Re: [PATCH] cls_rsvp: add sanity check for the packet length

[jamal <hadi@cyberus.ca>]

On Wed, 2010-08-04 at 16:55 +0800, Changli Gao wrote:
> The packet length should be checked before the packet data is dereferenced.
> 
> Signed-off-by: Changli Gao <xiaosuo@gmail.com>
> ---
>  net/sched/cls_rsvp.h |   10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> diff --git a/net/sched/cls_rsvp.h b/net/sched/cls_rsvp.h
> index dd9414e..4fa119d 100644
> --- a/net/sched/cls_rsvp.h
> +++ b/net/sched/cls_rsvp.h
> @@ -143,9 +143,17 @@ static int rsvp_classify(struct sk_buff *skb, struct tcf_proto *tp,
>  	u8 tunnelid = 0;
>  	u8 *xprt;
>  #if RSVP_DST_LEN == 4
> -	struct ipv6hdr *nhptr = ipv6_hdr(skb);
> +	struct ipv6hdr *nhptr;
> +
> +	if (!pskb_may_pull(skb, skb_network_offset(skb) + sizeof(*nhptr)))
> +		return -1;
> +	nhptr = ipv6_hdr(skb);
>  #else
>  	struct iphdr *nhptr = ip_hdr(skb);
> +
> +	if (!pskb_may_pull(skb, skb_network_offset(skb) + sizeof(*nhptr)))
> +		return -1;
> +	nhptr = ip_hdr(skb);
>  #endif

Maybe a good time to move nhptr declaration outside #if since it is used
in #else as well.

Otherwise:
Acked-by: Jamal Hadi Salim <hadi@cyberus.ca>

cheers,
jamal