From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p8L9ggiT130484 for ; Wed, 21 Sep 2011 04:42:42 -0500 Received: from mx1.redhat.com (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id A32511608D44 for ; Wed, 21 Sep 2011 02:48:03 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id VzEG5BvgCWpzxfuN for ; Wed, 21 Sep 2011 02:48:03 -0700 (PDT) From: Lukas Czerner Subject: [PATCH v3] xfs: fix possible overflow in xfs_ioc_trim() Date: Wed, 21 Sep 2011 11:42:30 +0200 Message-Id: <1316598150-12447-1-git-send-email-lczerner@redhat.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com Cc: hch@infradead.org, Lukas Czerner In xfs_ioc_trim it is possible that computing the last allocation group to discard might overflow for big start & len values, because the result might be bigger then xfs_agnumber_t which is 32 bit long. Fix this by not allowing the start and end block of the range to be beyond the end of the file system. Note that if the start is beyond the end of the file system we have to return -EINVAL, but in the "end" case we have to truncate it to the fs size. Also introduce "end" variable, rather than using start+len which which might be more confusing to get right as this bug shows. Signed-off-by: Lukas Czerner --- v2: Use sb_dblocks instead of XFS_MAX_DBLOCKS to get max block count v3: Rework the patch fs/xfs/xfs_discard.c | 20 ++++++++++---------- 1 files changed, 10 insertions(+), 10 deletions(-) diff --git a/fs/xfs/xfs_discard.c b/fs/xfs/xfs_discard.c index 244e797..8a24f0c 100644 --- a/fs/xfs/xfs_discard.c +++ b/fs/xfs/xfs_discard.c @@ -38,7 +38,7 @@ xfs_trim_extents( struct xfs_mount *mp, xfs_agnumber_t agno, xfs_fsblock_t start, - xfs_fsblock_t len, + xfs_fsblock_t end, xfs_fsblock_t minlen, __uint64_t *blocks_trimmed) { @@ -100,7 +100,7 @@ xfs_trim_extents( * down partially overlapping ranges for now. */ if (XFS_AGB_TO_FSB(mp, agno, fbno) + flen < start || - XFS_AGB_TO_FSB(mp, agno, fbno) >= start + len) { + XFS_AGB_TO_FSB(mp, agno, fbno) > end) { trace_xfs_discard_exclude(mp, agno, fbno, flen); goto next_extent; } @@ -145,7 +145,7 @@ xfs_ioc_trim( struct request_queue *q = mp->m_ddev_targp->bt_bdev->bd_disk->queue; unsigned int granularity = q->limits.discard_granularity; struct fstrim_range range; - xfs_fsblock_t start, len, minlen; + xfs_fsblock_t start, end, minlen; xfs_agnumber_t start_agno, end_agno, agno; __uint64_t blocks_trimmed = 0; int error, last_error = 0; @@ -165,19 +165,19 @@ xfs_ioc_trim( * matter as trimming blocks is an advisory interface. */ start = XFS_B_TO_FSBT(mp, range.start); - len = XFS_B_TO_FSBT(mp, range.len); + end = start + XFS_B_TO_FSBT(mp, range.len) - 1; minlen = XFS_B_TO_FSB(mp, max_t(u64, granularity, range.minlen)); - start_agno = XFS_FSB_TO_AGNO(mp, start); - if (start_agno >= mp->m_sb.sb_agcount) + if (start >= mp->m_sb.sb_dblocks) return -XFS_ERROR(EINVAL); + if (end > mp->m_sb.sb_dblocks - 1) + end = mp->m_sb.sb_dblocks - 1; - end_agno = XFS_FSB_TO_AGNO(mp, start + len); - if (end_agno >= mp->m_sb.sb_agcount) - end_agno = mp->m_sb.sb_agcount - 1; + start_agno = XFS_FSB_TO_AGNO(mp, start); + end_agno = XFS_FSB_TO_AGNO(mp, end); for (agno = start_agno; agno <= end_agno; agno++) { - error = -xfs_trim_extents(mp, agno, start, len, minlen, + error = -xfs_trim_extents(mp, agno, start, end, minlen, &blocks_trimmed); if (error) last_error = error; -- 1.7.4.4 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs