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Message-ID: <f1795a37-d615-4260-ac29-97f0d0ad3c8f@bytedance.com>
Date:   Fri, 20 Oct 2023 10:23:33 +0800
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User-Agent: Mozilla Thunderbird
Subject: Re: Re: PING: [PATCH] virtio-blk: fix implicit overflow on
 virtio_max_dma_size
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To:     "Michael S. Tsirkin" <mst@redhat.com>
Cc:     jasowang@redhat.com, xuanzhuo@linux.alibaba.com,
        virtualization@lists.linux-foundation.org, axboe@kernel.dk,
        linux-kernel@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
        Stefan Hajnoczi <stefanha@redhat.com>,
        Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
        linux-block@vger.kernel.org
References: <20230904061045.510460-1-pizhenwei@bytedance.com>
 <dedde8ee-6edb-4950-aa8b-e89e025440b7@bytedance.com>
 <20231019055134-mutt-send-email-mst@kernel.org>
From:   zhenwei pi <pizhenwei@bytedance.com>
In-Reply-To: <20231019055134-mutt-send-email-mst@kernel.org>
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Cc Paolo, Stefan, Xuan and linux-block.

On 10/19/23 17:52, Michael S. Tsirkin wrote:
> On Thu, Oct 19, 2023 at 05:43:55PM +0800, zhenwei pi wrote:
>> Hi Michael,
>>
>> This seems to have been ignored as you suggested.
>>
>> LINK: https://www.spinics.net/lists/linux-virtualization/msg63015.html
> 
> Pls Cc more widely then:
> 
> Paolo Bonzini <pbonzini@redhat.com> (reviewer:VIRTIO BLOCK AND SCSI DRIVERS)
> Stefan Hajnoczi <stefanha@redhat.com> (reviewer:VIRTIO BLOCK AND SCSI DRIVERS)
> Xuan Zhuo <xuanzhuo@linux.alibaba.com> (reviewer:VIRTIO CORE AND NET DRIVERS)
> Jens Axboe <axboe@kernel.dk> (maintainer:BLOCK LAYER)
> linux-block@vger.kernel.org (open list:BLOCK LAYER)
> 
> would all be good people to ask to review this.
> 
> 
>> 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
> 

-- 
zhenwei pi