From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id 9A9297F52 for ; Mon, 2 Sep 2013 05:50:27 -0500 (CDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay1.corp.sgi.com (Postfix) with ESMTP id 85F1C8F8049 for ; Mon, 2 Sep 2013 03:50:27 -0700 (PDT) Received: from ipmail05.adl6.internode.on.net (ipmail05.adl6.internode.on.net [150.101.137.143]) by cuda.sgi.com with ESMTP id SPmEjitjThvG4Xs3 for ; Mon, 02 Sep 2013 03:50:25 -0700 (PDT) Received: from disappointment.disaster.area ([192.168.1.110] helo=disappointment) by dastard with esmtp (Exim 4.76) (envelope-from ) id 1VGRi9-0000sT-1Q for xfs@oss.sgi.com; Mon, 02 Sep 2013 20:50:21 +1000 Received: from dave by disappointment with local (Exim 4.80) (envelope-from ) id 1VGRi9-00089P-09 for xfs@oss.sgi.com; Mon, 02 Sep 2013 20:50:21 +1000 From: Dave Chinner Subject: [PATCH] xfs: check magic numbers in dir3 leaf verifier first Date: Mon, 2 Sep 2013 20:50:20 +1000 Message-Id: <1378119020-31299-1-git-send-email-david@fromorbit.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 Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com From: Dave Chinner Calling xfs_dir3_leaf_hdr_from_disk() in a verifier before validating the magic numbers in the buffer results in ASSERT failures due to mismatching magic numbers when a corruption occurs. Seeing as the verifier is supposed to catch the corruption and pass it back to the caller, having the verifier assert fail on error defeats the purpose of detecting the errors in the first place. Check the magic numbers direct from the buffer before decoding the header. Signed-off-by: Dave Chinner --- fs/xfs/xfs_dir2_leaf.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/fs/xfs/xfs_dir2_leaf.c b/fs/xfs/xfs_dir2_leaf.c index 08984ee..fa46d4b 100644 --- a/fs/xfs/xfs_dir2_leaf.c +++ b/fs/xfs/xfs_dir2_leaf.c @@ -165,6 +165,7 @@ xfs_dir3_leaf_check_int( (char *)&ents[hdr->count] > (char *)xfs_dir2_leaf_bests_p(ltp)) return false; + /* Check hash value order, count stale entries. */ for (i = stale = 0; i < hdr->count; i++) { if (i + 1 < hdr->count) { @@ -180,6 +181,11 @@ xfs_dir3_leaf_check_int( return true; } +/* + * We verify the magic numbers before decoding the leaf header so that on debug + * kernels we don't get assertion failures in xfs_dir3_leaf_hdr_from_disk() due + * to incorrect magic numbers. + */ static bool xfs_dir3_leaf_verify( struct xfs_buf *bp, @@ -191,24 +197,25 @@ xfs_dir3_leaf_verify( ASSERT(magic == XFS_DIR2_LEAF1_MAGIC || magic == XFS_DIR2_LEAFN_MAGIC); - xfs_dir3_leaf_hdr_from_disk(&leafhdr, leaf); if (xfs_sb_version_hascrc(&mp->m_sb)) { struct xfs_dir3_leaf_hdr *leaf3 = bp->b_addr; + __uint16_t magic3; - if ((magic == XFS_DIR2_LEAF1_MAGIC && - leafhdr.magic != XFS_DIR3_LEAF1_MAGIC) || - (magic == XFS_DIR2_LEAFN_MAGIC && - leafhdr.magic != XFS_DIR3_LEAFN_MAGIC)) - return false; + magic3 = (magic == XFS_DIR2_LEAF1_MAGIC) ? XFS_DIR3_LEAF1_MAGIC + : XFS_DIR3_LEAFN_MAGIC; + if (leaf3->info.hdr.magic != cpu_to_be16(magic3)) + return false; if (!uuid_equal(&leaf3->info.uuid, &mp->m_sb.sb_uuid)) return false; if (be64_to_cpu(leaf3->info.blkno) != bp->b_bn) return false; } else { - if (leafhdr.magic != magic) + if (leaf->hdr.info.magic != cpu_to_be32(magic)) return false; } + + xfs_dir3_leaf_hdr_from_disk(&leafhdr, leaf); return xfs_dir3_leaf_check_int(mp, &leafhdr, leaf); } -- 1.8.3.2 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs