From patchwork Wed Jan 21 15:55:21 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thierry Reding X-Patchwork-Id: 431527 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 8EAC01402A1 for ; Thu, 22 Jan 2015 02:55:58 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754157AbbAUPzz (ORCPT ); Wed, 21 Jan 2015 10:55:55 -0500 Received: from hqemgate16.nvidia.com ([216.228.121.65]:3954 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754374AbbAUPzj (ORCPT ); Wed, 21 Jan 2015 10:55:39 -0500 Received: from hqnvupgp07.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com id ; Wed, 21 Jan 2015 07:55:37 -0800 Received: from HQMAIL108.nvidia.com ([172.20.12.94]) by hqnvupgp07.nvidia.com (PGP Universal service); Wed, 21 Jan 2015 07:46:21 -0800 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Wed, 21 Jan 2015 07:46:21 -0800 Received: from UKMAIL101.nvidia.com (10.26.138.13) by HQMAIL108.nvidia.com (172.18.146.13) with Microsoft SMTP Server (TLS) id 15.0.847.32; Wed, 21 Jan 2015 15:55:39 +0000 Received: from localhost (10.2.68.160) by UKMAIL101.nvidia.com (10.26.138.13) with Microsoft SMTP Server (TLS) id 15.0.847.32; Wed, 21 Jan 2015 15:55:25 +0000 Date: Wed, 21 Jan 2015 16:55:21 +0100 From: Thierry Reding To: Tejun Heo CC: Paul Walmsley , , , , , , , , Subject: Re: next-20150120 broken on Tegra by "ata: libahci: Allow using multiple regulators" Message-ID: <20150121155519.GA25166@ulmo.nvidia.com> References: <20150121105001.GA9921@ulmo.nvidia.com> <20150121123134.GD8684@htj.dyndns.org> MIME-Version: 1.0 In-Reply-To: <20150121123134.GD8684@htj.dyndns.org> X-NVConfidentiality: public User-Agent: Mutt/1.5.23 (2014-03-12) X-Originating-IP: [10.2.68.160] X-ClientProxiedBy: UKMAIL102.nvidia.com (10.26.138.15) To UKMAIL101.nvidia.com (10.26.138.13) Content-Disposition: inline Sender: linux-tegra-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org On Wed, Jan 21, 2015 at 07:31:34AM -0500, Tejun Heo wrote: > On Wed, Jan 21, 2015 at 11:50:03AM +0100, Thierry Reding wrote: > > Tejun, preferably the attached patch should be squashed into commit > > c7d7ddee7e24 ("ata: libahci: Allow using multiple regulators") to avoid > > breaking bisectability. If you don't want to rewrite history, let me > > know and I can turn it into a proper patch. > > Yes, please make it a proper patch. > > Thanks a lot! Attaching the patch. Thierry From a4f78e3ec05f1b2ad86aa44d6bd5394d75a23a06 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Wed, 21 Jan 2015 11:50:52 +0100 Subject: [PATCH] ata: libahci: Fix devres cleanup on failure Commit c7d7ddee7e24 ("ata: libahci: Allow using multiple regulators") releases regulators during ahci_platform_put_resources(). That doesn't work because the function is run as part of the devres machinery. Such resources are torn down in reverse order. Since the array that holds pointers to the regulators is allocated using devres after the device context to which ahci_platform_put_resources() is attached, the memory will be freed before calling ahci_platform_put_resources() and thereby causing a use-after-free error. This commit fixes this by using regular allocations for the array. The memory can then be freed after the regulators have been released. This conserves the advantages of using the managed API. Reported-by: Paul Walmsley Signed-off-by: Thierry Reding --- drivers/ata/libahci_platform.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c index 73a086664ee7..504d534ccbfe 100644 --- a/drivers/ata/libahci_platform.c +++ b/drivers/ata/libahci_platform.c @@ -276,6 +276,7 @@ static void ahci_platform_put_resources(struct device *dev, void *res) if (hpriv->target_pwrs && hpriv->target_pwrs[c]) regulator_put(hpriv->target_pwrs[c]); + kfree(hpriv->target_pwrs); } static int ahci_platform_get_phy(struct ahci_host_priv *hpriv, u32 port, @@ -412,7 +413,7 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev) goto err_out; } sz = hpriv->nports * sizeof(*hpriv->target_pwrs); - hpriv->target_pwrs = devm_kzalloc(dev, sz, GFP_KERNEL); + hpriv->target_pwrs = kzalloc(sz, GFP_KERNEL); if (!hpriv->target_pwrs) { rc = -ENOMEM; goto err_out; -- 2.1.3