Re: [PATCH] crypto: marvell/cesa - Fix type mismatch warning

[Kees Cook]

On Tue, May 23, 2023 at 10:33:04AM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
> 
> Commit df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3") uncovered
> a type mismatch in cesa 3des support that leads to a memcpy beyond the
> end of a structure:
> 
> In function 'fortify_memcpy_chk',
>     inlined from 'mv_cesa_des3_ede_setkey' at drivers/crypto/marvell/cesa/cipher.c:307:2:
> include/linux/fortify-string.h:583:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
>   583 |                         __write_overflow_field(p_size_field, size);
>       |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> This is probably harmless as the actual data that is copied has the correct
> type, but clearly worth fixing nonetheless.
> 
> Fixes: 4ada48397823 ("crypto: marvell/cesa - add Triple-DES support")
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-- 
Kees Cook