queue-4.4/team-fix-possible-recursive-locking-when-add-slaves.patch

   1 From foo@baz Tue 30 Apr 2019 11:47:03 AM CEST
   2 From: Hangbin Liu <liuhangbin@gmail.com>
   3 Date: Fri, 19 Apr 2019 14:31:00 +0800
   4 Subject: team: fix possible recursive locking when add slaves
   5
   6 From: Hangbin Liu <liuhangbin@gmail.com>
   7
   8 [ Upstream commit 925b0c841e066b488cc3a60272472b2c56300704 ]
   9
  10 If we add a bond device which is already the master of the team interface,
  11 we will hold the team->lock in team_add_slave() first and then request the
  12 lock in team_set_mac_address() again. The functions are called like:
  13
  14 - team_add_slave()
  15  - team_port_add()
  16    - team_port_enter()
  17      - team_modeop_port_enter()
  18        - __set_port_dev_addr()
  19          - dev_set_mac_address()
  20            - bond_set_mac_address()
  21              - dev_set_mac_address()
  22                - team_set_mac_address
  23
  24 Although team_upper_dev_link() would check the upper devices but it is
  25 called too late. Fix it by adding a checking before processing the slave.
  26
  27 v2: Do not split the string in netdev_err()
  28
  29 Fixes: 3d249d4ca7d0 ("net: introduce ethernet teaming device")
  30 Acked-by: Jiri Pirko <jiri@mellanox.com>
  31 Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
  32 Signed-off-by: David S. Miller <davem@davemloft.net>
  33 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  34 ---
  35  drivers/net/team/team.c |    6 ++++++
  36  1 file changed, 6 insertions(+)
  37
  38 --- a/drivers/net/team/team.c
  39 +++ b/drivers/net/team/team.c
  40 @@ -1136,6 +1136,12 @@ static int team_port_add(struct team *te
  41                 return -EINVAL;
  42         }
  43
  44 +       if (netdev_has_upper_dev(dev, port_dev)) {
  45 +               netdev_err(dev, "Device %s is already an upper device of the team interface\n",
  46 +                          portname);
  47 +               return -EBUSY;
  48 +       }
  49 +
  50         if (port_dev->features & NETIF_F_VLAN_CHALLENGED &&
  51             vlan_uses_dev(dev)) {
  52                 netdev_err(dev, "Device %s is VLAN challenged and team device has VLAN set up\n",