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

[Calvin Owens]

On 11/05/2014 01:21 AM, Julian Anastasov wrote:
> 	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.

I'm not sure where exactly you mean: ip_vs_tunnel_xmit_v6() calls
ip_vs_prepare_tunneled_skb() to do the allocation, so this patch covers 
that case.

In older versions of the kernel, ip_vs_tunnel_xmit_v6() does it 
directly, could that be what you're looking at?

> - 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>
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