2019-02-28 19:03:25

by Francesco Ruggeri

[permalink] [raw]
Subject: [PATCH] net: ipv6: check net in ip6_call_ra_chain

ip6_call_ra_chain is called when IPv6 packet with Router Alert option
is forwarded.
It needs to check if the net of the socket is the same as the net of the
input device, otherwise the packet gets delivered to every IPv6 socket
listening for Router Alerts, no matter which network namespace it is in.

Suggested-by: Maxim Martynov <[email protected]>
Signed-off-by: Maxim Martynov <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>

---
net/ipv6/ip6_output.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 5f9fa0302b5a..3ed25e17dff3 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -299,7 +299,8 @@ static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
struct sock *sk = ra->sk;
if (sk && ra->sel == sel &&
(!sk->sk_bound_dev_if ||
- sk->sk_bound_dev_if == skb->dev->ifindex)) {
+ sk->sk_bound_dev_if == skb->dev->ifindex) &&
+ net_eq(sock_net(sk), dev_net(skb->dev))) {
if (last) {
struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
if (skb2)
--
2.19.1



2019-02-28 22:05:58

by David Miller

[permalink] [raw]
Subject: Re: [PATCH] net: ipv6: check net in ip6_call_ra_chain

From: [email protected] (Francesco Ruggeri)
Date: Thu, 28 Feb 2019 11:01:46 -0800

> ip6_call_ra_chain is called when IPv6 packet with Router Alert option
> is forwarded.
> It needs to check if the net of the socket is the same as the net of the
> input device, otherwise the packet gets delivered to every IPv6 socket
> listening for Router Alerts, no matter which network namespace it is in.
>
> Suggested-by: Maxim Martynov <[email protected]>
> Signed-off-by: Maxim Martynov <[email protected]>
> Signed-off-by: Francesco Ruggeri <[email protected]>

Right now someone using such a tool does get all RAs in the system.

Your change not only breaks them, but also gives them no method by
which to keep obtaining the same behavior.

I don't know what to do or suggest in this situation, but right now
I'm putting this patch on hold.

2019-02-28 23:37:34

by David Ahern

[permalink] [raw]
Subject: Re: [PATCH] net: ipv6: check net in ip6_call_ra_chain

On 2/28/19 2:02 PM, David Miller wrote:
> From: [email protected] (Francesco Ruggeri)
> Date: Thu, 28 Feb 2019 11:01:46 -0800
>
>> ip6_call_ra_chain is called when IPv6 packet with Router Alert option
>> is forwarded.
>> It needs to check if the net of the socket is the same as the net of the
>> input device, otherwise the packet gets delivered to every IPv6 socket
>> listening for Router Alerts, no matter which network namespace it is in.
>>
>> Suggested-by: Maxim Martynov <[email protected]>
>> Signed-off-by: Maxim Martynov <[email protected]>
>> Signed-off-by: Francesco Ruggeri <[email protected]>
>
> Right now someone using such a tool does get all RAs in the system.
>
> Your change not only breaks them, but also gives them no method by
> which to keep obtaining the same behavior.
>
> I don't know what to do or suggest in this situation, but right now
> I'm putting this patch on hold.
>

need an equivalent to NETLINK_LISTEN_ALL_NSID

2019-03-01 01:52:47

by Francesco Ruggeri

[permalink] [raw]
Subject: Re: [PATCH] net: ipv6: check net in ip6_call_ra_chain

On Thu, Feb 28, 2019 at 3:31 PM David Ahern <[email protected]> wrote:
>
> On 2/28/19 2:02 PM, David Miller wrote:
> > From: [email protected] (Francesco Ruggeri)
> > Date: Thu, 28 Feb 2019 11:01:46 -0800
> >
> >> ip6_call_ra_chain is called when IPv6 packet with Router Alert option
> >> is forwarded.
> >> It needs to check if the net of the socket is the same as the net of the
> >> input device, otherwise the packet gets delivered to every IPv6 socket
> >> listening for Router Alerts, no matter which network namespace it is in.
> >>
> >> Suggested-by: Maxim Martynov <[email protected]>
> >> Signed-off-by: Maxim Martynov <[email protected]>
> >> Signed-off-by: Francesco Ruggeri <[email protected]>
> >
> > Right now someone using such a tool does get all RAs in the system.
> >
> > Your change not only breaks them, but also gives them no method by
> > which to keep obtaining the same behavior.
> >
> > I don't know what to do or suggest in this situation, but right now
> > I'm putting this patch on hold.
> >
>
> need an equivalent to NETLINK_LISTEN_ALL_NSID

If that would be acceptable, we can look into it.

Thanks,
Francesco

2019-03-01 02:14:18

by David Miller

[permalink] [raw]
Subject: Re: [PATCH] net: ipv6: check net in ip6_call_ra_chain

From: Francesco Ruggeri <[email protected]>
Date: Thu, 28 Feb 2019 16:09:17 -0800

> On Thu, Feb 28, 2019 at 3:31 PM David Ahern <[email protected]> wrote:
>>
>> On 2/28/19 2:02 PM, David Miller wrote:
>> > From: [email protected] (Francesco Ruggeri)
>> > Date: Thu, 28 Feb 2019 11:01:46 -0800
>> >
>> >> ip6_call_ra_chain is called when IPv6 packet with Router Alert option
>> >> is forwarded.
>> >> It needs to check if the net of the socket is the same as the net of the
>> >> input device, otherwise the packet gets delivered to every IPv6 socket
>> >> listening for Router Alerts, no matter which network namespace it is in.
>> >>
>> >> Suggested-by: Maxim Martynov <[email protected]>
>> >> Signed-off-by: Maxim Martynov <[email protected]>
>> >> Signed-off-by: Francesco Ruggeri <[email protected]>
>> >
>> > Right now someone using such a tool does get all RAs in the system.
>> >
>> > Your change not only breaks them, but also gives them no method by
>> > which to keep obtaining the same behavior.
>> >
>> > I don't know what to do or suggest in this situation, but right now
>> > I'm putting this patch on hold.
>> >
>>
>> need an equivalent to NETLINK_LISTEN_ALL_NSID
>
> If that would be acceptable, we can look into it.

It is.