• Dave Chinner's avatar
    xfs: fix _xfs_buf_find oops on blocks beyond the filesystem end · eb178619
    Dave Chinner authored
    When _xfs_buf_find is passed an out of range address, it will fail
    to find a relevant struct xfs_perag and oops with a null
    dereference. This can happen when trying to walk a filesystem with a
    metadata inode that has a partially corrupted extent map (i.e. the
    block number returned is corrupt, but is otherwise intact) and we
    try to read from the corrupted block address.
    
    In this case, just fail the lookup. If it is readahead being issued,
    it will simply not be done, but if it is real read that fails we
    will get an error being reported.  Ideally this case should result
    in an EFSCORRUPTED error being reported, but we cannot return an
    error through xfs_buf_read() or xfs_buf_get() so this lookup failure
    may result in ENOMEM or EIO errors being reported instead.
    Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
    Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
    Reviewed-by: default avatarBen Myers <bpm@sgi.com>
    Signed-off-by: default avatarBen Myers <bpm@sgi.com>
    eb178619
xfs_buf.c 41.2 KB