Re: [PATCH net] r8152: drop the tx packet with invalid length

[Eric Dumazet <eric.dumazet@gmail.com>]

On Wed, 2014-11-26 at 17:56 +0800, Hayes Wang wrote:
> Drop the tx packet which is more than the size of agg_buf_sz. When
> creating a bridge with the device, we may get the tx packet with
> TSO and the length is more than the gso_max_size which is set by
> the driver through netif_set_gso_max_size(). Such packets couldn't
> be transmitted and should be dropped directly.
> 
> Signed-off-by: Hayes Wang <hayeswang@realtek.com>
> ---
>  drivers/net/usb/r8152.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
> index c6554c7..ebdaff7 100644
> --- a/drivers/net/usb/r8152.c
> +++ b/drivers/net/usb/r8152.c
> @@ -1897,6 +1897,15 @@ static netdev_tx_t rtl8152_start_xmit(struct sk_buff *skb,
>  {
>  	struct r8152 *tp = netdev_priv(netdev);
>  
> +	if ((skb->len + sizeof(struct tx_desc)) > agg_buf_sz) {
> +		struct net_device_stats *stats = &netdev->stats;
> +
> +		dev_kfree_skb_any(skb);
> +		stats->tx_dropped++;
> +		WARN_ON_ONCE(1);
> +		return NETDEV_TX_OK;
> +	}
> +
>  	skb_tx_timestamp(skb);
>  
>  	skb_queue_tail(&tp->tx_queue, skb);

Looks like a candidate for ndo_gso_check(), so that we do not drop, but
instead segment from netif_needs_gso()/validate_xmit_skb()