2023-06-05 12:31:25

by zhongjinghua

Subject: [PATCH -next] nbd: Add the maximum limit of allocated index in nbd_dev_add

From: Zhong Jinghua <[email protected]>

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 <[email protected]>
---
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 592cfa8b765a..cb38477f359f 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -1770,7 +1770,8 @@ static struct nbd_device *nbd_dev_add(int index, unsigned int refs)
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;
}
--
2.31.1

2023-06-07 07:57:06

by Christoph Hellwig

Subject: Re: [PATCH -next] nbd: Add the maximum limit of allocated index in nbd_dev_add

Looks good:

Reviewed-by: Christoph Hellwig <[email protected]>

2023-06-07 14:29:52

by Jens Axboe

Subject: Re: [PATCH -next] nbd: Add the maximum limit of allocated index in nbd_dev_add

On Mon, 05 Jun 2023 20:21:59 +0800, Zhong Jinghua wrote:
> 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.
>
>
> [...]

Applied, thanks!

[1/1] nbd: Add the maximum limit of allocated index in nbd_dev_add
commit: f12bc113ce904777fd6ca003b473b427782b3dde

Best regards,
--
Jens Axboe