summaryrefslogtreecommitdiff
path: root/drivers/block
diff options
context:
space:
mode:
authorYu Kuai <yukuai3@huawei.com>2021-11-02 09:52:35 +0800
committerJens Axboe <axboe@kernel.dk>2021-11-02 10:50:27 -0600
commit940c264984fd1457918393c49674f6b39ee16506 (patch)
tree47e9ff9067a32c98fa597dbc0f258d7bd7d5f9a4 /drivers/block
parente4c4871a73944353ea23e319de27ef73ce546623 (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>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/nbd.c6
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;
}