From 4b0a38a28e47cb58a2f3d1224fcd9790620230a4 Mon Sep 17 00:00:00 2001
From: jmestwa-coder <jmestwa@gmail.com>
Date: Tue, 24 Mar 2026 14:07:02 +0530
Subject: [PATCH] Resolver: reject PTR answers with out-of-bounds RDLENGTH

---
 src/core/ngx_resolver.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/core/ngx_resolver.c b/src/core/ngx_resolver.c
index f8f677878..98446732c 100644
--- a/src/core/ngx_resolver.c
+++ b/src/core/ngx_resolver.c
@@ -3320,6 +3320,10 @@ valid:
 
         i += sizeof(ngx_resolver_an_t);
 
+        if (len > n - i) {
+            goto short_response;
+        }
+
         switch (type) {
 
         case NGX_RESOLVE_PTR: