In the Linux kernel, the following vulnerability has been resolved: serial: 8250: Fix oops for port->pm on uartchangepm() Unloading a hardware specific 8250 driver can produce error "Unable to handle kernel paging request at virtual address" about ten seconds after unloading the driver. This happens on uarthangup() calling uartchangepm(). Turns out commit 04e82793f068 ("serial: 8250: Reinit port->pm on port specific driver unbind") was only a partial fix. If the hardware specific driver has initialized port->pm function, we need to clear port->pm too. Just reinitializing port->ops does not do this. Otherwise serial8250pm() will call port->pm() instead of serial8250dopm().