libxml2: fix CVE-2025-6021

Upstream-Status: Backport from https://gitlab.gnome.org/GNOME/libxml2/-/commit/acbbeef9f5dcdcc901c5f3fa14d583ef8cfd22f0

(From OE-Core rev: 8777f1b344c7f66a7ef4291bb59af2a5fb466b6a)

Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

meta/recipes-core/libxml/libxml2/CVE-2025-6021.patch

@@ -0,0 +1,56 @@
+From acbbeef9f5dcdcc901c5f3fa14d583ef8cfd22f0 Mon Sep 17 00:00:00 2001
+From: Nick Wellnhofer <wellnhofer@aevum.de>
+Date: Tue, 27 May 2025 12:53:17 +0200
+Subject: [PATCH] tree: Fix integer overflow in xmlBuildQName
+
+This issue affects memory safety.
+
+Fixes #926. 
+
+Upstream-Status: Backport [https://gitlab.gnome.org/GNOME/libxml2/-/commit/acbbeef9f5dcdcc901c5f3fa14d583ef8cfd22f0]
+CVE: CVE-2025-6021
+Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
+---
+ tree.c | 12 +++++++++---
+ 1 file changed, 9 insertions(+), 3 deletions(-)
+
+diff --git a/tree.c b/tree.c
+index dc3ac4f..f89e3cd 100644
+--- a/tree.c
++++ b/tree.c
+@@ -47,6 +47,10 @@
+ #include "private/error.h"
+ #include "private/tree.h"
+ 
++#ifndef SIZE_MAX
++#define SIZE_MAX ((size_t) -1)
++#endif
++
+ int __xmlRegisterCallbacks = 0;
+ 
+ /************************************************************************
+@@ -216,16 +220,18 @@ xmlGetParameterEntityFromDtd(const xmlDtd *dtd, const xmlChar *name) {
+ xmlChar *
+ xmlBuildQName(const xmlChar *ncname, const xmlChar *prefix,
+ 	      xmlChar *memory, int len) {
+-    int lenn, lenp;
++    size_t lenn, lenp;
+     xmlChar *ret;
+ 
+-    if (ncname == NULL) return(NULL);
++    if ((ncname == NULL) || (len < 0)) return(NULL);
+     if (prefix == NULL) return((xmlChar *) ncname);
+ 
+     lenn = strlen((char *) ncname);
+     lenp = strlen((char *) prefix);
++    if (lenn >= SIZE_MAX - lenp - 1)
++        return(NULL);
+ 
+-    if ((memory == NULL) || (len < lenn + lenp + 2)) {
++    if ((memory == NULL) || ((size_t) len < lenn + lenp + 2)) {
+ 	ret = (xmlChar *) xmlMallocAtomic(lenn + lenp + 2);
+ 	if (ret == NULL) {
+ 	    xmlTreeErrMemory("building QName");
+-- 
+2.49.0
+

meta/recipes-core/libxml/libxml2_2.12.10.bb

@@ -20,6 +20,7 @@ SRC_URI += "http://www.w3.org/XML/Test/xmlts20130923.tar;subdir=${BP};name=testt
            file://install-tests.patch \
            file://CVE-2025-32414.patch \
            file://CVE-2025-32415.patch \
+           file://CVE-2025-6021.patch \
            "
 
 SRC_URI[archive.sha256sum] = "c3d8c0c34aa39098f66576fe51969db12a5100b956233dc56506f7a8679be995"