Re: [PATCH v4 5/6] rfcomm: Fix the reference counting of tty_port

[Gianluca Anzolin <gianluca@sottospazio.it>]

On Fri, Jul 26, 2013 at 08:20:47PM -0400, Peter Hurley wrote:
> On 07/26/2013 01:18 PM, Gianluca Anzolin wrote:
> >@@ -614,7 +601,9 @@ static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
> >  					return;
> >  				}
> >
> >-				rfcomm_dev_del(dev);
> >+				set_bit(RFCOMM_TTY_RELEASED, &dev->flags);
> >+				tty_port_put(&dev->port);
> 
> Since this code can execute concurrently with rfcomm_release_dev(),
> and the 'initial' port reference must only be dropped once, this should be
> 
> 				if (!test_and_set_bit(RFCOMM_TTY_RELEASED, &dev->flags)
> 					tty_port_put(&dev->port);
> 
> Regards,
> Peter Hurley

I somehow convinced myself that it was safe but clearly it wasn't. Should I
also change the same way the code in rfcomm_tty_hangup()?

Thanks,

Gianluca