Re: [PATCH v5 02/39] x86/shstk: Add Kconfig option for shadow stack

From: Kees Cook
Date: Thu Jan 19 2023 - 19:40:52 EST


On Thu, Jan 19, 2023 at 01:22:40PM -0800, Rick Edgecombe wrote:
> From: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>
>
> Shadow stack provides protection for applications against function return
> address corruption. It is active when the processor supports it, the
> kernel has CONFIG_X86_SHADOW_STACK enabled, and the application is built
> for the feature. This is only implemented for the 64-bit kernel. When it
> is enabled, legacy non-shadow stack applications continue to work, but
> without protection.
>
> Since there is another feature that utilizes CET (Kernel IBT) that will
> share implementation with shadow stacks, create CONFIG_CET to signify
> that at least one CET feature is configured.
>
> Tested-by: Pengfei Xu <pengfei.xu@xxxxxxxxx>
> Tested-by: John Allen <john.allen@xxxxxxx>
> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

--
Kees Cook