nbd: Add the maximum limit of allocated index in nbd_dev_add

If the index allocated by idr_alloc greater than MINORMASK >> part_shift,
the device number will overflow, resulting in failure to create a block
device.

Fix it by imiting the size of the max allocation.

Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230605122159.2134384-1-zhongjinghua@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Zhong Jinghua 2023-06-05 20:21:59 +08:00 committed by Jens Axboe
parent ddf63516d8
commit f12bc113ce

View File

@ -1776,7 +1776,8 @@ static struct nbd_device *nbd_dev_add(int index, unsigned int refs)
if (err == -ENOSPC)
err = -EEXIST;
} else {
err = idr_alloc(&nbd_index_idr, nbd, 0, 0, GFP_KERNEL);
err = idr_alloc(&nbd_index_idr, nbd, 0,
(MINORMASK >> part_shift) + 1, GFP_KERNEL);
if (err >= 0)
index = err;
}