diff options
| author | Nicolas Dichtel <nicolas.dichtel@6wind.com> | 2014-01-31 09:24:04 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-06 11:08:17 -0800 |
| commit | 1b2a58ff62aa3acc7c539b325972c9b94ce89c3d (patch) | |
| tree | d7de397846cae09a2b8b9d46eef4be6844db80d1 /net | |
| parent | 64cee83a9856e8fa4cb6616a072469d5eba3c1d7 (diff) | |
sit: fix double free of fb_tunnel_dev on exit
[ No relevant upstream commit. ]
This problem was fixed upstream by commit 9434266f2c64 ("sit: fix use after free
of fb_tunnel_dev").
The upstream patch depends on upstream commit 5e6700b3bf98 ("sit: add support of
x-netns"), which was not backported into 3.10 branch.
First, explain the problem: when the sit module is unloaded, sit_cleanup() is
called.
rmmod sit
=> sit_cleanup()
=> rtnl_link_unregister()
=> __rtnl_kill_links()
=> for_each_netdev(net, dev) {
if (dev->rtnl_link_ops == ops)
ops->dellink(dev, &list_kill);
}
At this point, the FB device is deleted (and all sit tunnels).
=> unregister_pernet_device()
=> unregister_pernet_operations()
=> ops_exit_list()
=> sit_exit_net()
=> sit_destroy_tunnels()
In this function, no tunnel is found.
=> unregister_netdevice_queue(sitn->fb_tunnel_dev, &list);
We delete the FB device a second time here!
Because we cannot simply remove the second deletion (sit_exit_net() must remove
the FB device when a netns is deleted), we add an rtnl ops which delete all sit
device excepting the FB device and thus we can keep the explicit deletion in
sit_exit_net().
CC: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Reported-by: Steven Rostedt <srostedt@redhat.com>
Tested-by: Steven Rostedt <srostedt@redhat.com> (and our entire MRG team)
Tested-by: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Tested-by: John Kacur <jkacur@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv6/sit.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c index 0491264b8bf..620d326e8fd 100644 --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -1507,6 +1507,15 @@ static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = { #endif }; +static void ipip6_dellink(struct net_device *dev, struct list_head *head) +{ + struct net *net = dev_net(dev); + struct sit_net *sitn = net_generic(net, sit_net_id); + + if (dev != sitn->fb_tunnel_dev) + unregister_netdevice_queue(dev, head); +} + static struct rtnl_link_ops sit_link_ops __read_mostly = { .kind = "sit", .maxtype = IFLA_IPTUN_MAX, @@ -1517,6 +1526,7 @@ static struct rtnl_link_ops sit_link_ops __read_mostly = { .changelink = ipip6_changelink, .get_size = ipip6_get_size, .fill_info = ipip6_fill_info, + .dellink = ipip6_dellink, }; static struct xfrm_tunnel sit_handler __read_mostly = { |