You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

140 lines
4.6 KiB

commit 8ed73eb939d6c9b79f3fa41b76916cc443196bbc
Author: Daniel Veillard <veillard@redhat.com>
Date: Thu Oct 2 16:17:09 2014 +0800
Fix for CVE-2014-3660
Issues related to the billion laugh entity expansion which happened to
escape the initial set of fixes
diff --git a/parser.c b/parser.c
index f30588c..3c72cbb 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);
@@ -2584,6 +2610,7 @@ 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)
@@ -2737,6 +2764,7 @@ 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) &&
@@ -2788,6 +2816,7 @@ 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) {
@@ -7286,6 +7315,7 @@ 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;
@@ -7392,7 +7422,7 @@ 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;
@@ -7440,7 +7470,7 @@ 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;
@@ -7626,6 +7656,7 @@ xmlParseEntityRef(xmlParserCtxtPtr ctxt) {
ctxt->sax->reference(ctxt->userData, name);
}
}
+ xmlParserEntityCheck(ctxt, 0, ent, 0);
ctxt->valid = 0;
}
@@ -7819,6 +7850,7 @@ xmlParseStringEntityRef(xmlParserCtxtPtr ctxt, const xmlChar ** str) {
"Entity '%s' not defined\n",
name);
}
+ xmlParserEntityCheck(ctxt, 0, ent, 0);
/* TODO ? check regressions ctxt->valid = 0; */
}
@@ -7978,6 +8010,7 @@ xmlParsePEReference(xmlParserCtxtPtr ctxt)
name, NULL);
ctxt->valid = 0;
}
+ xmlParserEntityCheck(ctxt, 0, NULL, 0);
} else {
/*
* Internal checking in case the entity quest barfed
@@ -8217,6 +8250,7 @@ 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