Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754884Ab3GYG0v (ORCPT ); Thu, 25 Jul 2013 02:26:51 -0400 Received: from mail-ea0-f173.google.com ([209.85.215.173]:40785 "EHLO mail-ea0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753032Ab3GYG0u (ORCPT ); Thu, 25 Jul 2013 02:26:50 -0400 Message-ID: <51F0C525.8080506@suse.cz> Date: Thu, 25 Jul 2013 08:26:45 +0200 From: Jiri Slaby User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:19.0) Gecko/20130124 Thunderbird/19.0 MIME-Version: 1.0 To: Gianluca Anzolin , gregkh@linuxfoundation.org CC: gustavo@padovan.org, peter@hurleysoftware.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tty_port: Fix refcounting leak in tty_port_tty_hangup() References: <1374729977-7164-1-git-send-email-gianluca@sottospazio.it> In-Reply-To: <1374729977-7164-1-git-send-email-gianluca@sottospazio.it> X-Enigmail-Version: 1.6a1pre Content-Type: text/plain; charset=ISO-8859-2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1671 Lines: 56 On 07/25/2013 07:26 AM, Gianluca Anzolin wrote: > The function tty_port_tty_hangup() could leak a reference to the tty_struct: > > struct tty_struct *tty = tty_port_tty_get(port); > > if (tty && (!check_clocal || !C_CLOCAL(tty))) { > tty_hangup(tty); > tty_kref_put(tty); > } > > If tty != NULL and the second condition is false we never call tty_kref_put and > the reference is leaked. > > Fix by always calling tty_kref_put() which accepts a NULL argument. > > The patch fixes a regression introduced by commit aa27a094. > > Acked-by: Gustavo Padovan > Signed-off-by: Gianluca Anzolin Acked-by: Jiri Slaby Thanks for the fix. > --- > drivers/tty/tty_port.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c > index 121aeb9..f597e88 100644 > --- a/drivers/tty/tty_port.c > +++ b/drivers/tty/tty_port.c > @@ -256,10 +256,9 @@ void tty_port_tty_hangup(struct tty_port *port, bool check_clocal) > { > struct tty_struct *tty = tty_port_tty_get(port); > > - if (tty && (!check_clocal || !C_CLOCAL(tty))) { > + if (tty && (!check_clocal || !C_CLOCAL(tty))) > tty_hangup(tty); > - tty_kref_put(tty); > - } > + tty_kref_put(tty); > } > EXPORT_SYMBOL_GPL(tty_port_tty_hangup); > > -- js suse labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/