Re: [PATCH 07/12] driver/char: use correct format characters

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Jun 09, 2022 at 10:16:26PM +0000, Bill Wendling wrote:
> From: Bill Wendling <isanbard@gmail.com>

Why isn't that matching your From: line in the email?

> 
> When compiling with -Wformat, clang emits the following warnings:

Is that ever a default build option for the kernel?

> 
> drivers/char/mem.c:775:16: error: format string is not a string literal (potentially insecure) [-Werror,-Wformat-security]
>                               NULL, devlist[minor].name);
>                                     ^~~~~~~~~~~~~~~~~~~
> 
> Use a string literal for the format string.
> 
> Link: https://github.com/ClangBuiltLinux/linux/issues/378
> Signed-off-by: Bill Wendling <isanbard@gmail.com>
> ---
>  drivers/char/mem.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/char/mem.c b/drivers/char/mem.c
> index 84ca98ed1dad..32d821ba9e4d 100644
> --- a/drivers/char/mem.c
> +++ b/drivers/char/mem.c
> @@ -772,7 +772,7 @@ static int __init chr_dev_init(void)
>  			continue;
>  
>  		device_create(mem_class, NULL, MKDEV(MEM_MAJOR, minor),
> -			      NULL, devlist[minor].name);
> +			      NULL, "%s", devlist[minor].name);

Please explain how this static string can ever be user controlled.

thanks,

greg k-h