upstream commit

Use explicit_bzero() instead of bzero() before free() to
prevent the compiler from optimizing away the bzero() call.  OK djm@

Upstream-ID: cdc6197e64c9684c7250e23d60863ee1b53cef1d
diff --git a/channels.c b/channels.c
index 72f0e77..89b7d34 100644
--- a/channels.c
+++ b/channels.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: channels.c,v 1.370 2017/09/12 07:55:48 djm Exp $ */
+/* $OpenBSD: channels.c,v 1.371 2017/09/19 12:10:30 millert Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -573,7 +573,7 @@
 	if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
 		c->filter_cleanup(ssh, c->self, c->filter_ctx);
 	sc->channels[c->self] = NULL;
-	bzero(c, sizeof(*c));
+	explicit_bzero(c, sizeof(*c));
 	free(c);
 }