Subject: Re: [PATCH] mm: Remove HARDENED_USERCOPY_FALLBACK

From: Kees Cook <[email-masked]>
Date: Tue, 21 Sep 2021 12:01:12 -0700

On Tue, Sep 21, 2021 at 08:11:49AM +0200, Stephen Kitt wrote:
> This has served its purpose and is no longer used. All usercopy
> violations appear to have been handled by now, any remaining
> instances (or new bugs) will cause copies to be rejected.
> 
> This isn't a direct revert of commit 2d891fbc3bb6 ("usercopy: Allow
> strict enforcement of whitelists"); since usercopy_fallback is
> effectively 0, the fallback handling is removed too.
> 
> This also removes the usercopy_fallback module parameter on
> slab_common.
> 
> Link: https://github.com/KSPP/linux/issues/153
> Signed-off-by: Stephen Kitt <[email-masked]>
> Suggested-by: Kees Cook <[email-masked]>

Thanks for doing this!

Acked-by: Kees Cook <[email-masked]>

-- 
Kees Cook