Re: [PATCH] ipvs: Keep skb->sk when allocating headroom on tunnel xmit

From: Julian Anastasov
Date: Wed Nov 05 2014 - 04:31:47 EST



Hello,

On Tue, 4 Nov 2014, Calvin Owens wrote:

> ip_vs_prepare_tunneled_skb() ignores ->sk when allocating a new
> skb, either unconditionally setting ->sk to NULL or allowing
> the uninitialized ->sk from a newly allocated skb to leak through
> to the caller.
>
> This patch properly copies ->sk and increments its reference count.
>
> Signed-off-by: Calvin Owens <calvinowens@xxxxxx>

Good catch. Please, extend your patch to
fix also the second place that has such error,
ip_vs_tunnel_xmit_v6. This call is missing from long time,
it was not needed. But commits that allow skb->sk (local
clients) already need it, eg.

- f2428ed5e7bc89c7 ("ipvs: load balance ipv6 connections from a local
process"), 2.6.28
- 4856c84c1358b798 ("ipvs: load balance IPv4 connections from a local
process"), 2.6.28

> ---
> net/netfilter/ipvs/ip_vs_xmit.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
> index 437a366..bd90bf8 100644
> --- a/net/netfilter/ipvs/ip_vs_xmit.c
> +++ b/net/netfilter/ipvs/ip_vs_xmit.c
> @@ -846,6 +846,8 @@ ip_vs_prepare_tunneled_skb(struct sk_buff *skb, int skb_af,
> new_skb = skb_realloc_headroom(skb, max_headroom);
> if (!new_skb)
> goto error;
> + if (skb->sk)
> + skb_set_owner_w(new_skb, skb->sk);
> consume_skb(skb);
> skb = new_skb;
> }

Regards

--
Julian Anastasov <ja@xxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/