block: add check of 'minors' and 'first_minor' in device_add_disk()

'first_minor' represents the starting minor number of disks, and
'minors' represents the number of partitions in the device. Neither
of them can be greater than MINORMASK + 1.

Commit e338924bd0 ("block: check minor range in device_add_disk()")
only added the check of 'first_minor + minors'. However, their sum might
be less than MINORMASK but their values are wrong. Complete the checks now.

Fixes: e338924bd0 ("block: check minor range in device_add_disk()")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231219075942.840255-1-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Li Nan 2023-12-19 15:59:42 +08:00 committed by Jens Axboe
parent 6c9b97085c
commit 4c434392c4

View File

@ -432,7 +432,9 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
DISK_MAX_PARTS);
disk->minors = DISK_MAX_PARTS;
}
if (disk->first_minor + disk->minors > MINORMASK + 1)
if (disk->first_minor > MINORMASK ||
disk->minors > MINORMASK + 1 ||
disk->first_minor + disk->minors > MINORMASK + 1)
goto out_exit_elevator;
} else {
if (WARN_ON(disk->minors))