Re: [PATCH] prevent panic during log recovery due to bogus operation header length

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

On Wed, Dec 12, 2007 at 06:07:47PM +1100, Lachlan McIlroy wrote:
> A problem was reported where a system panicked in log recovery due
> to a corrupt log record.  The cause of the corruption is not known
> but this change will at least prevent a crash for this specific
> scenario.  Log recovery definitely needs some more work in this area.
>
> Lachlan

> --- fs/xfs/xfs_log_recover.c_1.332    2007-12-12 17:14:57.000000000 +1100
> +++ fs/xfs/xfs_log_recover.c  2007-12-12 17:15:42.000000000 +1100
> @@ -2912,7 +2912,12 @@ xlog_recover_process_data(
>                               xlog_recover_new_tid(&rhash[hash], tid,
>                                       be64_to_cpu(rhead->h_lsn));
>               } else {
> -                     ASSERT(dp + be32_to_cpu(ohead->oh_len) <= lp);
> +                     if (dp + be32_to_cpu(ohead->oh_len) > lp) {
> +                             xlog_warn(
> +                     "XFS: xlog_recover_process_data: bad length");
> +                             ASSERT(0);
> +                             return (XFS_ERROR(EIO));
> +                     }

this still gives a panic for debug builds..  Maybe this should become
a WARN_ON(1) instead?