->context->node = oldset->nodeTab[i];
> +- tmp = xmlXPathNewNodeSet(ctxt->context->node);
> +- valuePush(ctxt, tmp);
> +-
> +- xmlXPathEvalExpr(ctxt);
> +- CHECK_ERROR;
> +-
> +- /*
> +- * The result of the evaluation need to be tested to
> +- * decided whether the filter succeeded or not
> +- */
> +- res = valuePop(ctxt);
> +- range = xmlXPtrNewRangeNodeObject(oldset->nodeTab[i], res);
> +- if (range != NULL) {
> +- xmlXPtrLocationSetAdd(newset, range);
> +- }
> +-
> +- /*
> +- * Cleanup
> +- */
> +- if (res != NULL)
> +- xmlXPathFreeObject(res);
> +- if (ctxt->value == tmp) {
> +- res = valuePop(ctxt);
> +- xmlXPathFreeObject(res);
> +- }
> +-
> +- ctxt->context->node = NULL;
> +- }
> +-
> +- /*
> +- * The result is used as the new evaluation set.
> +- */
> +- xmlXPathFreeObject(obj);
> +- ctxt->context->node = NULL;
> +- ctxt->context->contextSize = -1;
> +- ctxt->context->proximityPosition = -1;
> +- valuePush(ctxt, xmlXPtrWrapLocationSet(newset));
> ++xmlXPtrRangeToFunction(xmlXPathParserContextPtr ctxt,
> ++ int nargs ATTRIBUTE_UNUSED) {
> ++ XP_ERROR(XPATH_EXPR_ERROR);
> + }
> +
> + /**
> +--
> +2.7.4
> +
> diff --git a/meta/recipes-core/libxml/libxml2_2.9.4.bb b/meta/recipes-core/libxml/libxml2_2.9.4.bb
> index 59874be..1fed90b 100644
> --- a/meta/recipes-core/libxml/libxml2_2.9.4.bb
> +++ b/meta/recipes-core/libxml/libxml2_2.9.4.bb
> @@ -19,6 +19,7 @@ SRC_URI = "ftp://xmlsoft.org/libxml2/libxml2-${PV}.tar.gz;name=libtar \
> file://run-ptest \
> file://python-sitepackages-dir.patch \
> file://libxml-m4-use-pkgconfig.patch \
> + file://libxml2-CVE-2016-5131.patch \
> "
>
> SRC_URI[libtar.md5sum] = "ae249165c173b1ff386ee8ad676815f5"
> --
> 2.7.4
>
> --
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