[src/trunk]: src/sys/net fix vlan panic when vlan is re-configured without de...

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

details:   https://anonhg.NetBSD.org/src/rev/e871c0d7e12f
branches:  trunk
changeset: 356887:e871c0d7e12f
user:      knakahara <knakahara%NetBSD.org@localhost>
date:      Thu Oct 19 07:02:00 2017 +0000

description:
fix vlan panic when vlan is re-configured without destroy.

E.g. the following operation causes this panic.
    ====================
    # ifconfig vlan0 create
    # ifconfig vlan0 vlan 1 vlanif ixg3
    # ifconfig vlan1 create
    # ifconfig vlan1 vlan 1 vlanif ixg2
    # ifconfig vlan1 -vlanif
    # ifconfig vlan1 vlan 1 vlanif ixg2

    panic: kernel diagnostic assertion "new->ple_next == NULL" failed: file "/git/netbsd-src/sys/sys/pslist.h", line 118
    ====================

Pointed out and tested by msaitoh@n.o, fixed by s-yamaguchi@IIJ, thanks.

XXX need pullup-8

diffstat:

 sys/net/if_vlan.c |  6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diffs (34 lines):

diff -r 8f77983670df -r e871c0d7e12f sys/net/if_vlan.c
--- a/sys/net/if_vlan.c Thu Oct 19 06:29:16 2017 +0000
+++ b/sys/net/if_vlan.c Thu Oct 19 07:02:00 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_vlan.c,v 1.103 2017/10/12 02:40:59 ozaki-r Exp $    */
+/*     $NetBSD: if_vlan.c,v 1.104 2017/10/19 07:02:00 knakahara Exp $  */
 
 /*-
  * Copyright (c) 2000, 2001 The NetBSD Foundation, Inc.
@@ -78,7 +78,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_vlan.c,v 1.103 2017/10/12 02:40:59 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_vlan.c,v 1.104 2017/10/19 07:02:00 knakahara Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -478,6 +478,7 @@
         */
        ifv->ifv_if.if_type = p->if_type;
 
+       PSLIST_ENTRY_INIT(ifv, ifv_hash);
        idx = tag_hash_func(tag, ifv_hash.mask);
 
        mutex_enter(&ifv_hash.lock);
@@ -582,6 +583,7 @@
        PSLIST_WRITER_REMOVE(ifv, ifv_hash);
        pserialize_perform(vlan_psz);
        mutex_exit(&ifv_hash.lock);
+       PSLIST_ENTRY_DESTROY(ifv, ifv_hash);
 
        vlan_linkmib_update(ifv, nmib);