On 3/27/18 11:11 AM, Lorenzo Bianconi wrote:
> Do not allow to set ipv6 routes from userspace if disable_ipv6 has been
> enabled. The issue can be triggered using the following reproducer:
>
> - sysctl net.ipv6.conf.all.disable_ipv6=1
> - ip -6 route add a:b:c:d::/64 dev em1
> - ip -6 route show
> a:b:c:d::/64 dev em1 metric 1024 pref medium
>
> Fix it checking disable_ipv6 value in ip6_route_info_create routine
>
> Signed-off-by: Lorenzo Bianconi <lorenzo.bianc...@redhat.com>
> ---
> net/ipv6/route.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index 1d0eaa69874d..672fd7fdb037 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -2917,6 +2917,11 @@ static struct rt6_info *ip6_route_info_create(struct
> fib6_config *cfg,
> if (!dev)
> goto out;
>
> + if (idev->cnf.disable_ipv6) {
> + err = -EACCES;
you need an extack message telling the user that IPv6 is disabled on the
nexthop device.
> + goto out;
> + }
> +
> if (!(dev->flags & IFF_UP)) {
> NL_SET_ERR_MSG(extack, "Nexthop device is not up");
> err = -ENETDOWN;
>
