nbd: fix possible overflow for 'first_minor' in nbd_dev_add()
authorYu Kuai <yukuai3@huawei.com>
Tue, 2 Nov 2021 01:52:35 +0000 (09:52 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 18 Nov 2021 18:17:05 +0000 (19:17 +0100)
commite99270d7f2731f532831923b9dd35b7be79158fe
tree969e9cdcd66d2fff5ea021df31b216ad464f6447
parent795e6b378692d8cf6fd4d1328d8f3e39c36c1e12
nbd: fix possible overflow for 'first_minor' in nbd_dev_add()

[ Upstream commit 940c264984fd1457918393c49674f6b39ee16506 ]

If 'part_shift' is not zero, then 'index << part_shift' might
overflow to a value that is not greater than '0xfffff', then sysfs
might complains about duplicate creation.

Fixes: b0d9111a2d53 ("nbd: use an idr to keep track of nbd devices")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20211102015237.2309763-3-yebin10@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/block/nbd.c