[ovs-dev] [PATCH v2 1/4] ip6_gre: Fix a bug that clears address bits

[Gregory Rose]

On 8/15/2018 6:24 AM, Yifeng Sun wrote:
> In compatable gre module, skb->cb is solely used as ovs_gso_cb.
> However, IPCB(skb) also points to skb->cb. IPCB(skb)->flags overlaps
> with ovs_gso_cb.tun_dst. As a result, this bug clears the 16-23 bit
> in the address of ovs_gso_cb.tun_dst and causes kernel to crash.
>
> Signed-off-by: Yifeng Sun <pkusunyifeng at gmail.com>
> ---
> v1->v2: Improved commit message and fixed __gre6_xmit, thanks Greg!
>
>   datapath/linux/compat/ip6_gre.c | 4 ----
>   1 file changed, 4 deletions(-)
>
> diff --git a/datapath/linux/compat/ip6_gre.c b/datapath/linux/compat/ip6_gre.c
> index 54a76ab..3904455 100644
> --- a/datapath/linux/compat/ip6_gre.c
> +++ b/datapath/linux/compat/ip6_gre.c
> @@ -876,9 +876,6 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
>   	struct tnl_ptk_info tpi;
>   	__be16 protocol;
>   
> -	if (dev->type == ARPHRD_ETHER)
> -		IPCB(skb)->flags = 0;
> -
>   	if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
>   		fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
>   	else
> @@ -1146,7 +1143,6 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
>   		goto tx_err;
>   
>   	t->parms.o_flags &= ~TUNNEL_KEY;
> -	IPCB(skb)->flags = 0;
>   
>   	tun_info = ovs_skb_tunnel_info(skb);
>   	if (unlikely(!tun_info ||

Looks good.

Tested-by: Greg Rose <gvrose8192 at gmail.com>
Reviewed-by: Greg Rose <gvrose8192 at gmail.com>