From patchwork Wed Mar 1 08:47:39 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Reshetova, Elena" X-Patchwork-Id: 9597809 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 8128360414 for ; Wed, 1 Mar 2017 08:51:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7A5B726E98 for ; Wed, 1 Mar 2017 08:51:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6F1802841E; Wed, 1 Mar 2017 08:51:27 +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=-6.4 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM 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 155F5284F8 for ; Wed, 1 Mar 2017 08:51:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750738AbdCAIv0 (ORCPT ); Wed, 1 Mar 2017 03:51:26 -0500 Received: from mga09.intel.com ([134.134.136.24]:45913 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750736AbdCAIvZ (ORCPT ); Wed, 1 Mar 2017 03:51:25 -0500 Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 01 Mar 2017 00:48:00 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,224,1484035200"; d="scan'208";a="1103499062" Received: from elena-thinkpad-x230.fi.intel.com ([10.237.72.69]) by orsmga001.jf.intel.com with ESMTP; 01 Mar 2017 00:47:57 -0800 From: Elena Reshetova To: linux-kernel@vger.kernel.org Cc: linux-xfs@vger.kernel.org, peterz@infradead.org, gregkh@linuxfoundation.org, darrick.wong@oracle.com, david@fromorbit.com, Elena Reshetova , Hans Liljestrand , Kees Cook , David Windsor Subject: [PATCH 4/5] fs, xfs: convert xfs_cui_log_item.cui_refcount from atomic_t to refcount_t Date: Wed, 1 Mar 2017 10:47:39 +0200 Message-Id: <1488358060-693-5-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1488358060-693-1-git-send-email-elena.reshetova@intel.com> References: <1488358060-693-1-git-send-email-elena.reshetova@intel.com> Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@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 --- fs/xfs/xfs_refcount_item.c | 4 ++-- fs/xfs/xfs_refcount_item.h | 4 +++- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/xfs/xfs_refcount_item.c b/fs/xfs/xfs_refcount_item.c index 6e4c744..61bc570 100644 --- a/fs/xfs/xfs_refcount_item.c +++ b/fs/xfs/xfs_refcount_item.c @@ -205,7 +205,7 @@ xfs_cui_init( cuip->cui_format.cui_nextents = nextents; cuip->cui_format.cui_id = (uintptr_t)(void *)cuip; atomic_set(&cuip->cui_next_extent, 0); - atomic_set(&cuip->cui_refcount, 2); + refcount_set(&cuip->cui_refcount, 2); return cuip; } @@ -221,7 +221,7 @@ void xfs_cui_release( struct xfs_cui_log_item *cuip) { - if (atomic_dec_and_test(&cuip->cui_refcount)) { + if (refcount_dec_and_test(&cuip->cui_refcount)) { xfs_trans_ail_remove(&cuip->cui_item, SHUTDOWN_LOG_IO_ERROR); xfs_cui_item_free(cuip); } diff --git a/fs/xfs/xfs_refcount_item.h b/fs/xfs/xfs_refcount_item.h index 5b74ddd..7f23ff8 100644 --- a/fs/xfs/xfs_refcount_item.h +++ b/fs/xfs/xfs_refcount_item.h @@ -20,6 +20,8 @@ #ifndef __XFS_REFCOUNT_ITEM_H__ #define __XFS_REFCOUNT_ITEM_H__ +#include + /* * There are (currently) two pairs of refcount btree redo item types: * increase and decrease. The log items for these are CUI (refcount @@ -63,7 +65,7 @@ struct kmem_zone; */ struct xfs_cui_log_item { struct xfs_log_item cui_item; - atomic_t cui_refcount; + refcount_t cui_refcount; atomic_t cui_next_extent; unsigned long cui_flags; /* misc flags */ struct xfs_cui_log_format cui_format;