[XFS] prevent panic during log recovery due to bogus op_hdr length

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.

SGI-PV: 974151
SGI-Modid: xfs-linux-melb:xfs-kern:30318a

Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 071672969421..b82d5d4d2462 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -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");
+                                WARN_ON(1);
+                                return (XFS_ERROR(EIO));
+                        }
                         flags = ohead->oh_flags & ~XLOG_END_TRANS;
                         if (flags & XLOG_WAS_CONT_TRANS)
                                 flags &= ~XLOG_CONTINUE_TRANS;