xfs: check for bogus values in btree block headers

When we're reading a btree block, make sure that what we retrieved
matches the owner and level; and has a plausible number of records.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Darrick J. Wong 2016-12-05 12:33:54 +11:00 committed by Dave Chinner
parent d2a047f31e
commit bb3be7e7c1

View file

@ -1769,8 +1769,28 @@ xfs_btree_lookup_get_block(
if (error)
return error;
/* Check the inode owner since the verifiers don't. */
if (xfs_sb_version_hascrc(&cur->bc_mp->m_sb) &&
(cur->bc_flags & XFS_BTREE_LONG_PTRS) &&
be64_to_cpu((*blkp)->bb_u.l.bb_owner) !=
cur->bc_private.b.ip->i_ino)
goto out_bad;
/* Did we get the level we were looking for? */
if (be16_to_cpu((*blkp)->bb_level) != level)
goto out_bad;
/* Check that internal nodes have at least one record. */
if (level != 0 && be16_to_cpu((*blkp)->bb_numrecs) == 0)
goto out_bad;
xfs_btree_setbuf(cur, level, bp);
return 0;
out_bad:
*blkp = NULL;
xfs_trans_brelse(cur->bc_tp, bp);
return -EFSCORRUPTED;
}
/*