can: usb: f81604: handle short interrupt urb messages properly

If an interrupt urb is received that is not the correct length, properly
detect it and don't attempt to treat the data as valid.

Cc: Ji-Ze Hong (Peter Hong) <peter_hong@fintek.com.tw>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Vincent Mailhol <mailhol@kernel.org>
Cc: stable@kernel.org
Assisted-by: gkh_clanker_2000
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/2026022331-opal-evaluator-a928@gregkh
Fixes: 88da174 ("can: usb: f81604: add Fintek F81604 support")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Author: gregkh

drivers/net/can/usb/f81604.c

@@ -620,6 +620,12 @@ static void f81604_read_int_callback(struct urb *urb)
 		netdev_info(netdev, "%s: Int URB aborted: %pe\n", __func__,
 			    ERR_PTR(urb->status));
 
+	if (urb->actual_length < sizeof(*data)) {
+		netdev_warn(netdev, "%s: short int URB: %u < %zu\n",
+			    __func__, urb->actual_length, sizeof(*data));
+		goto resubmit_urb;
+	}
+
 	switch (urb->status) {
 	case 0: /* success */
 		break;