Fix a use-after-free in filemode

In case the TAL of a self-signed is unavailable, cert would be freed but
we'd still hold a reference to its expired time in expires, so invalidate
that pointer as well.

Found by, initial fix and ok job

diff --git a/usr.sbin/rpki-client/filemode.c b/usr.sbin/rpki-client/filemode.c
index b2e729c..2870662 100644 (file)
--- a/usr.sbin/rpki-client/filemode.c
+++ b/usr.sbin/rpki-client/filemode.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: filemode.c,v 1.30 2023/04/26 16:32:41 claudio Exp $ */
+/*     $OpenBSD: filemode.c,v 1.31 2023/05/03 10:22:30 tb Exp $ */
 /*
  * Copyright (c) 2019 Claudio Jeker <claudio@openbsd.org>
  * Copyright (c) 2019 Kristaps Dzonsons <kristaps@bsd.lv>
@@ -478,6 +478,7 @@ proc_parser_file(char *file, unsigned char *buf, size_t len)
                } else {
                        cert_free(cert);
                        cert = NULL;
+                       expires = NULL;
                        status = 0;
                }
        }