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Message-ID: <dedde8ee-6edb-4950-aa8b-e89e025440b7@bytedance.com>
Date:   Thu, 19 Oct 2023 17:43:55 +0800
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Subject: PING: [PATCH] virtio-blk: fix implicit overflow on
 virtio_max_dma_size
Content-Language: en-US
To:     mst@redhat.com
Cc:     jasowang@redhat.com, xuanzhuo@linux.alibaba.com,
        virtualization@lists.linux-foundation.org, axboe@kernel.dk,
        linux-kernel@vger.kernel.org
References: <20230904061045.510460-1-pizhenwei@bytedance.com>
From:   zhenwei pi <pizhenwei@bytedance.com>
In-Reply-To: <20230904061045.510460-1-pizhenwei@bytedance.com>
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Hi Michael,

This seems to have been ignored as you suggested.

LINK: https://www.spinics.net/lists/linux-virtualization/msg63015.html

On 9/4/23 14:10, zhenwei pi wrote:
> The following codes have an implicit conversion from size_t to u32:
> (u32)max_size = (size_t)virtio_max_dma_size(vdev);
> 
> This may lead overflow, Ex (size_t)4G -> (u32)0. Once
> virtio_max_dma_size() has a larger size than U32_MAX, use U32_MAX
> instead.
> 
> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> ---
>   drivers/block/virtio_blk.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 1fe011676d07..4a4b9bad551e 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -1313,6 +1313,7 @@ static int virtblk_probe(struct virtio_device *vdev)
>   	u16 min_io_size;
>   	u8 physical_block_exp, alignment_offset;
>   	unsigned int queue_depth;
> +	size_t max_dma_size;
>   
>   	if (!vdev->config->get) {
>   		dev_err(&vdev->dev, "%s failure: config access disabled\n",
> @@ -1411,7 +1412,8 @@ static int virtblk_probe(struct virtio_device *vdev)
>   	/* No real sector limit. */
>   	blk_queue_max_hw_sectors(q, UINT_MAX);
>   
> -	max_size = virtio_max_dma_size(vdev);
> +	max_dma_size = virtio_max_dma_size(vdev);
> +	max_size = max_dma_size > U32_MAX ? U32_MAX : max_dma_size;
>   
>   	/* Host can optionally specify maximum segment size and number of
>   	 * segments. */

-- 
zhenwei pi