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Date: Tue, 18 Jul 2017 20:22:59 +0100
From: Okash Khawaja <okash.khawaja@gmail.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>,
        "devel@driverdev.osuosl.org" <devel@driverdev.osuosl.org>,
        Kirk Reiser <kirk@reisers.ca>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
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        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Jiri Slaby <jslaby@suse.com>,
        Samuel Thibault <samuel.thibault@ens-lyon.org>,
        Chris Brannon <chris@the-brannons.com>
Subject: Re: [patch 0/3] Re: tty contention resulting from tty_open_by_device
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Message-ID: <20170718192259.GA2799@sanghar>
References: <20170709114153.157783481@gmail.com>
 <20170710125233.2006733e@alans-desktop>
 <20170710123307.GA777@sanghar>
 <20170712192028.70bc0d54@alans-desktop>
 <20170713112954.GA665@sanghar>
 <20170717123145.GE24503@kroah.com>
 <3E107A3D-D8E2-43E5-8DCB-F9DE2F5AAAEA@gmail.com>
 <20170717230438.5c3bd397@alans-desktop>
 <20170718112952.GA564@sanghar>
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On Tue, Jul 18, 2017 at 03:26:37PM +0300, Dan Carpenter wrote:
> > +       if (tty) {
> > +               /* drop kref from tty_driver_lookup_tty() */
> > +               tty_kref_put(tty);
> > +               tty = ERR_PTR(-EBUSY);
> > +       } else { /* tty_init_dev returns tty with the tty_lock held */
> > +               tty = tty_init_dev(driver, index);
> > +               tty_port_set_kopened(tty->port, 1);
>                                        ^^^^^^^^^
> 
> tty_init_dev() can fail leading to an error pointer dereference here.

Thanks very much. I will check for error pointer here.

Okash