diff options
| author | Yu Kuai <yukuai3@huawei.com> | 2021-11-02 04:52:35 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-18 21:17:05 +0300 |
| commit | e99270d7f2731f532831923b9dd35b7be79158fe (patch) | |
| tree | 969e9cdcd66d2fff5ea021df31b216ad464f6447 /drivers/block | |
| parent | 795e6b378692d8cf6fd4d1328d8f3e39c36c1e12 (diff) | |
| download | linux-e99270d7f2731f532831923b9dd35b7be79158fe.tar.xz | |
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>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/nbd.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 0d820c4dec17..577c7dba5d78 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1749,11 +1749,11 @@ static struct nbd_device *nbd_dev_add(int index, unsigned int refs) disk->major = NBD_MAJOR; /* Too big first_minor can cause duplicate creation of - * sysfs files/links, since MKDEV() expect that the max bits of - * first_minor is 20. + * sysfs files/links, since index << part_shift might overflow, or + * MKDEV() expect that the max bits of first_minor is 20. */ disk->first_minor = index << part_shift; - if (disk->first_minor > MINORMASK) { + if (disk->first_minor < index || disk->first_minor > MINORMASK) { err = -EINVAL; goto out_free_idr; } |