releases/4.2.1/libxfs-readahead-of-dir3-data-blocks-should-use-the-read-verifier.patch

From 2f123bce18943fff819bc10f8868ffb9149fc622 Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <darrick.wong@oracle.com>
Date: Wed, 19 Aug 2015 10:33:58 +1000
Subject: libxfs: readahead of dir3 data blocks should use the read verifier

From: "Darrick J. Wong" <darrick.wong@oracle.com>

commit 2f123bce18943fff819bc10f8868ffb9149fc622 upstream.

In the dir3 data block readahead function, use the regular read
verifier to check the block's CRC and spot-check the block contents
instead of directly calling only the spot-checking routine.  This
prevents corrupted directory data blocks from being read into the
kernel, which can lead to garbage ls output and directory loops (if
say one of the entries contains slashes and other junk).

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/xfs/libxfs/xfs_dir2_data.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/xfs/libxfs/xfs_dir2_data.c
+++ b/fs/xfs/libxfs/xfs_dir2_data.c
@@ -252,7 +252,8 @@ xfs_dir3_data_reada_verify(
 		return;
 	case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
 	case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
-		xfs_dir3_data_verify(bp);
+		bp->b_ops = &xfs_dir3_data_buf_ops;
+		bp->b_ops->verify_read(bp);
 		return;
 	default:
 		xfs_buf_ioerror(bp, -EFSCORRUPTED);