Oops in 2.5.44's fs/block_dev.c:do_open() when trying to mount a badly formated floppy

Offending code is:

    663                 if (bdev->bd_invalidated)
    664                         rescan_partitions(disk, bdev);
    665         } else {
    666                 down(&bdev->bd_contains->bd_sem);
    667                 bdev->bd_contains->bd_part_count++;
    668                 if (!bdev->bd_openers) {
    669                         struct hd_struct *p;
    670                         p = disk->part + part - 1;
                                    ^^^^^^^^^^

                        this is NULL when the floppy is badly formatted

The problem is not present in 2.5.43, but is also present in 2.5.44-ac1

Luc Van Oostenryck