[PATCH] tools: open FIT image for reading as O_RDONLY instead of O_RDWR

[Dragan Simic]

Hello Ahelenia,

Please see my comments below.

On 2024-03-20 14:08, Ahelenia Ziemiańska wrote:
> The only usage of the fd is for the single read() below;
> this prevented
> 	mkimage -f auto -A arm64 \
> 		-T kernel -C lz4 -d Image-6.6.15.lz4 \
> 		-b mt8173-elm-hana-6.6.15.dtb outf
> when the inputs were unwriteable.

s/unwriteable/unwritable/

Also, the patch subject could be moved to the patch description,
and the following could be used instead, as the subject:

     tools: open FIT image read-only

> 
> Link: https://bugs.debian.org/1063097
> Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli at nabijaczleweli.xyz>

Looking good to me.  Opening the file read-only is also good
from the standpoint of using least privilege to perform the
required operation.

With the small nitpicks above,

Reviewed-by: Dragan Simic <dsimic at manjaro.org>

> ---
>  tools/fit_image.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/fit_image.c b/tools/fit_image.c
> index beef1fa8..0fccfbb4 100644
> --- a/tools/fit_image.c
> +++ b/tools/fit_image.c
> @@ -137,7 +137,7 @@ static int fdt_property_file(struct
> image_tool_params *params,
>  	int ret;
>  	int fd;
> 
> -	fd = open(fname, O_RDWR | O_BINARY);
> +	fd = open(fname, O_RDONLY | O_BINARY);
>  	if (fd < 0) {
>  		fprintf(stderr, "%s: Can't open %s: %s\n",
>  			params->cmdname, fname, strerror(errno));