From a38d21488097f9823ebd297d56b24f431ee7acaa Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Thu, 21 Jan 2021 11:29:13 +0100 Subject: [PATCH] USB: serial: xr: fix NULL-deref at probe Make sure that the probed device has an interface 0 to avoid dereferencing a NULL pointer in case of a malicious device or during USB-descriptor fuzzing. Fixes: c2d405aa86b4 ("USB: serial: add MaxLinear/Exar USB to Serial driver") Signed-off-by: Johan Hovold --- drivers/usb/serial/xr_serial.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/serial/xr_serial.c b/drivers/usb/serial/xr_serial.c index bdb2df27b50bf..7be6da6a5cf3e 100644 --- a/drivers/usb/serial/xr_serial.c +++ b/drivers/usb/serial/xr_serial.c @@ -552,6 +552,9 @@ static int xr_probe(struct usb_serial *serial, const struct usb_device_id *id) /* But claim the control interface during data interface probe */ control_interface = usb_ifnum_to_if(usb_dev, 0); + if (!control_interface) + return -ENODEV; + ret = usb_driver_claim_interface(driver, control_interface, NULL); if (ret) { dev_err(&serial->interface->dev, "Failed to claim control interface\n"); -- 2.30.2