From: Guillaume Nault
Date: Mon, 14 Mar 2016 21:17:16 +0100
> Locking ppp_mutex must be done before dereferencing file->private_data,
> otherwise it could be modified before ppp_unattached_ioctl() takes the
> lock. This could lead ppp_unattached_ioctl() to override ->private_data,
> thus leaking
Locking ppp_mutex must be done before dereferencing file->private_data,
otherwise it could be modified before ppp_unattached_ioctl() takes the
lock. This could lead ppp_unattached_ioctl() to override ->private_data,
thus leaking reference to the ppp_file previously pointed to.
v2: lock all ppp_ioc
