libxml2: Fix CVE-2026-86141

This patch applies the upstream fix as referenced in [2],
using the commit shown in [1].

[1] https://github.com/GNOME/libxml2/commit/e89a8aae4c9b40cdafcf66b3f9e57c62db37bb55
[2] https://nvd.nist.gov/vuln/detail/CVE-2026-86141

(From OE-Core rev: ab19dd964fc00af7868fb1e144f3c3266cd50a99)

Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
Signed-off-by: Yoann Congal <yoann.congal@smile.fr>
Signed-off-by: Paul Barker <paul@pbarker.dev>

meta/recipes-core/libxml/libxml2/CVE-2026-86141.patch

@@ -0,0 +1,35 @@
+From adb9287ae35770d9b281ed8f2160774198fbaf25 Mon Sep 17 00:00:00 2001
+From: Daniel Garcia Moreno <daniel.garcia@suse.com>
+Date: Mon, 4 May 2026 07:56:18 +0200
+Subject: [PATCH] xmlregexp: Calc string length after null checking
+
+Fix https://gitlab.gnome.org/GNOME/libxml2/-/work_items/1107
+
+CVE: CVE-2026-86141
+Upstream-Status: Backport [https://github.com/GNOME/libxml2/commit/e89a8aae4c9b40cdafcf66b3f9e57c62db37bb55]
+
+(cherry picked from commit e89a8aae4c9b40cdafcf66b3f9e57c62db37bb55)
+Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
+---
+ xmlregexp.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/xmlregexp.c b/xmlregexp.c
+index 320a35ce..72e8e459 100644
+--- a/xmlregexp.c
++++ b/xmlregexp.c
+@@ -702,12 +702,12 @@ xmlRegNewParserCtxt(const xmlChar *string) {
+ 	return(NULL);
+     memset(ret, 0, sizeof(xmlRegParserCtxt));
+     if (string != NULL) {
+-	ret->string = xmlStrdup(string);
+-	ret->len = strlen((const char *) ret->string);
++        ret->string = xmlStrdup(string);
+         if (ret->string == NULL) {
+             xmlFree(ret);
+             return(NULL);
+         }
++        ret->len = strlen((const char *) ret->string);
+     }
+     ret->cur = ret->string;
+     ret->neg = 0;

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

@@ -35,6 +35,7 @@ SRC_URI += "http://www.w3.org/XML/Test/xmlts20130923.tar;subdir=${BP};name=testt
            file://CVE-2026-86137.patch \
            file://CVE-2026-86138.patch \
            file://CVE-2026-86140.patch \
+           file://CVE-2026-86141.patch \
            "
 
 SRC_URI[archive.sha256sum] = "c3d8c0c34aa39098f66576fe51969db12a5100b956233dc56506f7a8679be995"