net: can: esd_usb2: check index of array before accessing

The esd_usb2_read_bulk_callback() function is parsing the data that comes from
the USB CAN adapter. One datum is used as an index to access the dev->nets[]
array. This patch adds the missing bounds checking.

Acked-by: Matthias Fuchs <matthias.fuchs@esd.eu>
Signed-off-by: Maximilian Schneider <max@schneidersoft.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/net/can/usb/esd_usb2.c b/drivers/net/can/usb/esd_usb2.c
index 6aa7b3266c80..ac6177d3befc 100644
--- a/drivers/net/can/usb/esd_usb2.c
+++ b/drivers/net/can/usb/esd_usb2.c
@@ -412,10 +412,20 @@ static void esd_usb2_read_bulk_callback(struct urb *urb)
 
                 switch (msg->msg.hdr.cmd) {
                 case CMD_CAN_RX:
+                        if (msg->msg.rx.net >= dev->net_count) {
+                                dev_err(dev->udev->dev.parent, "format error\n");
+                                break;
+                        }
+
                         esd_usb2_rx_can_msg(dev->nets[msg->msg.rx.net], msg);
                         break;
 
                 case CMD_CAN_TX:
+                        if (msg->msg.txdone.net >= dev->net_count) {
+                                dev_err(dev->udev->dev.parent, "format error\n");
+                                break;
+                        }
+
                         esd_usb2_tx_done_msg(dev->nets[msg->msg.txdone.net],
                                              msg);
                         break;