On Wed, May 13, 2020 at 04:16:22PM +0000, Luis Chamberlain wrote: > On Wed, May 13, 2020 at 10:40:31AM -0500, Eric W. Biederman wrote: > > Luis Chamberlain <mcgrof@xxxxxxxxxx> writes: > > > > > Certain symbols are not meant to be used by everybody, the security > > > helpers for reading files directly is one such case. Use a symbol > > > namespace for them. > > > > > > This will prevent abuse of use of these symbols in places they were > > > not inteded to be used, and provides an easy way to audit where these > > > types of operations happen as a whole. > > > > Why not just remove the ability for the firmware loader to be a module? > > > > Is there some important use case that requires the firmware loader > > to be a module? > > > > We already compile the code in by default. So it is probably just > > easier to remove the modular support all together. Which would allow > > the export of the security hooks to be removed as well. > > Yeah, that's a better solution. The only constaint I am aware of is > we *cannot* change the name of the module from firmware_class since the > old fallback sysfs loader depends on the module name. So, so long as we > take care with that on built-in and document this very well, I think > we should be good. > > I checked the commit logs and this was tristate since the code was added > upstream, so I cannot see any good reason it was enabled as modular. > > Speaking with a *backports experience* hat on, we did have a use case > to use a module for it in case a new feature was added upstream which > was not present on older kernels. However I think that using a separate > symbol prefix would help with that. > > Would any Android stakeholders / small / embedded folks whave any issue > with this? Android has build in the firmware loading logic for a while now. Well, always, they have not had kernel modules for many years. That is changing but this logic is not getting moved to a kernel module as that would just be silly :) thanks, greg k-h
