[PATCH 5/5] modules: only allow symbol_get of EXPORT_SYMBOL_GPL modules

[Greg Kroah-Hartman]

On Mon, Jul 31, 2023 at 10:38:06AM +0200, Christoph Hellwig wrote:
> It has recently come to my attention that nvidia is circumventing the
> protection added in 262e6ae7081d ("modules: inherit
> TAINT_PROPRIETARY_MODULE") by importing exports from their propriertary
> modules into an allegedly GPL licensed module and then rexporting them.
> 
> Given that symbol_get was only ever inteded for tightly cooperating
> modules using very internal symbols it is logical to restrict it to
> being used on EXPORY_SYMBOL_GPL and prevent nvidia from costly DMCA

"EXPORT"  :)

> circumvention of access controls law suites.
> 
> All symbols except for four used through symbol_get were already exported
> as EXPORT_SYMBOL_GPL, and the remaining four ones were switched over in
> the preparation patches.
> 
> Fixes: 262e6ae7081d ("modules: inherit TAINT_PROPRIETARY_MODULE")
> Signed-off-by: Christoph Hellwig <hch at lst.de>

Thanks for fixing this hole up, it's much needed.

Reviewed-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>