From 513f25ce12357f963d8917cb2f49b2c2020f4165 Mon Sep 17 00:00:00 2001
From: Tobias Brunner <tobias@strongswan.org>
Date: Wed, 25 Mar 2026 09:51:31 +0100
Subject: [PATCH] tnccs_11: Avoid crash if TNCCS-ReasonStrings is empty or only
 contains empty nodes

`xmlNodeGetContent()` returns `NULL` if `child` is `NULL`, which causes
a segmentation fault in `chunk_from_str()`.

Fixes: ec1eab03195b ("fixed XML parsing of TNCCS 1.1 ReasonString message")
---
 .../plugins/tnccs_11/messages/tnccs_reason_strings_msg.c     | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/libtnccs/plugins/tnccs_11/messages/tnccs_reason_strings_msg.c b/src/libtnccs/plugins/tnccs_11/messages/tnccs_reason_strings_msg.c
index 859f957dc..9cba2dc06 100644
--- a/src/libtnccs/plugins/tnccs_11/messages/tnccs_reason_strings_msg.c
+++ b/src/libtnccs/plugins/tnccs_11/messages/tnccs_reason_strings_msg.c
@@ -126,6 +126,11 @@ tnccs_msg_t *tnccs_reason_strings_msg_create_from_node(xmlNodePtr node,
 		}
 		break;
 	}
+	if (!child)
+	{
+		error_msg = "ReasonString tag not found";
+		goto fatal;
+	}
 
 	lang_string = xmlGetProp(child, "lang");
 	if (!lang_string)