git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From e7a6994d043a1e31d5b17706a22ce33d2a3e4cdc Mon Sep 17 00:00:00 2001
   2 From: Marc Kleine-Budde <mkl@pengutronix.de>
   3 Date: Wed, 31 Oct 2018 14:05:26 +0100
   4 Subject: can: dev: __can_get_echo_skb(): Don't crash the kernel if can_priv::echo_skb is accessed out of bounds
   5
   6 From: Marc Kleine-Budde <mkl@pengutronix.de>
   7
   8 commit e7a6994d043a1e31d5b17706a22ce33d2a3e4cdc upstream.
   9
  10 If the "struct can_priv::echo_skb" is accessed out of bounds would lead
  11 to a kernel crash. Better print a sensible warning message instead and
  12 try to recover.
  13
  14 Cc: linux-stable <stable@vger.kernel.org>
  15 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
  16 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  17
  18 ---
  19  drivers/net/can/dev.c |    6 +++++-
  20  1 file changed, 5 insertions(+), 1 deletion(-)
  21
  22 --- a/drivers/net/can/dev.c
  23 +++ b/drivers/net/can/dev.c
  24 @@ -481,7 +481,11 @@ struct sk_buff *__can_get_echo_skb(struc
  25  {
  26         struct can_priv *priv = netdev_priv(dev);
  27
  28 -       BUG_ON(idx >= priv->echo_skb_max);
  29 +       if (idx >= priv->echo_skb_max) {
  30 +               netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
  31 +                          __func__, idx, priv->echo_skb_max);
  32 +               return NULL;
  33 +       }
  34
  35         if (priv->echo_skb[idx]) {
  36                 /* Using "struct canfd_frame::len" for the frame