Re: tc egress mirror to tunnel causing hard lock

Wanted to follow-up in order to determine if someone might have
thoughts on why applying the following causes a virtual guest to
freeze:

tc filter add dev ens33 parent 100: \
    protocol all \
    u32 match u8 0 0 \
    action mirred egress mirror dev tun0

Experiencing symptoms in several VPS providers.

On Fri, May 12, 2017 at 1:43 PM, Stephen Reese <[email protected]> wrote:
> When I apply an egress mirror to a GRE or VXLAN tunnel, the Linux host
> locks up requiring a hard restart. I have tried Ubuntu and Debian. The
> ingress snippet works fine. I can apply the ingress and egress
> statements to a dummy or second real interface and everything works so
> it seems to be an issue with tunnels. Am I missing something or is
> this expected behavior?
>
> ip tunnel add tun0 mode gre remote 172.20.0.6 local 172.20.0.10 ttl 255
> ip link set tun0 up
> ip addr add 192.168.0.2/24 dev tun0
>
>
> # Ingress
> tc qdisc add dev ens33 ingress
> tc filter add dev ens33 parent ffff: \
>     protocol all \
>     u32 match u8 0 0 \
>     action mirred egress mirror dev tun0
>
> # Egress
> tc qdisc add dev ens33 handle 100: root prio
> # The following causes the system to lock up if applied to a tunnel,
> in this case tun0
> tc filter add dev ens33 parent 100: \
>     protocol all \
>     u32 match u8 0 0 \
>     action mirred egress mirror dev tun0