[U-Boot] [PATCH v4 1/1] usb: gadget: avoid variable name clipping in cb_getvar

[Marek Vasut]

On 03/13/2017 11:30 AM, Nicolas le bayon wrote:
> From: Nicolas Le Bayon <nlebayon at gmail.com>
> 
> Instead of using a fixed-size array to store variable name, preferring a
> dynamic allocation treats correctly all variable name lengths.
> Variable names are growing through releases and features. By this way, name
> clipping is prevented.
> 
> Signed-off-by: Nicolas Le Bayon <nlebayon at gmail.com>
> ---
>  drivers/usb/gadget/f_fastboot.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_
> fastboot.c
> index 2160b1c..11005e0 100644
> --- a/drivers/usb/gadget/f_fastboot.c
> +++ b/drivers/usb/gadget/f_fastboot.c
> @@ -432,9 +432,16 @@ static void cb_getvar(struct usb_ep *ep, struct
> usb_request *req)
>                 else
>                         strcpy(response, "FAILValue not set");
>         } else {
> -               char envstr[32];
> +               char *envstr;
> 
> -               snprintf(envstr, sizeof(envstr) - 1, "fastboot.%s", cmd);
> +               envstr = malloc(strlen("fastboot.") + strlen(cmd) + 1);
> +               if (!envstr) {
> +                       error("malloc fail");

Just drop the error() here ... if your malloc failed, you're screwed anyway.

The rest looks OK IMO .

> +                       fastboot_tx_write_str("FAILmalloc error");
> +                       return;
> +               }
> +
> +               sprintf(envstr, "fastboot.%s", cmd);
>                 s = getenv(envstr);
>                 if (s) {
>                         strncat(response, s, chars_left);
> @@ -442,6 +449,8 @@ static void cb_getvar(struct usb_ep *ep, struct
> usb_request *req)
>                         printf("WARNING: unknown variable: %s\n", cmd);
>                         strcpy(response, "FAILVariable not implemented");
>                 }
> +
> +               free(envstr);
>         }
>         fastboot_tx_write_str(response);
>  }
> --
> 1.9.1
> 


-- 
Best regards,
Marek Vasut