Re: [PATCH 3/3] xfs: sb_spino_align is not verified

["Darrick J. Wong" <djwong@kernel.org>]

On Thu, Oct 24, 2024 at 01:51:05PM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
> 
> It's just read in from the superblock and used without doing any
> validity checks at all on the value.
> 
> Fixes: fb4f2b4e5a82 ("xfs: add sparse inode chunk alignment superblock field")
> Signed-off-by: Dave Chinner <dchinner@redhat.com>

Cc: <stable@vger.kernel.org> # v4.2

Oof yeah that's quite a gap!
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/xfs/libxfs/xfs_sb.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
> index d95409f3cba6..0d181bc140f0 100644
> --- a/fs/xfs/libxfs/xfs_sb.c
> +++ b/fs/xfs/libxfs/xfs_sb.c
> @@ -398,6 +398,20 @@ xfs_validate_sb_common(
>  					 sbp->sb_inoalignmt, align);
>  				return -EINVAL;
>  			}
> +
> +			if (!sbp->sb_spino_align ||
> +			    sbp->sb_spino_align > sbp->sb_inoalignmt ||
> +			    (sbp->sb_inoalignmt % sbp->sb_spino_align) != 0) {
> +				xfs_warn(mp,
> +				"Sparse inode alignment (%u) is invalid.",
> +					sbp->sb_spino_align);
> +				return -EINVAL;
> +			}
> +		} else if (sbp->sb_spino_align) {
> +			xfs_warn(mp,
> +				"Sparse inode alignment (%u) should be zero.",
> +				sbp->sb_spino_align);
> +			return -EINVAL;
>  		}
>  	} else if (sbp->sb_qflags & (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD |
>  				XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD)) {
> -- 
> 2.45.2
> 
>