From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com ([134.134.136.24]:51230 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751075AbdCAJEF (ORCPT ); Wed, 1 Mar 2017 04:04:05 -0500 From: Elena Reshetova Subject: [PATCH 1/5] fs, xfs: convert xfs_bui_log_item.bui_refcount from atomic_t to refcount_t Date: Wed, 1 Mar 2017 10:47:36 +0200 Message-Id: <1488358060-693-2-git-send-email-elena.reshetova@intel.com> 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 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, david@fromorbit.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_bmap_item.c | 4 ++-- fs/xfs/xfs_bmap_item.h | 4 +++- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/xfs/xfs_bmap_item.c b/fs/xfs/xfs_bmap_item.c index 9bf57c7..33104ad 100644 --- a/fs/xfs/xfs_bmap_item.c +++ b/fs/xfs/xfs_bmap_item.c @@ -199,7 +199,7 @@ xfs_bui_init( buip->bui_format.bui_nextents = XFS_BUI_MAX_FAST_EXTENTS; buip->bui_format.bui_id = (uintptr_t)(void *)buip; atomic_set(&buip->bui_next_extent, 0); - atomic_set(&buip->bui_refcount, 2); + refcount_set(&buip->bui_refcount, 2); return buip; } @@ -215,7 +215,7 @@ void xfs_bui_release( struct xfs_bui_log_item *buip) { - if (atomic_dec_and_test(&buip->bui_refcount)) { + if (refcount_dec_and_test(&buip->bui_refcount)) { xfs_trans_ail_remove(&buip->bui_item, SHUTDOWN_LOG_IO_ERROR); xfs_bui_item_free(buip); } diff --git a/fs/xfs/xfs_bmap_item.h b/fs/xfs/xfs_bmap_item.h index c867daa..988a6ae 100644 --- a/fs/xfs/xfs_bmap_item.h +++ b/fs/xfs/xfs_bmap_item.h @@ -20,6 +20,8 @@ #ifndef __XFS_BMAP_ITEM_H__ #define __XFS_BMAP_ITEM_H__ +#include + /* * There are (currently) two pairs of bmap btree redo item types: map & unmap. * The common abbreviations for these are BUI (bmap update intent) and BUD @@ -61,7 +63,7 @@ struct kmem_zone; */ struct xfs_bui_log_item { struct xfs_log_item bui_item; - atomic_t bui_refcount; + refcount_t bui_refcount; atomic_t bui_next_extent; unsigned long bui_flags; /* misc flags */ struct xfs_bui_log_format bui_format; -- 2.7.4