releases/4.6.6/can-fix-handling-of-unmodifiable-configuration-options-fix.patch

   1 From bce271f255dae8335dc4d2ee2c4531e09cc67f5a Mon Sep 17 00:00:00 2001
   2 From: Oliver Hartkopp <socketcan@hartkopp.net>
   3 Date: Tue, 21 Jun 2016 12:14:07 +0200
   4 Subject: can: fix handling of unmodifiable configuration options fix
   5
   6 From: Oliver Hartkopp <socketcan@hartkopp.net>
   7
   8 commit bce271f255dae8335dc4d2ee2c4531e09cc67f5a upstream.
   9
  10 With upstream commit bb208f144cf3f59 (can: fix handling of unmodifiable
  11 configuration options) a new can_validate() function was introduced.
  12
  13 When invoking 'ip link set can0 type can' without any configuration data
  14 can_validate() tries to validate the content without taking into account that
  15 there's totally no content. This patch adds a check for missing content.
  16
  17 Reported-by: ajneu <ajneu1@gmail.com>
  18 Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
  19 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
  20 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  21
  22 ---
  23  drivers/net/can/dev.c |    3 +++
  24  1 file changed, 3 insertions(+)
  25
  26 --- a/drivers/net/can/dev.c
  27 +++ b/drivers/net/can/dev.c
  28 @@ -798,6 +798,9 @@ static int can_validate(struct nlattr *t
  29          * - control mode with CAN_CTRLMODE_FD set
  30          */
  31
  32 +       if (!data)
  33 +               return 0;
  34 +
  35         if (data[IFLA_CAN_CTRLMODE]) {
  36                 struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
  37