Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754117AbaAFLAj (ORCPT ); Mon, 6 Jan 2014 06:00:39 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:42192 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752776AbaAFLAf (ORCPT ); Mon, 6 Jan 2014 06:00:35 -0500 X-IronPort-AV: E=Sophos;i="4.95,612,1384300800"; d="scan'208";a="87838192" Message-ID: <52CA8CD1.6080003@citrix.com> Date: Mon, 6 Jan 2014 11:00:33 +0000 From: David Vrabel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.16) Gecko/20121215 Iceowl/1.0b1 Icedove/3.0.11 MIME-Version: 1.0 To: Ian Campbell CC: Levente Kurusa , Stefano Stabellini , Greg Kroah-Hartman , LKML , , Andrew Morton , Boris Ostrovsky Subject: Re: [Xen-devel] [PATCH 26/38] xen: xenbus: add missing put_device call References: <1387465429-3568-2-git-send-email-levex@linux.com> <1387465429-3568-27-git-send-email-levex@linux.com> <52C56F43.6030804@citrix.com> <1389002445.13274.23.camel@kazak.uk.xensource.com> In-Reply-To: <1389002445.13274.23.camel@kazak.uk.xensource.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.80.2.76] X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/01/14 10:00, Ian Campbell wrote: > On Thu, 2014-01-02 at 13:53 +0000, David Vrabel wrote: >> On 19/12/13 15:03, Levente Kurusa wrote: >>> This is required so that we give up the last reference to the device. >>> >>> Signed-off-by: Levente Kurusa >>> --- >>> drivers/xen/xenbus/xenbus_probe.c | 4 +++- >>> 1 file changed, 3 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c >>> index 3c0a74b..4abb9ee 100644 >>> --- a/drivers/xen/xenbus/xenbus_probe.c >>> +++ b/drivers/xen/xenbus/xenbus_probe.c >>> @@ -465,8 +465,10 @@ int xenbus_probe_node(struct xen_bus_type *bus, >>> >>> /* Register with generic device framework. */ >>> err = device_register(&xendev->dev); >>> - if (err) >>> + if (err) { >>> + put_device(&xendev->dev); >>> goto fail; >>> + } >>> >>> return 0; >>> fail: >> >> There is a kfree(xendev) here so this introduces a double-free. > > How? put_device doesn't touch xendev itself, does it? It just drops the > ref on the dev member which is not separately dynamically allocated and > so not freed either. Releasing all references to the struct device frees the containing structure via xenbus->dev.release. i.e., xenbus_dev_release() which does kfree(xendev). David -- 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/