Re: [PATCH] ip6_offload: check segs for NULL in ipv6_gso_segment.

[Eric Dumazet]

On Thu, 2016-12-01 at 14:06 +0100, Artem Savkov wrote:
> segs needs to be checked for being NULL in ipv6_gso_segment() before calling
> skb_shinfo(segs), otherwise kernel can run into a NULL-pointer dereference:


> Signed-off-by: Artem Savkov <asavkov@xxxxxxxxxx>
> ---
>  

> diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
> index 1fcf61f..89c59e6 100644
> --- a/net/ipv6/ip6_offload.c
> +++ b/net/ipv6/ip6_offload.c
> @@ -99,7 +99,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
>  		segs = ops->callbacks.gso_segment(skb, features);
>  	}
>  
> -	if (IS_ERR(segs))
> +	if (IS_ERR_OR_NULL(segs))
>  		goto out;
>  
>  	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);

Do you know when was this bug added ?

Are you sure this is the right fix ?

Which gso_segment() is returning NULL exactly ?

Thanks.