From patchwork Mon Mar 28 17:08:09 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shuah Khan X-Patchwork-Id: 8679951 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 75CF0C0553 for ; Mon, 28 Mar 2016 17:08:16 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 941C420225 for ; Mon, 28 Mar 2016 17:08:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 35C33201EC for ; Mon, 28 Mar 2016 17:08:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754020AbcC1RIM (ORCPT ); Mon, 28 Mar 2016 13:08:12 -0400 Received: from lists.s-osg.org ([54.187.51.154]:58537 "EHLO lists.s-osg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753149AbcC1RIM (ORCPT ); Mon, 28 Mar 2016 13:08:12 -0400 Received: from [192.168.1.40] (c-73-181-52-62.hsd1.co.comcast.net [73.181.52.62]) by lists.s-osg.org (Postfix) with ESMTPSA id D2B7F462A0; Mon, 28 Mar 2016 10:08:10 -0700 (PDT) To: Mauro Carvalho Chehab , Javier Martinez Canillas Cc: Shuah Khan , Linux Media Mailing List From: Shuah Khan Subject: au0828_v4l2_device_register() Message-ID: <56F964F9.8080703@osg.samsung.com> Date: Mon, 28 Mar 2016 11:08:09 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Spam-Status: No, score=-7.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Hi Mauro/Javier, I can't figure out when au0828_v4l2_device_register() was added. Must be in Linux 4.5 as I can't find this change in Linux 4.4 This used to be a call to v4l2_device_register() from au0828_usb_probe(). When the code was moved, locking bugs are introduced. Notice that au0828_v4l2_device_register() does the following in error legs: mutex_unlock(&dev->lock); kfree(dev); And au0828_usb_probe() also does the same cleanup when au0828_v4l2_device_register() returns error: retval = au0828_v4l2_device_register(interface, dev); if (retval) { au0828_usb_v4l2_media_release(dev); mutex_unlock(&dev->lock); kfree(dev); return retval; } We could be seeing some problems if this fails. Please let me know if you would like a patch to fix this. The following is the right fix: thanks, -- Shuah diff --git a/drivers/media/usb/au0828/au0828-video.c b/drivers/media/usb/au0828/au0828-video.c index 32d7db9..7d0ec4c 100644 --- a/drivers/media/usb/au0828/au0828-video.c +++ b/drivers/media/usb/au0828/au0828-video.c @@ -679,8 +679,6 @@ int au0828_v4l2_device_register(struct usb_interface *interface, if (retval) { pr_err("%s() v4l2_device_register failed\n", __func__); - mutex_unlock(&dev->lock); - kfree(dev); return retval; } @@ -691,8 +689,6 @@ int au0828_v4l2_device_register(struct usb_interface *interface, if (retval) { pr_err("%s() v4l2_ctrl_handler_init failed\n", __func__); - mutex_unlock(&dev->lock); - kfree(dev); return retval; } dev->v4l2_dev.ctrl_handler = &dev->v4l2_ctrl_hdl;