[PATCH 01/10] USB: serial: xr: fix NULL-deref at probe

[Johan Hovold]

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: a8f54b7bd132 ("USB: serial: add MaxLinear/Exar USB to Serial driver")
Signed-off-by: Johan Hovold <jo...@kernel.org>
---
 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 bdb2df27b50b..7be6da6a5cf3 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");
-- 
2.26.2