From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from verein.lst.de ([213.95.11.211]:43770 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934113AbdBQRBa (ORCPT ); Fri, 17 Feb 2017 12:01:30 -0500 Date: Fri, 17 Feb 2017 18:01:28 +0100 From: Christoph Hellwig To: Keith Busch Cc: Christoph Hellwig , scott.bauer@intel.com, jonathan.derrick@intel.com, axboe@fb.com, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org Subject: Re: [PATCH 4/4] nvme: re-check security protocol support after reset Message-ID: <20170217170128.GA29208@lst.de> References: <20170217125941.14319-1-hch@lst.de> <20170217125941.14319-5-hch@lst.de> <20170217152651.GA18275@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20170217152651.GA18275@localhost.localdomain> Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org On Fri, Feb 17, 2017 at 10:26:51AM -0500, Keith Busch wrote: > On Fri, Feb 17, 2017 at 01:59:41PM +0100, Christoph Hellwig wrote: > > @@ -1789,7 +1789,8 @@ static void nvme_reset_work(struct work_struct *work) > > if (result) > > goto out; > > > > - if ((dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) && !dev->ctrl.opal_dev) { > > + kfree(dev->ctrl.opal_dev); > > + if (dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) { > > dev->ctrl.opal_dev = > > init_opal_dev(&dev->ctrl, &nvme_sec_submit); > > } > > A couple things. > > This has a use-after-free in opal_unlock_from_suspend if the nvme > device had an opal_dev before, but no longer support the capability > after resume. So you'd want to set ctrl.opal_dev to NULL after the free. > > But we don't want to unconditionally free it anyway during resume > since opal_unlock_from_suspend requires the exisiting opal_dev state > information saved in the 'unlk_list'. > > Something like this instead: Yes, that looks fine to me. We'll probably also need the additional fixup Scott pointed out.