On Wed, Jul 25, 2018 at 04:33:36PM -0500, Bill O'Donnell wrote:
> Current sb verifier doesn't check bounds on sb_fdblocks and sb_ifree.
> Add sanity checks for these parameters.
>
> Signed-off-by: Bill O'Donnell <billodo@xxxxxxxxxx>
> ---
> v3: eliminate need for additional write_flag, doing those
> unique checks in xfs_sb_write_verify()
> v2: make extra sanity checks exclusive to writes
>
>
> fs/xfs/libxfs/xfs_sb.c | 38 ++++++++++++++++++++++++++++----------
> 1 file changed, 28 insertions(+), 10 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
> index b3ad15956366..f583fb8a10e1 100644
> --- a/fs/xfs/libxfs/xfs_sb.c
> +++ b/fs/xfs/libxfs/xfs_sb.c
> @@ -599,22 +599,16 @@ xfs_sb_to_disk(
> static int
> xfs_sb_verify(
> struct xfs_buf *bp,
> + struct xfs_sb *sb,
> bool check_version)
> {
> struct xfs_mount *mp = bp->b_target->bt_mount;
> - struct xfs_sb sb;
> -
> - /*
> - * Use call variant which doesn't convert quota flags from disk
> - * format, because xfs_mount_validate_sb checks the on-disk flags.
> - */
> - __xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false);
>
> /*
> * Only check the in progress field for the primary superblock as
> * mkfs.xfs doesn't clear it from secondary superblocks.
> */
> - return xfs_mount_validate_sb(mp, &sb,
> + return xfs_mount_validate_sb(mp, sb,
> bp->b_maps[0].bm_bn == XFS_SB_DADDR,
> check_version);
> }
> @@ -637,6 +631,7 @@ xfs_sb_read_verify(
> {
> struct xfs_mount *mp = bp->b_target->bt_mount;
> struct xfs_dsb *dsb = XFS_BUF_TO_SBP(bp);
> + struct xfs_sb sb;
> int error;
>
> /*
> @@ -657,7 +652,13 @@ xfs_sb_read_verify(
> }
> }
> }
> - error = xfs_sb_verify(bp, true);
> +
> + /*
> + * Use call variant which doesn't convert quota flags from disk
> + * format, because xfs_mount_validate_sb checks the on-disk flags.
> + */
> + __xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false);
> + error = xfs_sb_verify(bp, &sb, true);
>
> out_error:
> if (error == -EFSCORRUPTED || error == -EFSBADCRC)
> @@ -693,9 +694,26 @@ xfs_sb_write_verify(
> {
> struct xfs_mount *mp = bp->b_target->bt_mount;
> struct xfs_buf_log_item *bip = bp->b_log_item;
> + struct xfs_sb sb;
> int error;
>
> - error = xfs_sb_verify(bp, false);
> + /*
> + * Use call variant which doesn't convert quota flags from disk
> + * format, because xfs_mount_validate_sb checks the on-disk flags.
> + */
> + __xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false);
> +
> + error = xfs_sb_verify(bp, &sb, false);
> +
> + /* Additional sb sanity checks for writes */
> + if (!error) {
> + if (sb.sb_fdblocks > sb.sb_dblocks ||
> + sb.sb_ifree > sb.sb_icount) {
> + xfs_notice(mp, "SB sanity check failed");
> + error = -EFSCORRUPTED;
> + }
> + }
On the off chance that some day we add more write-time checks, could you
please structure this the usual way?
error = xfs_sb_verify(bp, &sb, false);
if (error)
goto err;
if (sb.sb_fdblocks > sb.sb_dblocks || sb.sb_ifree > sb.sb_icount) {
xfs_notice(mp, "SB summary counter sanity check failed");
error = -EFSCORRUPTED;
goto err;
}
err:
if (error) {
xfs_verifier_error(bp, error, __this_address);
return;
}
}
Other than that, this looks ok to me.
--D
> +
> if (error) {
> xfs_verifier_error(bp, error, __this_address);
> return;
> --
> 2.17.1
>
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