releases/3.18.82/tun-allow-positive-return-values-on-dev_get_valid_name-call.patch

   1 From foo@baz Thu Nov 16 15:48:06 CET 2017
   2 From: Julien Gomes <julien@arista.com>
   3 Date: Wed, 25 Oct 2017 11:50:50 -0700
   4 Subject: tun: allow positive return values on dev_get_valid_name() call
   5
   6 From: Julien Gomes <julien@arista.com>
   7
   8
   9 [ Upstream commit 5c25f65fd1e42685f7ccd80e0621829c105785d9 ]
  10
  11 If the name argument of dev_get_valid_name() contains "%d", it will try
  12 to assign it a unit number in __dev__alloc_name() and return either the
  13 unit number (>= 0) or an error code (< 0).
  14 Considering positive values as error values prevent tun device creations
  15 relying this mechanism, therefor we should only consider negative values
  16 as errors here.
  17
  18 Signed-off-by: Julien Gomes <julien@arista.com>
  19 Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
  20 Signed-off-by: David S. Miller <davem@davemloft.net>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22 ---
  23  drivers/net/tun.c |    2 +-
  24  1 file changed, 1 insertion(+), 1 deletion(-)
  25
  26 --- a/drivers/net/tun.c
  27 +++ b/drivers/net/tun.c
  28 @@ -1657,7 +1657,7 @@ static int tun_set_iff(struct net *net,
  29                 if (!dev)
  30                         return -ENOMEM;
  31                 err = dev_get_valid_name(net, dev, name);
  32 -               if (err)
  33 +               if (err < 0)
  34                         goto err_free_dev;
  35
  36                 dev_net_set(dev, net);