commit b5bd6cdee51bde6976a3ab52660a6a154471a68b
author Maxim Dounin <mdounin@mdounin.ru> Tue May 25 15:17:36 2021 +0300
committer Maxim Dounin <mdounin@mdounin.ru> Tue May 25 15:17:36 2021 +0300
tree 1238d8b9f276604027f1eff2b2e6a917f10bc962
parent 0c5e1100a4efe26a07ac3ac46ac056a5c4520e85

Resolver: fixed off-by-one write in ngx_resolver_copy().

Reported by Luis Merino, Markus Vervier, Eric Sesterhenn, X41 D-Sec GmbH.

src/core/ngx_resolver.c

diff --git a/src/core/ngx_resolver.c b/src/core/ngx_resolver.c
index 7939070..63b2619 100644
--- a/src/core/ngx_resolver.c
+++ b/src/core/ngx_resolver.c
@@ -4008,15 +4008,15 @@
             n = *src++;
 
         } else {
+            if (dst != name->data) {
+                *dst++ = '.';
+            }
+
             ngx_strlow(dst, src, n);
             dst += n;
             src += n;
 
             n = *src++;
-
-            if (n != 0) {
-                *dst++ = '.';
-            }
         }
 
         if (n == 0) {