Re: [PATCH 3/7] security: introduce kernel_fw_from_file hook

Luis R. Rodriguez
2014-07-22T22:11:53Z

On Tue, Jul 22, 2014 at 1:55 PM, Kees Cook <keescook@chromium.org> wrote:
> On Tue, Jul 22, 2014 at 12:39 PM, Luis R. Rodriguez <mcgrof@suse.com> wrote:
>> On Mon, Jul 14, 2014 at 3:31 PM, Kees Cook <keescook@chromium.org> wrote:
>>> Yup, with this and the module hook, adding a similar hook for kexec
>>> makes sense as well. A paranoid kernel doesn't want to trust anything
>>> it's loading from userspace. :)
>>
>> Well I'm actually wondering if we could generalize requiring hooks or
>> not for LSM as part of the general kobject definition. Then we
>> wouldn't need to keep growing hooks for modules, firmware, kexec
>> images, etc, but instead using the interfaces for kobjects and who
>> depend on them. How that would actually look -- I'm not sure, but just
>> a thought.
>
> Yeah, there does seem to be a repeated "get a thing from userspace"
> method here, but the interfaces have been rather scattered so far. I
> haven't seen an obvious way to consolidate them yet.

If we are going to be adding a new system call for each type of
userspace object to help LSMs with requirements I wonder if its a
worthy endeavor to review. This series didn't add one but you had
mentioned finit_module() for example, are we going to want one for
finit_firmware() finit_kexec_image(), etc?

Luis