Re: [PATCH] ipvs: Keep skb->sk when allocating headroom on tunnel xmit
From: Simon Horman
Date: Tue Nov 11 2014 - 21:22:26 EST
On Sat, Nov 08, 2014 at 08:16:58AM +0200, Julian Anastasov wrote:
>
> Hello,
>
> On Fri, 7 Nov 2014, Calvin Owens wrote:
>
> > 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?
>
> Sorry, it seems I was checking old branch.
>
> Simon, please apply.
>
> Acked-by: Julian Anastasov <ja@xxxxxx>
Thanks, done.
> > > - 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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