[U-Boot] [PATCH v6 1/1] usb: gadget: avoid variable name clipping in cb_getvar

[Lukasz Majewski]

On Mon, 3 Apr 2017 11:28:44 +0200
Nicolas le bayon <nlebayon at gmail.com> 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.

Acked-by: Lukasz Majewski <lukma at denx.de>

> 
> Signed-off-by: Nicolas Le Bayon <nlebayon at gmail.com>
> Reviewed-by: Marek Vasut <marex at denx.de>

Marek, could you pull this patch directly to -usb tree? I do not have
more -dfu patches to pull to this merge window. Thanks in advance.


> ---
> 
> Changes in v2:
> - instead of using a bigger fixed size, use malloc to fit with size
> needs
> 
> Changes in v3:
> - v2 was an error (intermediate version), so propose a complete one
> 
> Changes in v4:
> - be more explicit and detailed in label and description fields
> - remove intermediate variable only used one time
> - be more explicit in error message
> - fix indent issue
> 
> Changes in v5:
> - drop an unuseful error() call
> 
> Changes in v6:
> - add Marek review approval
> 
>  drivers/usb/gadget/f_fastboot.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_
> fastboot.c
> index 2160b1c..7cd6d24 100644
> --- a/drivers/usb/gadget/f_fastboot.c
> +++ b/drivers/usb/gadget/f_fastboot.c
> @@ -432,9 +432,15 @@ 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) {
> +                       fastboot_tx_write_str("FAILmalloc error");
> +                       return;
> +               }
> +
> +               sprintf(envstr, "fastboot.%s", cmd);
>                 s = getenv(envstr);
>                 if (s) {
>                         strncat(response, s, chars_left);
> @@ -442,6 +448,8 @@ 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,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de