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From: Eric Dumazet <eric.dumazet@gmail•com>
To: Stephen Hemminger <stephen@networkplumber•org>,
	Sheng Lan <lansheng@huawei•com>
Cc: davem@davemloft•net, netdev@vger•kernel.org,
	netem@lists•linux-foundation.org, xuhanbing@huawei•com,
	zhengshaoyu@huawei•com, jiqin.ji@huawei•com,
	liuzhiqiang26@huawei•com, yuehaibing@huawei•com
Subject: Re: [PATCH] net: netem: fix skb length BUG_ON in __skb_to_sgvec
Date: Tue, 26 Feb 2019 08:08:17 -0800	[thread overview]
Message-ID: <655edad3-d09a-ea0e-e230-557bdedb712d@gmail.com> (raw)
In-Reply-To: <20190226075906.103fa072@shemminger-XPS-13-9360>




On 02/26/2019 07:59 AM, Stephen Hemminger wrote:
> 
> 
> Maybe the fix is to stop TSO fragment from overwriting by doing something like:
> 
> diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
> index 730bc44dbad9..5fe91d0224f6 100644
> --- a/net/ipv4/tcp_output.c
> +++ b/net/ipv4/tcp_output.c
> @@ -1856,7 +1856,7 @@ static int tso_fragment(struct sock *sk, enum tcp_queue tcp_queue,
>  	u8 flags;
>  
>  	/* All of a TSO frame must be composed of paged data.  */
> -	if (skb->len != skb->data_len)
> +	if (skb->len != skb->data_len || skb_cloned(skb))
>  		return tcp_fragment(sk, tcp_queue, skb, len, mss_now, gfp);
>  
>  	buff = sk_stream_alloc_skb(sk, 0, gfp, true);
> 


tso_fragment() is only called with packets that were not yet transmit.




      reply	other threads:[~2019-02-26 16:08 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-25 14:49 [PATCH] net: netem: fix skb length BUG_ON in __skb_to_sgvec Sheng Lan
2019-02-25 16:01 ` Stephen Hemminger
2019-02-26 13:02   ` Sheng Lan
2019-02-26 15:52     ` Eric Dumazet
2019-02-27 11:26       ` Sheng Lan
2019-02-27 15:53         ` Eric Dumazet
2019-02-26 15:59     ` Stephen Hemminger
2019-02-26 16:08       ` Eric Dumazet [this message]

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