72 lines
2.8 KiB
Diff
72 lines
2.8 KiB
Diff
From 4c6922f763ad958c48ff66f82823ae21f2e92ee6 Mon Sep 17 00:00:00 2001
|
|
From: Nick Wellnhofer <wellnhofer@aevum.de>
|
|
Date: Tue, 13 Sep 2022 16:40:31 +0200
|
|
Subject: [PATCH] schemas: Fix null-pointer-deref in
|
|
xmlSchemaCheckCOSSTDerivedOK
|
|
|
|
Found by OSS-Fuzz.
|
|
---
|
|
result/schemas/oss-fuzz-51295_0_0.err | 2 ++
|
|
test/schemas/oss-fuzz-51295_0.xml | 1 +
|
|
test/schemas/oss-fuzz-51295_0.xsd | 4 ++++
|
|
xmlschemas.c | 15 +++++++++++++--
|
|
4 files changed, 20 insertions(+), 2 deletions(-)
|
|
create mode 100644 result/schemas/oss-fuzz-51295_0_0.err
|
|
create mode 100644 test/schemas/oss-fuzz-51295_0.xml
|
|
create mode 100644 test/schemas/oss-fuzz-51295_0.xsd
|
|
|
|
diff --git a/result/schemas/oss-fuzz-51295_0_0.err b/result/schemas/oss-fuzz-51295_0_0.err
|
|
new file mode 100644
|
|
index 00000000..1e89524f
|
|
--- /dev/null
|
|
+++ b/result/schemas/oss-fuzz-51295_0_0.err
|
|
@@ -0,0 +1,2 @@
|
|
+./test/schemas/oss-fuzz-51295_0.xsd:2: element element: Schemas parser error : element decl. 'e': The element declaration 'e' defines a circular substitution group to element declaration 'e'.
|
|
+./test/schemas/oss-fuzz-51295_0.xsd:2: element element: Schemas parser error : element decl. 'e': The element declaration 'e' defines a circular substitution group to element declaration 'e'.
|
|
diff --git a/test/schemas/oss-fuzz-51295_0.xml b/test/schemas/oss-fuzz-51295_0.xml
|
|
new file mode 100644
|
|
index 00000000..10a7e703
|
|
--- /dev/null
|
|
+++ b/test/schemas/oss-fuzz-51295_0.xml
|
|
@@ -0,0 +1 @@
|
|
+<e/>
|
|
diff --git a/test/schemas/oss-fuzz-51295_0.xsd b/test/schemas/oss-fuzz-51295_0.xsd
|
|
new file mode 100644
|
|
index 00000000..fde96af5
|
|
--- /dev/null
|
|
+++ b/test/schemas/oss-fuzz-51295_0.xsd
|
|
@@ -0,0 +1,4 @@
|
|
+<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
|
|
+ <xs:element name="e" substitutionGroup="e"/>
|
|
+ <xs:element name="t" substitutionGroup="e" type='xs:decimal'/>
|
|
+</xs:schema>
|
|
diff --git a/xmlschemas.c b/xmlschemas.c
|
|
index f31d3d1f..152b7c3f 100644
|
|
--- a/xmlschemas.c
|
|
+++ b/xmlschemas.c
|
|
@@ -13345,8 +13345,19 @@ xmlSchemaResolveElementReferences(xmlSchemaElementPtr elemDecl,
|
|
* declaration `resolved` to by the `actual value`
|
|
* of the substitutionGroup [attribute], if present"
|
|
*/
|
|
- if (elemDecl->subtypes == NULL)
|
|
- elemDecl->subtypes = substHead->subtypes;
|
|
+ if (elemDecl->subtypes == NULL) {
|
|
+ if (substHead->subtypes == NULL) {
|
|
+ /*
|
|
+ * This can happen with self-referencing substitution
|
|
+ * groups. The cycle will be detected later, but we have
|
|
+ * to set subtypes to avoid null-pointer dereferences.
|
|
+ */
|
|
+ elemDecl->subtypes = xmlSchemaGetBuiltInType(
|
|
+ XML_SCHEMAS_ANYTYPE);
|
|
+ } else {
|
|
+ elemDecl->subtypes = substHead->subtypes;
|
|
+ }
|
|
+ }
|
|
}
|
|
}
|
|
/*
|
|
--
|
|
GitLab
|
|
|