$NetBSD: patch-CVE-2023-38469,v 1.1 2025/02/26 11:43:05 nia Exp $

[PATCH] core: reject overly long TXT resource records

Closes https://github.com/lathiat/avahi/issues/455

CVE-2023-38469

https://github.com/evverx/avahi/commit/a337a1ba7d15853fb56deef1f464529af6e3a1cf.patch

--- avahi-core/rr.c.orig	2015-04-01 04:58:14.149727123 +0000
+++ avahi-core/rr.c
@@ -32,6 +32,7 @@
 #include <avahi-common/malloc.h>
 #include <avahi-common/defs.h>
 
+#include "dns.h"
 #include "rr.h"
 #include "log.h"
 #include "util.h"
@@ -688,11 +689,17 @@ int avahi_record_is_valid(AvahiRecord *r
         case AVAHI_DNS_TYPE_TXT: {
 
             AvahiStringList *strlst;
+            size_t used = 0;
 
-            for (strlst = r->data.txt.string_list; strlst; strlst = strlst->next)
+            for (strlst = r->data.txt.string_list; strlst; strlst = strlst->next) {
                 if (strlst->size > 255 || strlst->size <= 0)
                     return 0;
 
+                used += 1+strlst->size;
+                if (used > AVAHI_DNS_RDATA_MAX)
+                    return 0;
+            }
+
             return 1;
         }
     }