xfs: verify dirblocklog correctly

commit 83d230eb5c638949350f4761acdfc0af5cb1bc00 upstream.

sb_dirblklog is added to sb_blocklog to compute the directory block size
in bytes.  Therefore, we must compare the sum of both those values
against XFS_MAX_BLOCKSIZE_LOG, not just dirblklog.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index 2580262e4ea00c3dc728b041dca125f4f7078373..584ec896a53374f81da05906d517fba717686504 100644 (file)
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -242,7 +242,7 @@ xfs_mount_validate_sb(
            sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG                    ||
            sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG                    ||
            sbp->sb_blocksize != (1 << sbp->sb_blocklog)                ||
-           sbp->sb_dirblklog > XFS_MAX_BLOCKSIZE_LOG                   ||
+           sbp->sb_dirblklog + sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG ||
            sbp->sb_inodesize < XFS_DINODE_MIN_SIZE                     ||
            sbp->sb_inodesize > XFS_DINODE_MAX_SIZE                     ||
            sbp->sb_inodelog < XFS_DINODE_MIN_LOG                       ||