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From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     stephen@networkplumber.org
Cc:     kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com,
        wei.liu@kernel.org, decui@microsoft.com, davem@davemloft.net,
        kuba@kernel.org, ast@kernel.org, daniel@iogearbox.net,
        hawk@kernel.org, john.fastabend@gmail.com, andrii@kernel.org,
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        kpsingh@kernel.org, linux-hyperv@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        bpf@vger.kernel.org, Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: Re: [PATCH] hv_netvsc: Add check for kvmalloc_array
Date:   Fri, 11 Mar 2022 11:20:59 +0800
Message-Id: <20220311032059.2038014-1-jiasheng@iscas.ac.cn>
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On Fri, 11 Mar 2022 11:00:24 +0800
Stephen Hemminger <stephen@networkplumber.org> wrote:
>> +	if (!pcpu_sum) {
>> +		for (j = 0; j < i; j++)
>> +			data[j] = 0;
>> +		return
> 
> Why is unrolled zero (memset) needed? The data area comes from
> ethtool_get_stats and is already zeroed (vzalloc).
> 
> 
> There does look like at TOCTOU error here with on the number of stats.
> Code doesn't look hotplug safe.
> Not sure, but that issue might have been raised during review.

I unrolled the 'data area' since the three 'for loops' before
have already assigned the value to the data area.
And I have not found any review about it.

Thanks,
Jiang