[src/trunk]: src/sys/dev/wscons wsevent_copyout_events50 - don't leak garbage...

[uwe <uwe%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e7d6b2979ab2
branches:  trunk
changeset: 319824:e7d6b2979ab2
user:      uwe <uwe%NetBSD.org@localhost>
date:      Wed Jun 13 02:09:09 2018 +0000

description:
wsevent_copyout_events50 - don't leak garbage from the kernel stack.

On 64-bit machines struct timespec50 has padding between 32-bit tv_sec
and long tv_nsec that is not affected by normal assignment.  Scrub it
before we uiomove struct owscons_event.

diffstat:

 sys/dev/wscons/wsevent.c |  7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diffs (28 lines):

diff -r b54be3497aad -r e7d6b2979ab2 sys/dev/wscons/wsevent.c
--- a/sys/dev/wscons/wsevent.c  Wed Jun 13 00:24:07 2018 +0000
+++ b/sys/dev/wscons/wsevent.c  Wed Jun 13 02:09:09 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: wsevent.c,v 1.37 2017/10/25 08:12:39 maya Exp $ */
+/* $NetBSD: wsevent.c,v 1.38 2018/06/13 02:09:09 uwe Exp $ */
 
 /*-
  * Copyright (c) 2006, 2008 The NetBSD Foundation, Inc.
@@ -104,7 +104,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: wsevent.c,v 1.37 2017/10/25 08:12:39 maya Exp $");
+__KERNEL_RCSID(0, "$NetBSD: wsevent.c,v 1.38 2018/06/13 02:09:09 uwe Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_compat_netbsd.h"
@@ -202,6 +202,9 @@
 
                ev50.type = ev->type;
                ev50.value = ev->value;
+#if INT32_MAX < LONG_MAX       /* scrub padding */
+               memset(&ev50.time, 0, offsetof(struct timespec50, tv_nsec));
+#endif
                timespec_to_timespec50(&ev->time, &ev50.time);
 
                error = uiomove(&ev50, sizeof(ev50), uio);