1. 15 Dec, 2014 1 commit
    • lucien's avatar
      ip_tunnel: the lack of vti_link_ops' dellink() cause kernel panic · 2c3a8443
      lucien authored
      commit 20ea60ca upstream.
      
      Now the vti_link_ops do not point the .dellink, for fb tunnel device
      (ip_vti0), the net_device will be removed as the default .dellink is
      unregister_netdevice_queue,but the tunnel still in the tunnel list,
      then if we add a new vti tunnel, in ip_tunnel_find():
      
              hlist_for_each_entry_rcu(t, head, hash_node) {
                      if (local == t->parms.iph.saddr &&
                          remote == t->parms.iph.daddr &&
                          link == t->parms.link &&
      ==>                 type == t->dev->type &&
                          ip_tunnel_key_match(&t->parms, flags, key))
                              break;
              }
      
      the panic will happen, cause dev of ip_tunnel *t is null:
      [ 3835.072977] IP: [<ffffffffa04103fd>] ip_tunnel_find+0x9d/0xc0 [ip_tunnel]
      [ 3835.073008] PGD b2c21067 PUD b7277067 PMD 0
      [ 3835.073008] Oops: 0000 [#1] SMP
      .....
      [ 3835.073008] Stack:
      [ 3835.073008]  ffff8800b72d77f0 ffffffffa0411924 ffff8800bb956000 ffff8800b72d78e0
      [ 3835.073008]  ffff8800b72d78a0 0000000000000000 ffffffffa040d100 ffff8800b72d7858
      [ 3835.073008]  ffffffffa040b2e3 0000000000000000 0000000000000000 0000000000000000
      [ 3835.073008] Call Trace:
      [ 3835.073008]  [<ffffffffa0411924>] ip_tunnel_newlink+0x64/0x160 [ip_tunnel]
      [ 3835.073008]  [<ffffffffa040b2e3>] vti_newlink+0x43/0x70 [ip_vti]
      [ 3835.073008]  [<ffffffff8150d4da>] rtnl_newlink+0x4fa/0x5f0
      [ 3835.073008]  [<ffffffff812f68bb>] ? nla_strlcpy+0x5b/0x70
      [ 3835.073008]  [<ffffffff81508fb0>] ? rtnl_link_ops_get+0x40/0x60
      [ 3835.073008]  [<ffffffff8150d11f>] ? rtnl_newlink+0x13f/0x5f0
      [ 3835.073008]  [<ffffffff81509cf4>] rtnetlink_rcv_msg+0xa4/0x270
      [ 3835.073008]  [<ffffffff8126adf5>] ? sock_has_perm+0x75/0x90
      [ 3835.073008]  [<ffffffff81509c50>] ? rtnetlink_rcv+0x30/0x30
      [ 3835.073008]  [<ffffffff81529e39>] netlink_rcv_skb+0xa9/0xc0
      [ 3835.073008]  [<ffffffff81509c48>] rtnetlink_rcv+0x28/0x30
      ....
      
      modprobe ip_vti
      ip link del ip_vti0 type vti
      ip link add ip_vti0 type vti
      rmmod ip_vti
      
      do that one or more times, kernel will panic.
      
      fix it by assigning ip_tunnel_dellink to vti_link_ops' dellink, in
      which we skip the unregister of fb tunnel device. do the same on ip6_vti.
      Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
      Signed-off-by: default avatarCong Wang <cwang@twopensource.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      2c3a8443
  2. 10 Dec, 2014 39 commits