[PATCH v1 1/5] fbtft: Make sure string is NULL terminated

[Steven Price]

On 20/11/2019 09:57, Andy Shevchenko wrote:
> New GCC warns about inappropriate use of strncpy():
> 
> drivers/staging/fbtft/fbtft-core.c: In function ‘fbtft_framebuffer_alloc’:
> drivers/staging/fbtft/fbtft-core.c:665:2: warning: ‘strncpy’ specified bound 16 equals destination size [-Wstringop-truncation]
>   665 |  strncpy(info->fix.id, dev->driver->name, 16);
>       |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Later on the copy is being used with the assumption to be NULL terminated.
> Make sure string is NULL terminated by switching to snprintf().

Even better would be strscpy():

	strscpy(info->fix.id, dev->driver->name, sizeof(info->fix.id));

Steve

> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
> ---
>  drivers/staging/fbtft/fbtft-core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/fbtft/fbtft-core.c b/drivers/staging/fbtft/fbtft-core.c
> index a0a67aa517f0..61f0286fb157 100644
> --- a/drivers/staging/fbtft/fbtft-core.c
> +++ b/drivers/staging/fbtft/fbtft-core.c
> @@ -666,7 +666,7 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
>  	fbdefio->deferred_io =     fbtft_deferred_io;
>  	fb_deferred_io_init(info);
>  
> -	strncpy(info->fix.id, dev->driver->name, 16);
> +	snprintf(info->fix.id, sizeof(info->fix.id), "%s", dev->driver->name);
>  	info->fix.type =           FB_TYPE_PACKED_PIXELS;
>  	info->fix.visual =         FB_VISUAL_TRUECOLOR;
>  	info->fix.xpanstep =	   0;
>