xref: /third_party/libxml2/backport-malloc-fail-Fix-null-deref-in-xmlGet-Min-Max-Occurs.patch

From 0263b357567870c20de26c90dbc962aec81c5a19 Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Sun, 5 Mar 2023 14:08:35 +0100
Subject: [PATCH] malloc-fail: Fix null deref in xmlGet{Min,Max}Occurs

Also report memory error in xmlSchemaGetNodeContent.

Found with libFuzzer, see #344.

Reference:https://github.com/GNOME/libxml2/commit/0263b357567870c20de26c90dbc962aec81c5a19
Conflict:NA
---
 xmlschemas.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/xmlschemas.c b/xmlschemas.c
index 9be7999..c68103c 100644
--- a/xmlschemas.c
+++ b/xmlschemas.c
@@ -4760,6 +4760,8 @@ xmlSchemaGetNodeContent(xmlSchemaParserCtxtPtr ctxt, xmlNodePtr node)
 	val = xmlStrdup((xmlChar *)"");
     ret = xmlDictLookup(ctxt->dict, val, -1);
     xmlFree(val);
+    if (ret == NULL)
+        xmlSchemaPErrMemory(ctxt, "getting node content", node);
     return(ret);
 }
 
@@ -6103,6 +6105,8 @@ xmlGetMaxOccurs(xmlSchemaParserCtxtPtr ctxt, xmlNodePtr node,
     if (attr == NULL)
 	return (def);
     val = xmlSchemaGetNodeContent(ctxt, (xmlNodePtr) attr);
+    if (val == NULL)
+        return (def);
 
     if (xmlStrEqual(val, (const xmlChar *) "unbounded")) {
 	if (max != UNBOUNDED) {
@@ -6177,6 +6181,8 @@ xmlGetMinOccurs(xmlSchemaParserCtxtPtr ctxt, xmlNodePtr node,
     if (attr == NULL)
 	return (def);
     val = xmlSchemaGetNodeContent(ctxt, (xmlNodePtr) attr);
+    if (val == NULL)
+	return (def);
     cur = val;
     while (IS_BLANK_CH(*cur))
         cur++;
-- 
2.27.0