Script to reproduce bug 58691 in linux kernel

bug_58691.sh

#!/bin/bash

# Reproduce https://bugzilla.kernel.org/show_bug.cgi?id=58691
# Depends: sshd listening :22, ssh, unshare, setkey(ipsec-tools), iproute2, ip6_tunnel.ko, veth, radvd

modprobe ip6_tunnel

export MYPID=$$

rm /tmp/unshare_pid
while true; do
    if [ -e /tmp/unshare_pid ]; then
        #ip link set qqq_2 netns `cat /tmp/unshare_pid`
        ip link set veth_cm mtu 1280 up
        ip -6 addr  add fc::1 dev veth_cm
        ip -6 route add fc::2 dev veth_cm

        setkey -c << EOF
            spdadd fc::1 fc::2 any -P out ipsec esp/transport//require  ah/transport//require ;
            spdadd fc::2 fc::1 any -P in ipsec esp/transport//require  ah/transport//require; 
            add fc::2 fc::1 esp 123457 -E rijndael-cbc 0x0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF ;
            add fc::1 fc::2 esp 123457 -E rijndael-cbc 0x0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF ;
            add fc::2 fc::1 ah 123456 -A hmac-sha256 0x0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF ;
            add fc::1 fc::2 ah 123456 -A  hmac-sha256 0x0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF ;
EOF

        ip -6 tunnel add name qqq mode ipip6 local fc::1 remote fc::2 dev veth_cm
        ip link set qqq mtu 1280 up
        ip -4 addr  add 192.168.72.1 dev qqq
        ip -4 route add 192.168.72.2 dev qqq

        echo 1 > /proc/sys/net/ipv6/conf/all/forwarding
        cat > /tmp/bug_radvd.conf << \EOF
            interface veth_cm {
                AdvSendAdvert on;
                AdvLinkMTU 1280;

                MaxRtrAdvInterval 20;
                MinRtrAdvInterval 5;

                AdvDefaultLifetime 30;
                AdvSourceLLAddress off;

                AdvHomeAgentFlag on;

                prefix 2001:470:7bd6:c004::/64 {
                    AdvOnLink on;
                    AdvAutonomous on;
                    AdvValidLifetime 60;
                    AdvPreferredLifetime 30;
                    AdvRouterAddr off;
                };
            };
EOF
        killall radvd
        radvd -C /tmp/bug_radvd.conf

        rm /tmp/unshare_pid

        break;
    else
        sleep 0.1
    fi
done &


unshare -n sh << \EOF2
    ip link add name veth_c  type veth peer name veth_cm
    ip link set veth_cm netns $MYPID

    echo $$ > /tmp/unshare_pid

    #until ip link show qqq_2 2> /dev/null; do sleep 0.1; done

    ip link set veth_c mtu 1280 up
    ip -6 addr  add fc::2 dev veth_c
    ip -6 route add fc::1 dev veth_c

    setkey -c << EOF
        spdadd fc::1 fc::2 any -P in ipsec esp/transport//require  ah/transport//require ;
        spdadd fc::2 fc::1 any -P out ipsec esp/transport//require  ah/transport//require; 
        add fc::2 fc::1 esp 123457 -E rijndael-cbc 0x0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF ;
        add fc::1 fc::2 esp 123457 -E rijndael-cbc 0x0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF ;
        add fc::2 fc::1 ah 123456 -A hmac-sha256 0x0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF ;
        add fc::1 fc::2 ah 123456 -A  hmac-sha256 0x0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF ;
EOF

    ip -6 tunnel add name qqq mode ipip6 local fc::2 remote fc::1 dev veth_c
    ip link set qqq mtu 1280 up
    ip -4 addr  add 192.168.72.2 dev qqq
    ip -4 route add 192.168.72.1 dev qqq

    echo 0 > /proc/sys/net/ipv6/conf/all/forwarding

    until ip -6 addr | grep 2001; do sleep 0.2; done

    #bash -i < /dev/tty
    ssh 192.168.72.1 < /dev/tty
EOF2