Re: [PATCH] iwlwifi: calib: Refactor iwl_calib_result usage for clarity

[Kalle Valo <kvalo@kernel.org>]

Kees Cook <keescook@chromium.org> writes:

> In preparation for FORTIFY_SOURCE performing run-time destination buffer
> bounds checking for memcpy(), refactor the use of struct iwl_calib_result:
>
> - Have struct iwl_calib_result contain struct iwl_calib_cmd since
>   functions expect to operate on the "data" flex array in "cmd", which
>   follows the "hdr" member.
> - Switch argument passing around to use struct iwl_calib_cmd instead of
>   struct iwl_calib_hdr to prepare functions to see the "data" member.
> - Change iwl_calib_set()'s "len" argument to a size_t since it is always
>   unsigned and is normally receiving the output of sizeof().
> - Add an explicit length sanity check in iwl_calib_set().
> - Adjust the memcpy() to avoid copying across the now visible composite
>   flex array structure.
>
> This avoids the future run-time warning:
>
>   memcpy: detected field-spanning write (size 8) of single field "&res->hdr" (size 4)
>
> Cc: Luca Coelho <luciano.coelho@intel.com>
> Cc: Kalle Valo <kvalo@codeaurora.org>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: Johannes Berg <johannes.berg@intel.com>
> Cc: linux-wireless@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Reported-by: Andy Lavr <andy.lavr@gmail.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>

Gregory, as this fixes a future warning can I take this directly to
wireless-next?

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