Re: [RFC PATCH v2] fw_lockdown: new micro LSM module to prevent loading unsigned firmware

[Luis R. Rodriguez]

On Mon, Nov 13, 2017 at 08:51:54PM +0100, Luis R. Rodriguez wrote:
> On Mon, Nov 13, 2017 at 02:36:47PM -0500, Mimi Zohar wrote:
> > On Mon, 2017-11-13 at 20:05 +0100, Luis R. Rodriguez wrote:
> > > > + * fw_lockdown_read_file - prevent loading of unsigned firmware
> > > > + * @file: pointer to firmware
> > > > + * @read_id: caller identifier
> > > > + *
> > > > + * Prevent loading of unsigned firmware in lockdown mode.
> > > > + */
> > > > +static int fw_lockdown_read_file(struct file *file, enum kernel_read_file_id id)
> > > > +{
> > > > +	if (id == READING_FIRMWARE) {
> > > > +		if (!is_ima_appraise_enabled() &&
> > > > +		    kernel_is_locked_down("Loading of unsigned firmware"))
> > > > +			return -EACCES;
> > > > +	}

We also have READING_FIRMWARE_PREALLOC_BUFFER now. So the above
is missing a check for that as well.

  Luis