Return-path: Received: from mail-bk0-f46.google.com ([209.85.214.46]:50955 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756586Ab3JJSRR (ORCPT ); Thu, 10 Oct 2013 14:17:17 -0400 From: Christian Lamparter To: "John W. Linville" Cc: Alexey Khoroshilov , Fabio Estevam , linux-wireless@vger.kernel.org, "netdev@vger.kernel.org" , linux-kernel , ldv-project@linuxtesting.org Subject: Re: [PATCH] carl9170: fix leaks at failure path in carl9170_usb_probe() Date: Thu, 10 Oct 2013 20:17:09 +0200 Message-ID: <9668029.9aMApUIsT2@blech> (sfid-20131010_201755_644323_4EF8F17B) In-Reply-To: <20131010175952.GG2691@tuxdriver.com> References: <1380340311-4630-1-git-send-email-khoroshilov@ispras.ru> <52466624.4040106@ispras.ru> <20131010175952.GG2691@tuxdriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thursday, October 10, 2013 01:59:52 PM John W. Linville wrote: > On Sat, Sep 28, 2013 at 01:16:20AM -0400, Alexey Khoroshilov wrote: > > On 28.09.2013 00:17, Fabio Estevam wrote: > > >On Sat, Sep 28, 2013 at 12:51 AM, Alexey Khoroshilov > > > wrote: > > > > > >>- return request_firmware_nowait(THIS_MODULE, 1, CARL9170FW_NAME, > > >>+ err = request_firmware_nowait(THIS_MODULE, 1, CARL9170FW_NAME, > > >> &ar->udev->dev, GFP_KERNEL, ar, carl9170_usb_firmware_step2); > > >>+ if (err) { > > >>+ usb_put_dev(udev); > > >>+ usb_put_dev(udev); > > >You are doing the same free twice. > > Yes, because it was get twice. > > >I guess you meant to also free: usb_put_dev(ar->udev) > > udev and ar->udev are equal, so technically the patch is correct. > > > > I agree that there is some inconsistency, but I would prefer to fix > > it at usb_get_dev() side with a comment about reasons for the double > > get. > > What is the reason for the double get? The idea is: One (extra) reference protects the asynchronous firmware loader callback from disappearing "udev". Regards, Chr