Re: [PATCH 2/2] common/spl: guard against buffer overflow in spl_fit_get_image_name()

[E Shattow <e@freeshell.de>]

On 6/24/25 08:34, Heinrich Schuchardt wrote:
> A malformed FIT image could have an image name property that is not NUL
> terminated. Reject such images.
> 
> Reported-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
> ---
>  common/spl/spl_fit.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/common/spl/spl_fit.c b/common/spl/spl_fit.c
> index e250c11ebbd..25f3c822a49 100644
> --- a/common/spl/spl_fit.c
> +++ b/common/spl/spl_fit.c
> @@ -73,7 +73,7 @@ static int spl_fit_get_image_name(const struct spl_fit_info *ctx,
>  				  const char **outname)
>  {
>  	struct udevice *sysinfo;
> -	const char *name, *str;
> +	const char *name, *str, *end;
>  	__maybe_unused int node;
>  	int len, i;
>  	bool found = true;
> @@ -83,11 +83,17 @@ static int spl_fit_get_image_name(const struct spl_fit_info *ctx,
>  		debug("cannot find property '%s': %d\n", type, len);
>  		return -EINVAL;
>  	}
> +	/* A string property should be NUL terminated */
> +	end = name + len - 1;
> +	if (!len || *end) {
> +		debug("malformed property '%s'\n", type);
> +		return -EINVAL;
> +	}
>  
>  	str = name;
>  	for (i = 0; i < index; i++) {
>  		str = strchr(str, '\0') + 1;
> -		if (!str || (str - name >= len)) {
> +		if (str > end) {
>  			found = false;
>  			break;
>  		}

Tested-by: E Shattow <e@freeshell.de>