4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> commit e7a6994d043a1e31d5b17706a22ce33d2a3e4cdc upstream. If the "struct can_priv::echo_skb" is accessed out of bounds would lead to a kernel crash. Better print a sensible warning message instead and try to recover. Cc: linux-stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/can/dev.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/net/can/dev.c +++ b/drivers/net/can/dev.c @@ -427,7 +427,11 @@ struct sk_buff *__can_get_echo_skb(struc { struct can_priv *priv = netdev_priv(dev); - BUG_ON(idx >= priv->echo_skb_max); + if (idx >= priv->echo_skb_max) { + netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n", + __func__, idx, priv->echo_skb_max); + return NULL; + } if (priv->echo_skb[idx]) { /* Using "struct canfd_frame::len" for the frame