usb: core: fix information leak to userland

Structure usbdevfs_connectinfo is copied to userland with padding byted
after "slow" field uninitialized. It leads to leaking of contents of
kernel stack memory.

Signed-off-by: Vasiliy Kulikov <[e-mail]>
Cc: stable <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/core/devio.c

···
 
 static int proc_connectinfo(struct dev_state *ps, void __user *arg)
 {
-	struct usbdevfs_connectinfo ci;
+	struct usbdevfs_connectinfo ci = {
+		.devnum = ps->dev->devnum,
+		.slow = ps->dev->speed == USB_SPEED_LOW
+	};
 
-	ci.devnum = ps->dev->devnum;
-	ci.slow = ps->dev->speed == USB_SPEED_LOW;
 	if (copy_to_user(arg, &ci, sizeof(ci)))
 		return -EFAULT;
 	return 0;