Re: [PATCH] net: ipv6: check net in ip6_call_ra_chain

From: David Miller
Date: Thu Feb 28 2019 - 16:02:17 EST


From: fruggeri@xxxxxxxxxx (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 <maxim@xxxxxxxxxx>
> Signed-off-by: Maxim Martynov <maxim@xxxxxxxxxx>
> Signed-off-by: Francesco Ruggeri <fruggeri@xxxxxxxxxx>

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.