[src/trunk]: src/sys/netinet6 Correct sanity checks of icmp6_redirect_output

[ozaki-r <ozaki-r%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/09f88106d0ed
branches:  trunk
changeset: 349463:09f88106d0ed
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Sun Dec 11 07:35:42 2016 +0000

description:
Correct sanity checks of icmp6_redirect_output

- rt->rt_ifp is always non-NULL
- Checking RTF_UP here is just racy and meaningless
- The arguments should be non-NULL (at least for now)

diffstat:

 sys/netinet6/icmp6.c |  10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diffs (31 lines):

diff -r a54c7db7171c -r 09f88106d0ed sys/netinet6/icmp6.c
--- a/sys/netinet6/icmp6.c      Sun Dec 11 07:34:14 2016 +0000
+++ b/sys/netinet6/icmp6.c      Sun Dec 11 07:35:42 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: icmp6.c,v 1.201 2016/11/15 20:50:28 mlelstv Exp $      */
+/*     $NetBSD: icmp6.c,v 1.202 2016/12/11 07:35:42 ozaki-r Exp $      */
 /*     $KAME: icmp6.c,v 1.217 2001/06/20 15:03:29 jinmei Exp $ */
 
 /*
@@ -62,7 +62,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: icmp6.c,v 1.201 2016/11/15 20:50:28 mlelstv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: icmp6.c,v 1.202 2016/12/11 07:35:42 ozaki-r Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -2421,8 +2421,10 @@
                goto fail;
 
        /* sanity check */
-       if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
-               goto fail;
+       KASSERT(m0 != NULL);
+       KASSERT(rt != NULL);
+
+       ifp = rt->rt_ifp;
 
        /*
         * Address check: