netdev - Re: [PATCH net v2] ibmveth: set correct gso_size and gso

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Date:   Fri, 09 Dec 2016 19:28:41 -0800
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     Thomas Falcon <tlfalcon@...ux.vnet.ibm.com>
Cc:     netdev@...r.kernel.org, brking@...ux.vnet.ibm.com,
        pradeeps@...ux.vnet.ibm.com, marcelo.leitner@...il.com,
        jmaxwell37@...il.com, zdai@...ibm.com
Subject: Re: [PATCH net v2] ibmveth: set correct gso_size and gso_type

On Fri, 2016-12-09 at 19:31 -0600, Thomas Falcon wrote:
> This patch is based on an earlier one submitted
> by Jon Maxwell with the following commit message:
> 

> +					DIV_ROUND_UP(skb->len - hdr_len, mss);
> +	} else if (offset) {
> +		skb_shinfo(skb)->gso_size = ntohs(tcph->check);
> +		skb_shinfo(skb)->gso_segs =
> +				DIV_ROUND_UP(skb->len - hdr_len,
> +					     skb_shinfo(skb)->gso_size);
> +		tcph->check = 0;
> +	}

Are you sure that tcph->check could never be 0 on some cases ?

That would crash on a divide by 0