From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753652AbdCHOeU (ORCPT ); Wed, 8 Mar 2017 09:34:20 -0500 Received: from mga09.intel.com ([134.134.136.24]:34911 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753425AbdCHOeR (ORCPT ); Wed, 8 Mar 2017 09:34:17 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,262,1486454400"; d="scan'208";a="1139427383" From: Elena Reshetova To: darrick.wong@oracle.com Cc: linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, 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, 8 Mar 2017 10:53:38 +0200 Message-Id: <1488963219-11709-5-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1488963219-11709-1-git-send-email-elena.reshetova@intel.com> References: <1488963219-11709-1-git-send-email-elena.reshetova@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 | 2 +- 2 files changed, 3 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..abc0377 100644 --- a/fs/xfs/xfs_refcount_item.h +++ b/fs/xfs/xfs_refcount_item.h @@ -63,7 +63,7 @@ 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; -- 2.7.4