usb: yurex: fix race in probe

The bbu member of the descriptor must be set to the value
standing for uninitialized values before the URB whose
completion handler sets bbu is submitted. Otherwise there is
a window during which probing can overwrite already retrieved
data.

Cc: stable <stable@kernel.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Link: https://patch.msgid.link/20260209143720.1507500-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: oneukum

drivers/usb/misc/yurex.c

@@ -272,6 +272,7 @@ static int yurex_probe(struct usb_interface *interface, const struct usb_device_
 			 dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
 			 dev, 1);
 	dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+	dev->bbu = -1;
 	if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
 		retval = -EIO;
 		dev_err(&interface->dev, "Could not submitting URB\n");
@@ -280,7 +281,6 @@ static int yurex_probe(struct usb_interface *interface, const struct usb_device_
 
 	/* save our data pointer in this interface device */
 	usb_set_intfdata(interface, dev);
-	dev->bbu = -1;
 
 	/* we can register the device now, as it is ready */
 	retval = usb_register_dev(interface, &yurex_class);