From 36e9222c42ff74a71ea4e52150285e2264ad4dd0 Mon Sep 17 00:00:00 2001
From: z2_ <88509734+z2-2z@users.noreply.github.com>
Date: Thu, 20 Jun 2024 21:57:07 +0200
Subject: [PATCH] x509asn1: prevent NULL dereference

Closes #13978
---
 lib/vtls/x509asn1.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/vtls/x509asn1.c b/lib/vtls/x509asn1.c
index c896838de7..f71ab0b90a 100644
--- a/lib/vtls/x509asn1.c
+++ b/lib/vtls/x509asn1.c
@@ -695,6 +695,11 @@ static CURLcode encodeDN(struct dynbuf *store, struct Curl_asn1Element *dn)
 
       str = Curl_dyn_ptr(&temp);
 
+      if(!str) {
+        result = CURLE_BAD_FUNCTION_ARGUMENT;
+        goto error;
+      }
+
       /* Encode delimiter.
          If attribute has a short uppercase name, delimiter is ", ". */
       for(p3 = str; ISUPPER(*p3); p3++)
-- 
2.47.3