Prevent a use-after-free access in case of a http redirect by also clearing

the conn->res pointer after calling freeaddrinfo().
OK tb@ (as part of a bigger diff)

diff --git a/usr.sbin/rpki-client/http.c b/usr.sbin/rpki-client/http.c
index b3d23cf..771265e 100644 (file)
--- a/usr.sbin/rpki-client/http.c
+++ b/usr.sbin/rpki-client/http.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: http.c,v 1.21 2021/04/07 16:40:38 claudio Exp $  */
+/*      $OpenBSD: http.c,v 1.22 2021/04/08 16:43:08 claudio Exp $  */
 /*
  * Copyright (c) 2020 Nils Fisher <nils_fisher@hotmail.com>
  * Copyright (c) 2020 Claudio Jeker <claudio@openbsd.org>
@@ -526,11 +526,13 @@ http_connect(struct http_connection *conn)
                        warn("%s: %s", http_info(conn->url), cause);
                freeaddrinfo(conn->res0);
                conn->res0 = NULL;
+               conn->res = NULL;
                return -1;
        }
 
        freeaddrinfo(conn->res0);
        conn->res0 = NULL;
+       conn->res = NULL;
 
 #if 0
        /* TODO proxy connect */
@@ -560,6 +562,7 @@ http_finish_connect(struct http_connection *conn)
 
        freeaddrinfo(conn->res0);
        conn->res0 = NULL;
+       conn->res = NULL;
 
 #if 0
        /* TODO proxy connect */