commit 5610bcfe8693c02e2e4c8b31427f1bdbdecc839c upstream. A race condition may occur if the user physically removes the USB device while calling open() for this device node. This is a race condition between the ufx_ops_open() function and the ufx_usb_disconnect() function, which may eventually result in UAF. So, add a mutex to the ufx_ops_open() and ufx_usb_disconnect() functions to avoid race contidion of krefs. Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>