Subject: Re: gre_output() issue.
To: David Young <firstname.lastname@example.org>
From: Sean Boudreau <email@example.com>
Date: 08/14/2007 09:42:13
On Tue, Aug 14, 2007 at 01:50:44AM -0400, David Young wrote:
> On Mon, Aug 13, 2007 at 04:43:21PM -0400, Sean Boudreau wrote:
> > Hi:
> > gre_output() isn't checking IFF_RUNNING | IFF_UP
> > properly. The interesting case is when gre_compute_route()
> > fails and IFF_RUNNING is knocked down but IFF_UP is left
> > set. A recursion lock up can result.
> > Any objections before I commit?
> No objections. Can you say more about the recursion lock-up?
You could reproduce the issue as follows where the inner and
outer addrs are the same. This would cause my 3.1 box to
reboot. My 4.0 box would lock hard: probably some spin scenario
after the refactoring to a separate kthread...
# ifconfig -a
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 33192
inet 127.0.0.1 netmask 0xff000000
inet6 ::1 prefixlen 128
inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1
# route flush > /dev/null
# ifconfig gre0 create
# ifconfig gre0 126.96.36.199 188.8.131.52
# ifconfig gre0 tunnel 184.108.40.206 220.127.116.11
# ping -n 18.104.22.168