Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754233Ab2JJJ5b (ORCPT ); Wed, 10 Oct 2012 05:57:31 -0400 Received: from cantor2.suse.de ([195.135.220.15]:57098 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751570Ab2JJJ5a (ORCPT ); Wed, 10 Oct 2012 05:57:30 -0400 From: Oliver Neukum To: Constantine Shulyupin Cc: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] USB: usb-skeleton.c: fix compilation error and restore kref_put on fail in skel_open Date: Wed, 10 Oct 2012 11:55:45 +0200 Message-ID: <1397300.1BYdlnI91r@linux-lqwf.site> Organization: SUSE User-Agent: KMail/4.8.4 (Linux/3.6.0-rc4-12-desktop+; KDE/4.9.1; x86_64; ; ) In-Reply-To: <1349603832-26424-1-git-send-email-const@MakeLinux.com> References: <1349603832-26424-1-git-send-email-const@MakeLinux.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1510 Lines: 45 On Sunday 07 October 2012 11:57:12 Constantine Shulyupin wrote: > From: Constantine Shulyupin > > Function skel_open increments usage count for the device with kref_get and the usage count should be decremented on the function failure. > > Some last changes in function skel_open and finally commit > 52a7499 Revert "USB: usb-skeleton.c: fix open/disconnect race" > introduced a bug in function skel_open, which this patch fixes. > > Signed-off-by: Constantine Shulyupin > --- > drivers/usb/usb-skeleton.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c > index 0616f23..027005b 100644 > --- a/drivers/usb/usb-skeleton.c > +++ b/drivers/usb/usb-skeleton.c > @@ -113,8 +113,10 @@ static int skel_open(struct inode *inode, struct file *file) > mutex_lock(&dev->io_mutex); > > retval = usb_autopm_get_interface(interface); > - if (retval) > - goto out_err; > + if (retval) { > + kref_put(&dev->kref, skel_delete); > + goto exit; > + } > > /* save our object in the file's private structure */ > file->private_data = dev; Hi, good catch, but the fix is wrong. You also need to drop the lock. Regards Oliver -- 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/