blob: 907f2c4d47da86fdfdb31fca4b2340c527231dcf [file] [log] [blame]
From e4f85f1bd2eb34d9b49da9154a4cc3a1bc284f68 Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Fri, 7 Apr 2023 11:46:35 +0200
Subject: [PATCH] [CVE-2023-28484] Fix null deref in xmlSchemaFixupComplexType
Fix a null pointer dereference when parsing (invalid) XML schemas.
Thanks to Robby Simpson for the report!
Fixes #491.
CVE: CVE-2023-28484
Upstream-Status: Backport [https://gitlab.gnome.org/GNOME/libxml2/-/commit/e4f85f1bd2eb34d9b49da9154a4cc3a1bc284f68]
Signed-off-by: Peter Marko <peter.marko@siemens.com>
---
result/schemas/issue491_0_0.err | 1 +
test/schemas/issue491_0.xml | 1 +
test/schemas/issue491_0.xsd | 18 ++++++++++++++++++
xmlschemas.c | 2 +-
4 files changed, 21 insertions(+), 1 deletion(-)
create mode 100644 result/schemas/issue491_0_0.err
create mode 100644 test/schemas/issue491_0.xml
create mode 100644 test/schemas/issue491_0.xsd
diff --git a/result/schemas/issue491_0_0.err b/result/schemas/issue491_0_0.err
new file mode 100644
index 00000000..9b2bb969
--- /dev/null
+++ b/result/schemas/issue491_0_0.err
@@ -0,0 +1 @@
+./test/schemas/issue491_0.xsd:8: element complexType: Schemas parser error : complex type 'ChildType': The content type of both, the type and its base type, must either 'mixed' or 'element-only'.
diff --git a/test/schemas/issue491_0.xml b/test/schemas/issue491_0.xml
new file mode 100644
index 00000000..e2b2fc2e
--- /dev/null
+++ b/test/schemas/issue491_0.xml
@@ -0,0 +1 @@
+<Child xmlns="http://www.test.com">5</Child>
diff --git a/test/schemas/issue491_0.xsd b/test/schemas/issue491_0.xsd
new file mode 100644
index 00000000..81702649
--- /dev/null
+++ b/test/schemas/issue491_0.xsd
@@ -0,0 +1,18 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns="http://www.test.com" targetNamespace="http://www.test.com" elementFormDefault="qualified" attributeFormDefault="unqualified">
+ <xs:complexType name="BaseType">
+ <xs:simpleContent>
+ <xs:extension base="xs:int" />
+ </xs:simpleContent>
+ </xs:complexType>
+ <xs:complexType name="ChildType">
+ <xs:complexContent>
+ <xs:extension base="BaseType">
+ <xs:sequence>
+ <xs:element name="bad" type="xs:int" minOccurs="0" maxOccurs="1"/>
+ </xs:sequence>
+ </xs:extension>
+ </xs:complexContent>
+ </xs:complexType>
+ <xs:element name="Child" type="ChildType" />
+</xs:schema>
diff --git a/xmlschemas.c b/xmlschemas.c
index 6a353858..a4eaf591 100644
--- a/xmlschemas.c
+++ b/xmlschemas.c
@@ -18632,7 +18632,7 @@ xmlSchemaFixupComplexType(xmlSchemaParserCtxtPtr pctxt,
"allowed to appear inside other model groups",
NULL, NULL);
- } else if (! dummySequence) {
+ } else if ((!dummySequence) && (baseType->subtypes != NULL)) {
xmlSchemaTreeItemPtr effectiveContent =
(xmlSchemaTreeItemPtr) type->subtypes;
/*
--
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