From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Resent-Message-ID: <20170227145016.yb3csncdleqizwtf@eorzea.usersys.redhat.com> Resent-To: sandeen@sandeen.net Received: from mga02.intel.com ([134.134.136.20]:55037 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752752AbdBUPtj (ORCPT ); Tue, 21 Feb 2017 10:49:39 -0500 From: Elena Reshetova Subject: [PATCH 6/7] fs, xfs: convert xfs_cui_log_item.cui_refcount from atomic_t to refcount_t Date: Tue, 21 Feb 2017 17:49:06 +0200 Message-Id: <1487692147-17066-7-git-send-email-elena.reshetova@intel.com> In-Reply-To: <1487692147-17066-1-git-send-email-elena.reshetova@intel.com> References: <1487692147-17066-1-git-send-email-elena.reshetova@intel.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: linux-kernel@vger.kernel.org Cc: linux-xfs@vger.kernel.org, peterz@infradead.org, gregkh@linuxfoundation.org, darrick.wong@oracle.com, Elena Reshetova , Hans Liljestrand , Kees Cook , David Windsor 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; -- 2.7.4