Subject: Re: [PATCH net] ipv6: no need to return rt->dst.error if it is not null entry.

From: Hangbin Liu <[email-masked]>
Date: Tue, 25 Jul 2017 15:32:02 +0800

On Mon, Jul 24, 2017 at 09:28:07PM -0600, David Ahern wrote:
> On 7/24/17 6:08 PM, Hangbin Liu wrote:
> > That's why I think we should remove both rt->dst.error and ip6_null_entry
> > check in inet6_rtm_getroute(). And even further, remove the ip6_null_entry
> > check in rt6_dump_route().
> 
> git blame net/ipv6/route.c
> 
> find the commits and review.

Hi David,

Sorry, would you like to give me more hints?

I saw your commit 1f17e2f2c8a8 ("net: ipv6: ignore null_entry on route
dumps"). But I think this issue has been fixed by

2f460933f58e ("ipv6: initialize route null entry in addrconf_init()") and
242d3a49a2a1 ("ipv6: reorder ip6_route_dev_notifier after ipv6_dev_notf")

I use a reproducer which add unreachable route in netns with lo down. And I
could not trigger Panic in the fixed kernel. That's why I think we could
remove ip6_null_entry check in rt6_dump_route().

Please correct me if I make any mistake.

Thanks
Hangbin