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

Christoph Hellwig
2007-12-14T20:31:11Z

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?