Re: [PATCH 8/8] modules: inherit TAINT_PROPRIETARY_MODULE

From: daniel
Date: Tue Aug 04 2020 - 14:52:12 EST


On Thu, Jul 30, 2020 at 08:10:27AM +0200, Christoph Hellwig wrote:
> If a TAINT_PROPRIETARY_MODULE exports symbol, inherit the taint flag
> for all modules importing these symbols, and don't allow loading
> symbols from TAINT_PROPRIETARY_MODULE modules if the module previously
> imported gplonly symbols. Add a anti-circumvention devices so people
> don't accidentally get themselves into trouble this way.
>
> Comment from Greg:
> Ah, the proven-to-be-illegal "GPL Condom" defense :)
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

If this helps to get the next gpu related entertainment at least cc'ed to
dri-devel, maybe even using an upstream driver, I'm all for it.

Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>

> ---
> include/linux/module.h | 1 +
> kernel/module.c | 12 ++++++++++++
> 2 files changed, 13 insertions(+)
>
> diff --git a/include/linux/module.h b/include/linux/module.h
> index 30b0f5fcdb3c37..e30ed5fa33a738 100644
> --- a/include/linux/module.h
> +++ b/include/linux/module.h
> @@ -389,6 +389,7 @@ struct module {
> unsigned int num_gpl_syms;
> const struct kernel_symbol *gpl_syms;
> const s32 *gpl_crcs;
> + bool using_gplonly_symbols;
>
> #ifdef CONFIG_UNUSED_SYMBOLS
> /* unused exported symbols. */
> diff --git a/kernel/module.c b/kernel/module.c
> index afb2bfdd5134b3..04f993863ae417 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -1456,6 +1456,18 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod,
> if (!sym)
> goto unlock;
>
> + if (license == GPL_ONLY)
> + mod->using_gplonly_symbols = true;
> +
> + if (owner && test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints)) {
> + if (mod->using_gplonly_symbols) {
> + sym = NULL;
> + goto getname;
> + }
> + add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
> + LOCKDEP_NOW_UNRELIABLE);
> + }
> +
> if (!check_version(info, name, mod, crc)) {
> sym = ERR_PTR(-EINVAL);
> goto getname;
> --
> 2.27.0
>

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch