On 01/28/2014 11:28 PM, Eric Sandeen wrote:
> xfs_mount_validate_sb doesn't check sb_inopblock for sanity
> (as does its xfs_repair counterpart, FWIW).
>
> If it's out of bounds, we can go off the rails in i.e.
> xfs_inode_buf_verify(), which uses sb_inopblock as a loop
> limit when stepping through a metadata buffer.
>
> The problem can be demonstrated easily by corrupting
> sb_inopblock with xfs_db and trying to mount the result:
>
> # mkfs.xfs -dfile,name=fsfile,size=1g
> # xfs_db -x fsfile
> xfs_db> sb 0
> xfs_db> write inopblock 512
> inopblock = 512
> xfs_db> quit
>
> # mount -o loop fsfile mnt
> and we blow up in xfs_inode_buf_verify().
>
> With this patch, we get a (very noisy) corruption error,
> and fail the mount as we should.
>
> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
> ---
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
>
> diff --git a/fs/xfs/xfs_sb.c b/fs/xfs/xfs_sb.c
> index b7c9aea..511cce9 100644
> --- a/fs/xfs/xfs_sb.c
> +++ b/fs/xfs/xfs_sb.c
> @@ -288,6 +288,7 @@ xfs_mount_validate_sb(
> sbp->sb_inodelog < XFS_DINODE_MIN_LOG ||
> sbp->sb_inodelog > XFS_DINODE_MAX_LOG ||
> sbp->sb_inodesize != (1 << sbp->sb_inodelog) ||
> + sbp->sb_inopblock != howmany(sbp->sb_blocksize,sbp->sb_inodesize) ||
> (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog) ||
> (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE) ||
> (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE) ||
>
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