can: bcm: initialize ifindex for timeouts without previous frame reception

Set in the rx_ifindex to pass the correct interface index in the case of a
message timeout detection. Usually the rx_ifindex value is set at receive
time. But when no CAN frame has been received the RX_TIMEOUT notification
did not contain a valid value.

Cc: linux-stable <stable@vger.kernel.org>
Reported-by: NAndre Naujoks <nautsch2@googlemail.com>
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

net/can/bcm.c

@@ -1084,6 +1084,9 @@ static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
 		op->sk = sk;
 		op->ifindex = ifindex;
 
+		/* ifindex for timeout events w/o previous frame reception */
+		op->rx_ifindex = ifindex;
+
 		/* initialize uninitialized (kzalloc) structure */
 		hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 		op->timer.function = bcm_rx_timeout_handler;