iproute2 invalid argument mpls labels

I updated the kernel 4.12.6. When the mote is hung on the route more than 8 mpls of marks through iproute2, I get the following:

root@ne-vlezay80:~# ip route add 10.10.10.0/24 encap mpls 50/60/70/80/90/100/110/120/130 dev lo
RTNETLINK answers: Invalid argument

root@ne-vlezay80:~# ip route add 10.10.10.0/24 encap mpls 50/60/70/80/90/100/110/120 dev lo
root@ne-vlezay80:~#

root@ne-vlezay80:~# ip r
default via 10.247.0.1 dev ic-br0 proto zebra metric 20 
10.10.10.0/24  encap mpls  ///////120 dev lo scope link 

root@ne-vlezay80:~# cat /usr/src/linux-4.12.6/net/mpls/internal.h|grep MAX_NEW
#define MAX_NEW_LABELS 30
root@ne-vlezay80:~# 

What is the problem, and how can more than 8 MPLS markers be hung on through iproute2?

root@ne-vlezay80:~# uname -r
4.12.6
root@ne-vlezay80:~# 

On Tue, 15 Aug 2017 11:17:27 +0300
Алексей Болдырев         [off-list ref] wrote:

I updated the kernel 4.12.6. When the mote is hung on the route more than 8 mpls of marks through iproute2, I get the following:

root@ne-vlezay80:~# ip route add 10.10.10.0/24 encap mpls 50/60/70/80/90/100/110/120/130 dev lo
RTNETLINK answers: Invalid argument

root@ne-vlezay80:~# ip route add 10.10.10.0/24 encap mpls 50/60/70/80/90/100/110/120 dev lo
root@ne-vlezay80:~#

root@ne-vlezay80:~# ip r
default via 10.247.0.1 dev ic-br0 proto zebra metric 20 
10.10.10.0/24  encap mpls  ///////120 dev lo scope link 

root@ne-vlezay80:~# cat /usr/src/linux-4.12.6/net/mpls/internal.h|grep MAX_NEW
#define MAX_NEW_LABELS 30
root@ne-vlezay80:~# 

What is the problem, and how can more than 8 MPLS markers be hung on through iproute2?

root@ne-vlezay80:~# uname -r
4.12.6
root@ne-vlezay80:~# 

iproute2 just reports what the kernel response is. The invalid argument error 
comes from the kernel.