[src/trunk]: src/sys/netinet Remove wrong KASSERT in arptfree

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

details:   https://anonhg.NetBSD.org/src/rev/c697ed6b24d1
branches:  trunk
changeset: 340498:c697ed6b24d1
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Wed Sep 09 01:24:01 2015 +0000

description:
Remove wrong KASSERT in arptfree

la_rt can be NULL because arptimer that calls arptfree doesn't always
free llentry so llentry can remain with la_rt == NULL. So we instead
check whether la_rt is NULL or not and do arptfree if not.

This fixes PR kern/50184 (confirmed by martin@) and
PR kern/50186 (maybe).

diffstat:

 sys/netinet/if_arp.c |  24 ++++++++++--------------
 1 files changed, 10 insertions(+), 14 deletions(-)

diffs (62 lines):

diff -r d6c946172eaa -r c697ed6b24d1 sys/netinet/if_arp.c
--- a/sys/netinet/if_arp.c      Wed Sep 09 01:22:28 2015 +0000
+++ b/sys/netinet/if_arp.c      Wed Sep 09 01:24:01 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_arp.c,v 1.179 2015/09/09 01:22:28 ozaki-r Exp $     */
+/*     $NetBSD: if_arp.c,v 1.180 2015/09/09 01:24:01 ozaki-r Exp $     */
 
 /*-
  * Copyright (c) 1998, 2000, 2008 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.179 2015/09/09 01:22:28 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.180 2015/09/09 01:24:01 ozaki-r Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -159,7 +159,7 @@
 
 static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *,
            const struct sockaddr *);
-static void arptfree(struct llentry *);
+static void arptfree(struct rtentry *);
 static void arptimer(void *);
 static struct llentry *arplookup(struct ifnet *, struct mbuf *,
            const struct in_addr *, int, int, int, struct rtentry *);
@@ -351,8 +351,11 @@
        /* XXX: LOR avoidance. We still have ref on lle. */
        LLE_WUNLOCK(lle);
 
-       /* We have to call this w/o lock */
-       arptfree(lle);
+       if (lle->la_rt != NULL) {
+               /* We have to call arptfree w/o IF_AFDATA_LOCK */
+               arptfree(lle->la_rt);
+               lle->la_rt = NULL;
+       }
 
        IF_AFDATA_LOCK(ifp);
        LLE_WLOCK(lle);
@@ -1423,18 +1426,11 @@
 /*
  * Free an arp entry.
  */
-static void arptfree(struct llentry *la)
+static void arptfree(struct rtentry *rt)
 {
-       struct rtentry *rt = la->la_rt;
-
-       KASSERT(rt != NULL);
-
-       if (la->la_rt != NULL) {
-               rtfree(la->la_rt);
-               la->la_rt = NULL;
-       }
 
        rtrequest(RTM_DELETE, rt_getkey(rt), NULL, rt_mask(rt), 0, NULL);
+       rtfree(rt);
 }
 
 /*