libxml2/Fix-quadratic-behavior-when-looking-up-xml-attribute.patch
2021-05-29 17:30:59 +08:00

45 lines
1.2 KiB
Diff

From 688b41a0fb06cf1ab5173308f6a8db5089ba6e14 Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Mon, 1 Mar 2021 14:17:42 +0100
Subject: [PATCH] Fix quadratic behavior when looking up xml:* attributes
Add a special case for the predefined XML namespace when looking up DTD
attribute defaults in xmlGetPropNodeInternal to avoid calling
xmlGetNsList.
This fixes quadratic behavior in
- xmlNodeGetBase
- xmlNodeGetLang
- xmlNodeGetSpacePreserve
Found by OSS-Fuzz.
---
tree.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/tree.c b/tree.c
index d6ea704..617e818 100644
--- a/tree.c
+++ b/tree.c
@@ -6589,6 +6589,16 @@ xmlGetPropNodeInternal(const xmlNode *node, const xmlChar *name,
attrDecl = xmlGetDtdQAttrDesc(doc->extSubset,
elemQName, name, NULL);
}
+ } else if (xmlStrEqual(nsName, XML_XML_NAMESPACE)) {
+ /*
+ * The XML namespace must be bound to prefix 'xml'.
+ */
+ attrDecl = xmlGetDtdQAttrDesc(doc->intSubset,
+ elemQName, name, BAD_CAST "xml");
+ if ((attrDecl == NULL) && (doc->extSubset != NULL)) {
+ attrDecl = xmlGetDtdQAttrDesc(doc->extSubset,
+ elemQName, name, BAD_CAST "xml");
+ }
} else {
xmlNsPtr *nsList, *cur;
--
1.8.3.1