Re: [PATCH] kgdbts: Passing ekgdbts to command line causes panic

[Daniel Thompson <daniel.thompson@linaro.org>]

On Mon, Dec 28, 2020 at 09:58:58AM +0800, Defang Bo wrote:
> Similar to commit<1bd54d851f50>("kgdboc: Passing ekgdboc to command line causes panic"),
> kgdbts_option_setup does not check input argument before passing it to strlen.
> The argument would be a NULL pointer.

Something seems to be missing here.

The ekgdbts parameter mentioned in the subject line doesn't exist so
how can including it on the kernel command line could provoke a panic.

Please can you share the kernel boot arguments you used when you tested
this patch?


Daniel.


> Signed-off-by: Defang Bo <bodefang@126.com>
> ---
>  drivers/misc/kgdbts.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c
> index 945701b..b077547 100644
> --- a/drivers/misc/kgdbts.c
> +++ b/drivers/misc/kgdbts.c
> @@ -1057,6 +1057,11 @@ static void kgdbts_run_tests(void)
>  
>  static int kgdbts_option_setup(char *opt)
>  {
> +	if (!opt) {
> +		pr_err("kgdbts: config string not provided\n");
> +		return -EINVAL;
> +	}
> +
>  	if (strlen(opt) >= MAX_CONFIG_LEN) {
>  		printk(KERN_ERR "kgdbts: config string too long\n");
>  		return -ENOSPC;
> -- 
> 2.7.4
>