[PATCH] tools: kwbimage: Fix checksum calculation for v1 images

[Pali Rohár]

On Saturday 25 December 2021 20:50:19 Pierre Bourdon wrote:
> Recent changes caused fields in the image main header to be modified
> after the header checksum had already been computed. Move the checksum
> computation to once again be the last operation performed on the header.
> 
> Fixes: 2b0980c24027 ("tools: kwbimage: Fill the real header size into the main header")
> 
> Signed-off-by: Pierre Bourdon <delroth at gmail.com>

Thanks!

Reviewed-by: Pali Rohár <pali at kernel.org>


Stefan and Tom, could you please include this fixup patch into master
branch for upcoming release? During development we broke kwbimage /
mkimage generator and I think it is something which we should have fixed
in upcoming release (if it is not too late now...).

> ---
>  tools/kwbimage.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/kwbimage.c b/tools/kwbimage.c
> index 875f636c7a..0951d7861c 100644
> --- a/tools/kwbimage.c
> +++ b/tools/kwbimage.c
> @@ -1398,9 +1398,6 @@ static void *image_create_v1(size_t *imagesz, struct image_tool_params *params,
>  					       headersz, image, secure_hdr))
>  		return NULL;
>  
> -	/* Calculate and set the header checksum */
> -	main_hdr->checksum = image_checksum8(main_hdr, headersz);
> -
>  	*imagesz = headersz;
>  
>  	/* Fill the real header size without padding into the main header */
> @@ -1410,6 +1407,9 @@ static void *image_create_v1(size_t *imagesz, struct image_tool_params *params,
>  	main_hdr->headersz_lsb = cpu_to_le16(headersz & 0xFFFF);
>  	main_hdr->headersz_msb = (headersz & 0xFFFF0000) >> 16;
>  
> +	/* Calculate and set the header checksum */
> +	main_hdr->checksum = image_checksum8(main_hdr, headersz);
> +
>  	return image;
>  }
>  
> -- 
> 2.34.0
>