On Wed, 24 Jan 2018 08:29:24 -0800 David Ahern <[email protected]> wrote:
> IPv6 allows routes to be installed when the device is not up (admin up). > Worse, it does not mark it as LINKDOWN. IPv4 does not allow it and really > there is no reason for IPv6 to allow it, so check the flags and deny if > device is admin down. > > Signed-off-by: David Ahern <[email protected]> > --- > v2 > - missed setting err to -ENETDOWN (thanks for catching that Roopa) > > net/ipv6/route.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/net/ipv6/route.c b/net/ipv6/route.c > index f85da2f1e729..4e8fab766018 100644 > --- a/net/ipv6/route.c > +++ b/net/ipv6/route.c > @@ -2734,6 +2734,12 @@ static struct rt6_info *ip6_route_info_create(struct > fib6_config *cfg, > if (!dev) > goto out; > > + err = -ENETDOWN; > + if (!(dev->flags & IFF_UP)) { > + NL_SET_ERR_MSG(extack, "Nexthop device is not up"); > + goto out; > + } > + > if (!ipv6_addr_any(&cfg->fc_prefsrc)) { > if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) { > NL_SET_ERR_MSG(extack, "Invalid source address"); This looks like a good idea. There are two equal ways to check for admin up. Either the dev flags or look at link state via netif_running(). Maybe the latter would be better.
