Re: [PATCH 64/86] IP_GRE: Fix kernel panic in IP_GRE with GRE csum.

[Ben Hutchings]

On Tue, 2013-03-26 at 13:22 -0400, Steven Rostedt wrote:

> 3.6.11.1 stable review patch.
> If anyone has any objections, please let me know.
> 
> ------------------
> 
> From: Pravin B Shelar <pshelar@xxxxxxxxxx>
> 
> [ Upstream commit d0a7cc630a337b0f56dc145e7eb6232852b14dd4 ]
> 
> Due to IP_GRE GSO support, GRE can recieve non linear skb which
> results in panic in case of GRE_CSUM.  Following patch fixes it by
> using correct csum API.
> 
> Bug introduced in commit 6b78f16e4bdde3936b (gre: add GSO support)

That commit went into 3.7, so I don't think this fix is needed for 3.6.

Ben.

> Signed-off-by: Pravin B Shelar <pshelar@xxxxxxxxxx>
> Acked-by: Eric Dumazet <edumazet@xxxxxxxxxx>
> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> ---
>  net/ipv4/ip_gre.c |    6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
> index b062a98..3ee08ce 100644
> --- a/net/ipv4/ip_gre.c
> +++ b/net/ipv4/ip_gre.c
> @@ -946,8 +946,12 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev
>  			ptr--;
>  		}
>  		if (tunnel->parms.o_flags&GRE_CSUM) {
> +			int offset = skb_transport_offset(skb);
> +
>  			*ptr = 0;
> -			*(__sum16 *)ptr = ip_compute_csum((void *)(iph+1), skb->len - sizeof(struct iphdr));
> +			*(__sum16 *)ptr = csum_fold(skb_checksum(skb, offset,
> +								 skb->len - offset,
> +								 0));
>  		}
>  	}
>  

-- 
Ben Hutchings
I'm not a reverse psychological virus.  Please don't copy me into your sig.

Attachment: signature.asc
Description: This is a digitally signed message part