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

Message ID 20210121102922.17439-3-johan@kernel.org (mailing list archive)
State Accepted
Commit a38d21488097f9823ebd297d56b24f431ee7acaa
Headers show
Series USB: serial: xr: fix up remaining issues in new driver | expand

Commit Message

Johan Hovold Jan. 21, 2021, 10:29 a.m. UTC 
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 <johan@kernel.org>
---
 drivers/usb/serial/xr_serial.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox series

Patch

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");