Commit 4c434392 authored by Li Nan's avatar Li Nan Committed by Jens Axboe
Browse files

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 e338924b ("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: e338924b ("block: check minor range in device_add_disk()")
Signed-off-by: default avatarLi Nan <linan122@huawei.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231219075942.840255-1-linan666@huaweicloud.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 6c9b9708

block/genhd.c

+3 −1
Original line number Diff line number Diff line
@@ -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))