linux-stable/net/tipc/core.c
Xin Long c492d4c74d tipc: change to use register_pernet_device
This patch is to fix a dst defcnt leak, which can be reproduced by doing:

  # ip net a c; ip net a s; modprobe tipc
  # ip net e s ip l a n eth1 type veth peer n eth1 netns c
  # ip net e c ip l s lo up; ip net e c ip l s eth1 up
  # ip net e s ip l s lo up; ip net e s ip l s eth1 up
  # ip net e c ip a a 1.1.1.2/8 dev eth1
  # ip net e s ip a a 1.1.1.1/8 dev eth1
  # ip net e c tipc b e m udp n u1 localip 1.1.1.2
  # ip net e s tipc b e m udp n u1 localip 1.1.1.1
  # ip net d c; ip net d s; rmmod tipc

and it will get stuck and keep logging the error:

  unregister_netdevice: waiting for lo to become free. Usage count = 1

The cause is that a dst is held by the udp sock's sk_rx_dst set on udp rx
path with udp_early_demux == 1, and this dst (eventually holding lo dev)
can't be released as bearer's removal in tipc pernet .exit happens after
lo dev's removal, default_device pernet .exit.

 "There are two distinct types of pernet_operations recognized: subsys and
  device.  At creation all subsys init functions are called before device
  init functions, and at destruction all device exit functions are called
  before subsys exit function."

So by calling register_pernet_device instead to register tipc_net_ops, the
pernet .exit() will be invoked earlier than loopback dev's removal when a
netns is being destroyed, as fou/gue does.

Note that vxlan and geneve udp tunnels don't have this issue, as the udp
sock is released in their device ndo_stop().

This fix is also necessary for tipc dst_cache, which will hold dsts on tx
path and I will introduce in my next patch.

Reported-by: Li Shuang <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-22 16:51:47 -07:00

190 lines
4.9 KiB
C

/*
* net/tipc/core.c: TIPC module code
*
* Copyright (c) 2003-2006, 2013, Ericsson AB
* Copyright (c) 2005-2006, 2010-2013, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include "core.h"
#include "name_table.h"
#include "subscr.h"
#include "bearer.h"
#include "net.h"
#include "socket.h"
#include "bcast.h"
#include "node.h"
#include <linux/module.h>
/* configurable TIPC parameters */
unsigned int tipc_net_id __read_mostly;
int sysctl_tipc_rmem[3] __read_mostly; /* min/default/max */
static int __net_init tipc_init_net(struct net *net)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
int err;
tn->net_id = 4711;
tn->node_addr = 0;
tn->trial_addr = 0;
tn->addr_trial_end = 0;
tn->capabilities = TIPC_NODE_CAPABILITIES;
memset(tn->node_id, 0, sizeof(tn->node_id));
memset(tn->node_id_string, 0, sizeof(tn->node_id_string));
tn->mon_threshold = TIPC_DEF_MON_THRESHOLD;
get_random_bytes(&tn->random, sizeof(int));
INIT_LIST_HEAD(&tn->node_list);
spin_lock_init(&tn->node_list_lock);
err = tipc_sk_rht_init(net);
if (err)
goto out_sk_rht;
err = tipc_nametbl_init(net);
if (err)
goto out_nametbl;
INIT_LIST_HEAD(&tn->dist_queue);
err = tipc_bcast_init(net);
if (err)
goto out_bclink;
return 0;
out_bclink:
tipc_nametbl_stop(net);
out_nametbl:
tipc_sk_rht_destroy(net);
out_sk_rht:
return err;
}
static void __net_exit tipc_exit_net(struct net *net)
{
tipc_net_stop(net);
tipc_bcast_stop(net);
tipc_nametbl_stop(net);
tipc_sk_rht_destroy(net);
}
static struct pernet_operations tipc_net_ops = {
.init = tipc_init_net,
.exit = tipc_exit_net,
.id = &tipc_net_id,
.size = sizeof(struct tipc_net),
};
static struct pernet_operations tipc_topsrv_net_ops = {
.init = tipc_topsrv_init_net,
.exit = tipc_topsrv_exit_net,
};
static int __init tipc_init(void)
{
int err;
pr_info("Activated (version " TIPC_MOD_VER ")\n");
sysctl_tipc_rmem[0] = RCVBUF_MIN;
sysctl_tipc_rmem[1] = RCVBUF_DEF;
sysctl_tipc_rmem[2] = RCVBUF_MAX;
err = tipc_netlink_start();
if (err)
goto out_netlink;
err = tipc_netlink_compat_start();
if (err)
goto out_netlink_compat;
err = tipc_register_sysctl();
if (err)
goto out_sysctl;
err = register_pernet_device(&tipc_net_ops);
if (err)
goto out_pernet;
err = tipc_socket_init();
if (err)
goto out_socket;
err = register_pernet_device(&tipc_topsrv_net_ops);
if (err)
goto out_pernet_topsrv;
err = tipc_bearer_setup();
if (err)
goto out_bearer;
pr_info("Started in single node mode\n");
return 0;
out_bearer:
unregister_pernet_device(&tipc_topsrv_net_ops);
out_pernet_topsrv:
tipc_socket_stop();
out_socket:
unregister_pernet_device(&tipc_net_ops);
out_pernet:
tipc_unregister_sysctl();
out_sysctl:
tipc_netlink_compat_stop();
out_netlink_compat:
tipc_netlink_stop();
out_netlink:
pr_err("Unable to start in single node mode\n");
return err;
}
static void __exit tipc_exit(void)
{
tipc_bearer_cleanup();
unregister_pernet_device(&tipc_topsrv_net_ops);
tipc_socket_stop();
unregister_pernet_device(&tipc_net_ops);
tipc_netlink_stop();
tipc_netlink_compat_stop();
tipc_unregister_sysctl();
pr_info("Deactivated\n");
}
module_init(tipc_init);
module_exit(tipc_exit);
MODULE_DESCRIPTION("TIPC: Transparent Inter Process Communication");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_VERSION(TIPC_MOD_VER);