In the Linux kernel, the following vulnerability has been resolved:

hwmon: (powerz) Fix use-after-free on USB disconnect

After powerz_disconnect() frees the URB and releases the mutex, a
subsequent powerz_read() call can acquire the mutex and call
powerz_read_data(), which dereferences the freed URB pointer.

Fix by:
 - Setting priv->urb to NULL in powerz_disconnect() so that
   powerz_read_data() can detect the disconnected state.
 - Adding a !priv->urb check at the start of powerz_read_data()
   to return -ENODEV on a disconnected device.
 - Moving usb_set_intfdata() before hwmon registration so the
   disconnect handler can always find the priv pointer.