From: Zhong Jinghua zhongjinghua@huawei.com
[ Upstream commit f12bc113ce904777fd6ca003b473b427782b3dde ]
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.... Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/block/nbd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 28024248a7b53..5a07964a1e676 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1646,7 +1646,8 @@ static int nbd_dev_add(int index) 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; }