From: Guillaume Nault
Date: Fri, 13 Oct 2017 19:22:35 +0200
> When pppol2tp_session_ioctl() is called by pppol2tp_tunnel_ioctl(),
> the session may be unconnected. That is, it was created by
> pppol2tp_session_create() and hasn't been connected with
> pppol2tp_connect(). In this case, ps->sock is
When pppol2tp_session_ioctl() is called by pppol2tp_tunnel_ioctl(),
the session may be unconnected. That is, it was created by
pppol2tp_session_create() and hasn't been connected with
pppol2tp_connect(). In this case, ps->sock is NULL, so we need to check
for this case in order to avoid dereferenci
