[src/trunk]: src/sys/altq sys/altq: Memset zero before copyout.

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

details:   https://anonhg.NetBSD.org/src/rev/ba39ae74491c
branches:  trunk
changeset: 1023229:ba39ae74491c
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Mon Aug 30 08:40:31 2021 +0000

description:
sys/altq: Memset zero before copyout.

Just in case of uninitialized padding which would lead to kernel
stack disclosure.  If the compiler can prove the memset redundant
then it can optimize it away; otherwise better safe than sorry.

diffstat:

 sys/altq/altq_hfsc.c |  5 +++--
 sys/altq/altq_priq.c |  7 +++----
 2 files changed, 6 insertions(+), 6 deletions(-)

diffs (56 lines):

diff -r 320a6c8d3016 -r ba39ae74491c sys/altq/altq_hfsc.c
--- a/sys/altq/altq_hfsc.c      Mon Aug 30 08:40:00 2021 +0000
+++ b/sys/altq/altq_hfsc.c      Mon Aug 30 08:40:31 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: altq_hfsc.c,v 1.28 2018/11/15 10:23:55 maxv Exp $      */
+/*     $NetBSD: altq_hfsc.c,v 1.29 2021/08/30 08:40:31 riastradh Exp $ */
 /*     $KAME: altq_hfsc.c,v 1.26 2005/04/13 03:44:24 suz Exp $ */
 
 /*
@@ -43,7 +43,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: altq_hfsc.c,v 1.28 2018/11/15 10:23:55 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: altq_hfsc.c,v 1.29 2021/08/30 08:40:31 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_altq.h"
@@ -2182,6 +2182,7 @@
        usp = ap->stats;
        for (n = 0; cl != NULL && n < nclasses; cl = hfsc_nextclass(cl), n++) {
 
+               memset(&stats, 0, sizeof(stats));
                get_class_stats(&stats, cl);
 
                if ((error = copyout((void *)&stats, (void *)usp++,
diff -r 320a6c8d3016 -r ba39ae74491c sys/altq/altq_priq.c
--- a/sys/altq/altq_priq.c      Mon Aug 30 08:40:00 2021 +0000
+++ b/sys/altq/altq_priq.c      Mon Aug 30 08:40:31 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: altq_priq.c,v 1.26 2018/11/15 10:23:55 maxv Exp $      */
+/*     $NetBSD: altq_priq.c,v 1.27 2021/08/30 08:40:31 riastradh Exp $ */
 /*     $KAME: altq_priq.c,v 1.13 2005/04/13 03:44:25 suz Exp $ */
 /*
  * Copyright (C) 2000-2003
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: altq_priq.c,v 1.26 2018/11/15 10:23:55 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: altq_priq.c,v 1.27 2021/08/30 08:40:31 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_altq.h"
@@ -958,10 +958,9 @@
        usp = ap->stats;
        for (pri = 0; pri <= pif->pif_maxpri; pri++) {
                cl = pif->pif_classes[pri];
+               memset(&stats, 0, sizeof(stats));
                if (cl != NULL)
                        get_class_stats(&stats, cl);
-               else
-                       memset(&stats, 0, sizeof(stats));
                if ((error = copyout((void *)&stats, (void *)usp++,
                                     sizeof(stats))) != 0)
                        return (error);