From patchwork Mon Mar 6 14:21:14 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Reshetova, Elena" X-Patchwork-Id: 9606709 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 9C48F6046A for ; Mon, 6 Mar 2017 14:35:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9019126224 for ; Mon, 6 Mar 2017 14:35:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8461628305; Mon, 6 Mar 2017 14:35:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F21F826224 for ; Mon, 6 Mar 2017 14:35:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932415AbdCFOfX (ORCPT ); Mon, 6 Mar 2017 09:35:23 -0500 Received: from mga05.intel.com ([192.55.52.43]:51158 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753184AbdCFOY4 (ORCPT ); Mon, 6 Mar 2017 09:24:56 -0500 Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP; 06 Mar 2017 06:24:14 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,254,1484035200"; d="scan'208";a="72746576" Received: from rzetikx-mobl.ger.corp.intel.com (HELO elena-ThinkPad-X230.ger.corp.intel.com) ([10.249.41.1]) by fmsmga005.fm.intel.com with ESMTP; 06 Mar 2017 06:24:08 -0800 From: Elena Reshetova To: gregkh@linuxfoundation.org Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, netdev@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-bcache@vger.kernel.org, linux-raid@vger.kernel.org, linux-media@vger.kernel.org, devel@linuxdriverproject.org, linux-pci@vger.kernel.org, linux-s390@vger.kernel.org, fcoe-devel@open-fcoe.org, linux-scsi@vger.kernel.org, open-iscsi@googlegroups.com, devel@driverdev.osuosl.org, target-devel@vger.kernel.org, linux-serial@vger.kernel.org, linux-usb@vger.kernel.org, peterz@infradead.org, Elena Reshetova , Hans Liljestrand , Kees Cook , David Windsor Subject: [PATCH 27/29] drivers, usb: convert ep_data.count from atomic_t to refcount_t Date: Mon, 6 Mar 2017 16:21:14 +0200 Message-Id: <1488810076-3754-28-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1488810076-3754-1-git-send-email-elena.reshetova@intel.com> References: <1488810076-3754-1-git-send-email-elena.reshetova@intel.com> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor --- drivers/usb/gadget/legacy/inode.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c index 81d76f3..d21a5f8 100644 --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -191,7 +191,7 @@ enum ep_state { struct ep_data { struct mutex lock; enum ep_state state; - atomic_t count; + refcount_t count; struct dev_data *dev; /* must hold dev->lock before accessing ep or req */ struct usb_ep *ep; @@ -206,12 +206,12 @@ struct ep_data { static inline void get_ep (struct ep_data *data) { - atomic_inc (&data->count); + refcount_inc (&data->count); } static void put_ep (struct ep_data *data) { - if (likely (!atomic_dec_and_test (&data->count))) + if (likely (!refcount_dec_and_test (&data->count))) return; put_dev (data->dev); /* needs no more cleanup */ @@ -1562,7 +1562,7 @@ static int activate_ep_files (struct dev_data *dev) init_waitqueue_head (&data->wait); strncpy (data->name, ep->name, sizeof (data->name) - 1); - atomic_set (&data->count, 1); + refcount_set (&data->count, 1); data->dev = dev; get_dev (dev);