From 640bd2b98ff33e49b42f1087650ebe20d92259a4 Mon Sep 17 00:00:00 2001 From: Yi Zhao Date: Mon, 28 Nov 2016 17:55:40 +0800 Subject: 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 Signed-off-by: Ross Burton --- .../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 (limited to 'meta') 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 0000000000..9d47d023a9 --- /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 +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=9ab01a277d71f54d3143c2cf333c5c2e9aaedd9e + +Signed-off-by: Yi Zhao +--- + 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 59874bec2c..1fed90b07e 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" -- cgit v1.2.3