[Qemu-devel] 答复: [PATCH v2] net: ne2000: check ring buffer control registers

[yanghongke]

Good day to you!

        After my test, I find that the issue is fixed with this patch.
        When receiving packet, ne2000_buffer_full return 1, ne2000_receive 
immediately return -1,so it avoid infinite loop or OOB r/w access issues.

-----邮件原件-----
发件人: Jason Wang [mailto:jasow...@redhat.com] 
发送时间: 2016年2月24日 16:13
收件人: P J P; Qemu Developers
抄送: yanghongke; Prasad J Pandit
主题: Re: [PATCH v2] net: ne2000: check ring buffer control registers



On 02/24/2016 02:11 PM, P J P wrote:
> From: Prasad J Pandit <p...@fedoraproject.org>
>
> Ne2000 NIC uses ring buffer of NE2000_MEM_SIZE(49152) bytes to process 
> network packets. Registers PSTART & PSTOP define ring buffer size & 
> location. Setting these registers to invalid values could lead to 
> infinite loop or OOB r/w access issues. Add check to avoid it.
>
> Reported-by: Yang Hongke <yanghon...@huawei.com>
> Signed-off-by: Prasad J Pandit <p...@fedoraproject.org>
> ---
>  hw/net/ne2000.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> Update per review:
>   -> 
> https://lists.gnu.org/archive/html/qemu-devel/2016-02/msg05522.html
>
> diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c index b032212..ced4666 
> 100644
> --- a/hw/net/ne2000.c
> +++ b/hw/net/ne2000.c
> @@ -154,6 +154,10 @@ static int ne2000_buffer_full(NE2000State *s)  {
>      int avail, index, boundary;
>  
> +    if (s->stop <= s->start) {
> +        return 1;
> +    }
> +
>      index = s->curpag << 8;
>      boundary = s->boundary << 8;
>      if (index < boundary)

Hongke, would you mind to test this patch to see if it fixes your issue and add 
a "Tested-by" tag?

Thanks