From 9cb6cb7ed11cd3b69c47bb414983603a6ff20b1d Mon Sep 17 00:00:00 2001 From: Zang MingJie Date: Wed, 6 Mar 2013 04:37:37 +0000 Subject: [PATCH] vxlan: fix oops when delete netns containing vxlan The following script will produce a kernel oops: sudo ip netns add v sudo ip netns exec v ip ad add 127.0.0.1/8 dev lo sudo ip netns exec v ip link set lo up sudo ip netns exec v ip ro add 224.0.0.0/4 dev lo sudo ip netns exec v ip li add vxlan0 type vxlan id 42 group 239.1.1.1 dev lo sudo ip netns exec v ip link set vxlan0 up sudo ip netns del v where inspect by gdb: Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 107] 0xffffffffa0289e33 in ?? () (gdb) bt #0 vxlan_leave_group (dev=0xffff88001bafa000) at drivers/net/vxlan.c:533 #1 vxlan_stop (dev=0xffff88001bafa000) at drivers/net/vxlan.c:1087 #2 0xffffffff812cc498 in __dev_close_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:1299 #3 0xffffffff812cd920 in dev_close_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:1335 #4 0xffffffff812cef31 in rollback_registered_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:4851 #5 0xffffffff812cf040 in unregister_netdevice_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:5752 #6 0xffffffff812cf1ba in default_device_exit_batch (net_list=0xffff88001f2e7e18) at net/core/dev.c:6170 #7 0xffffffff812cab27 in cleanup_net (work=) at net/core/net_namespace.c:302 #8 0xffffffff810540ef in process_one_work (worker=0xffff88001ba9ed40, work=0xffffffff8167d020) at kernel/workqueue.c:2157 #9 0xffffffff810549d0 in worker_thread (__worker=__worker@entry=0xffff88001ba9ed40) at kernel/workqueue.c:2276 #10 0xffffffff8105870c in kthread (_create=0xffff88001f2e5d68) at kernel/kthread.c:168 #11 #12 0x0000000000000000 in ?? () #13 0x0000000000000000 in ?? () (gdb) fr 0 #0 vxlan_leave_group (dev=0xffff88001bafa000) at drivers/net/vxlan.c:533 533 struct sock *sk = vn->sock->sk; (gdb) l 528 static int vxlan_leave_group(struct net_device *dev) 529 { 530 struct vxlan_dev *vxlan = netdev_priv(dev); 531 struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id); 532 int err = 0; 533 struct sock *sk = vn->sock->sk; 534 struct ip_mreqn mreq = { 535 .imr_multiaddr.s_addr = vxlan->gaddr, 536 .imr_ifindex = vxlan->link, 537 }; (gdb) p vn->sock $4 = (struct socket *) 0x0 The kernel calls `vxlan_exit_net` when deleting the netns before shutting down vxlan interfaces. Later the removal of all vxlan interfaces, where `vn->sock` is already gone causes the oops. so we should manually shutdown all interfaces before deleting `vn->sock` as the patch does. Signed-off-by: Zang MingJie Signed-off-by: David S. Miller --- drivers/net/vxlan.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index c3e3d2929ee34c..7cee7a3068ec11 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1506,6 +1506,14 @@ static __net_init int vxlan_init_net(struct net *net) static __net_exit void vxlan_exit_net(struct net *net) { struct vxlan_net *vn = net_generic(net, vxlan_net_id); + struct vxlan_dev *vxlan; + unsigned h; + + rtnl_lock(); + for (h = 0; h < VNI_HASH_SIZE; ++h) + hlist_for_each_entry(vxlan, &vn->vni_list[h], hlist) + dev_close(vxlan->dev); + rtnl_unlock(); if (vn->sock) { sk_release_kernel(vn->sock->sk);