* Re: [PATCH v2] virtio-blk: Add validation for block size in config space
[not found] <20210615104810.151-1-xieyongji@bytedance.com>
@ 2021-06-15 15:27 ` Michael S. Tsirkin
0 siblings, 0 replies; only message in thread
From: Michael S. Tsirkin @ 2021-06-15 15:27 UTC (permalink / raw)
To: Xie Yongji; +Cc: axboe, linux-kernel, virtualization, linux-block, stefanha
On Tue, Jun 15, 2021 at 06:48:10PM +0800, Xie Yongji wrote:
> This ensures that we will not use an invalid block size
> in config space (might come from an untrusted device).
>
> Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
I'd say if device presents an unreasonable value,
and we want to ignore that, then we should not
negotiate VIRTIO_BLK_F_BLK_SIZE so that host knows.
So maybe move the logic to validate_features.
> ---
> drivers/block/virtio_blk.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index b9fa3ef5b57c..85ae3b27ea4b 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -827,7 +827,7 @@ static int virtblk_probe(struct virtio_device *vdev)
> err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
> struct virtio_blk_config, blk_size,
> &blk_size);
> - if (!err)
> + if (!err && blk_size >= SECTOR_SIZE && blk_size <= PAGE_SIZE)
> blk_queue_logical_block_size(q, blk_size);
> else
> blk_size = queue_logical_block_size(q);
> --
> 2.11.0
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