Avoid leaking memory if tls_config_set_alpn() is called multiple times

(this was in the original commit, but got reverted in the recommit).

1 files changed, 5 insertions, 4 deletions

diff --git a/src/lib/libtls/tls_config.c b/src/lib/libtls/tls_config.c
index cd2a04cdd6..0d52704aa8 100644
--- a/src/lib/libtls/tls_config.c
+++ b/src/lib/libtls/tls_config.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls_config.c,v 1.26 2016/08/13 13:05:51 jsing Exp $ */
+/* $OpenBSD: tls_config.c,v 1.27 2016/08/13 13:15:53 jsing Exp $ */
 /*
  * Copyright (c) 2014 Joel Sing <jsing@openbsd.org>
  *
@@ -311,6 +311,10 @@ tls_config_parse_alpn(struct tls_config *config, const char *alpn,
         char *s = NULL;
         char *p, *q;
 
+        free(*alpn_data);
+        *alpn_data = NULL;
+        *alpn_len = 0;
+
         if ((buf_len = strlen(alpn) + 1) > 65535) {
                 tls_config_set_errorx(config, "alpn too large");
                 goto err;
@@ -355,9 +359,6 @@ tls_config_parse_alpn(struct tls_config *config, const char *alpn,
         free(buf);
         free(s);
 
-        *alpn_data = NULL;
-        *alpn_len = 0;
-
         return (-1);
 }