xref: /third_party/libxml2/backport-malloc-fail-Fix-memory-leak-in-WXS_ADD_-LOCAL-GLOBAL.patch

From 9afb6c5fb86a0dca167b6ae60aa05211a25e435f Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Sun, 5 Mar 2023 14:09:49 +0100
Subject: [PATCH] malloc-fail: Fix memory leak in WXS_ADD_{LOCAL,GLOBAL}

It's somewhat dangerous to add the cleanup code to a macro, but
otherwise we'd have to fix all the call sites.

Found with libFuzzer, see #344.

Reference:https://github.com/GNOME/libxml2/commit/9afb6c5fb86a0dca167b6ae60aa05211a25e435f
Conflict:NA
---
 xmlschemas.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/xmlschemas.c b/xmlschemas.c
index 5b93937..724920b 100644
--- a/xmlschemas.c
+++ b/xmlschemas.c
@@ -305,10 +305,20 @@ static const xmlChar *xmlNamespaceNs = (const xmlChar *)
 #define WXS_SCHEMA(ctx) (ctx)->schema
 
 #define WXS_ADD_LOCAL(ctx, item) \
-    xmlSchemaAddItemSize(&(WXS_BUCKET(ctx)->locals), 10, item)
+    do { \
+        if (xmlSchemaAddItemSize(&(WXS_BUCKET(ctx)->locals), 10, item) < 0) { \
+            xmlFree(item); \
+            item = NULL; \
+        } \
+    } while (0)
 
 #define WXS_ADD_GLOBAL(ctx, item) \
-    xmlSchemaAddItemSize(&(WXS_BUCKET(ctx)->globals), 5, item)
+    do { \
+        if (xmlSchemaAddItemSize(&(WXS_BUCKET(ctx)->globals), 5, item) < 0) { \
+            xmlFree(item); \
+            item = NULL; \
+        } \
+    } while (0)
 
 #define WXS_ADD_PENDING(ctx, item) \
     xmlSchemaAddItemSize(&((ctx)->constructor->pending), 10, item)
@@ -3764,8 +3774,7 @@ xmlSchemaAddItemSize(xmlSchemaItemListPtr *list, int initialSize, void *item)
 	if (*list == NULL)
 	    return(-1);
     }
-    xmlSchemaItemListAddSize(*list, initialSize, item);
-    return(0);
+    return(xmlSchemaItemListAddSize(*list, initialSize, item));
 }
 
 /**
-- 
2.27.0