2014-11-05 00:39:12

by Calvin Owens

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

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 <[email protected]>
---
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;
}
--
2.1.1

2014-11-05 09:31:44

by Julian Anastasov

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

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 <[email protected]>

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 <[email protected]>

2014-11-07 22:13:32

by Calvin Owens

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

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 <[email protected]>
>
> 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 <[email protected]>
>

2014-11-08 06:17:20

by Julian Anastasov

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

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 <[email protected]>
> >
> > 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 <[email protected]>

> > - 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 <[email protected]>

2014-11-12 02:22:22

by Simon Horman

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

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 <[email protected]>
> > >
> > > 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 <[email protected]>

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 <[email protected]>
>