Re: [PATCH 06/17] kthread: cfi: disable callback pointer check with modules

Kees Cook
2021-03-12T02:44:27Z

On Thu, Mar 11, 2021 at 04:49:08PM -0800, Sami Tolvanen wrote:
> With CONFIG_CFI_CLANG, a callback function passed to
> __kthread_queue_delayed_work from a module points to a jump table
> entry defined in the module instead of the one used in the core
> kernel, which breaks function address equality in this check:
>
> WARN_ON_ONCE(timer->function != kthread_delayed_work_timer_fn);
>
> Disable the warning when CFI and modules are enabled.
>
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

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Kees Cook