diff options
| author | Yu Kuai | 2021-11-02 09:52:35 +0800 |
|---|---|---|
| committer | Jens Axboe | 2021-11-02 10:50:27 -0600 |
| commit | 940c264984fd1457918393c49674f6b39ee16506 (patch) | |
| tree | 47e9ff9067a32c98fa597dbc0f258d7bd7d5f9a4 | |
| parent | e4c4871a73944353ea23e319de27ef73ce546623 (diff) | |
nbd: fix possible overflow for 'first_minor' in nbd_dev_add()
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>
| -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 29f9ac8817d7..a5e3ee28006f 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1808,11 +1808,11 @@ 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; } |